volume I
summary
ANALYSIS OF
AND COSTS
Of
RETROFIT EMISSION
CONTROL SYSTEMS
for
USED MOTOR
Environmental Protection Agency
MAY 1972
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volume I
summary
ANALYSIS OF
AND COSTS
of
RETROFIT EMISSION
CONTROL SYSTEMS
for
USED MOTOR
VEHICLES
prepared under
EPA Contract 68-04-0038
by
Olson Laboratories, Inc.
500 East Orangethorpe Avenue
Anaheim, California 92801
In Association With Northrop Corporation
Report 71Y233
MAY 1972
for
ENVIRONMENTAL PROTECTION AGENCY
Office of Air Programs
Division of Emission Control Technology
2565 Plymouth Road
Ann Arbor, Michigan 48105
Approved by:
D. D. Foulds
Vice President
Olson Laboratories, Inc.
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FOREWORD
The Environmental Protection Agency, as Administrator of the Clean Air Amendments
Act of 1970, is required to assist States and air pollution control agencies in
meeting national ambient air quality standards and mobile or stationary source
emission standards, by issuing information on control techniques. Contract
68-04-0038 was performed with the Office of Air Programs, Division of Emission Con-
trol Technology, to determine what emission control techniques are feasible for
retrofit to used cars, considering emission reduction effectiveness, costs, effect
on vehicle performance, and the facilities and labor skills required for retrofit
device installation and eventual maintenance and inspection. This report documents
the results obtained, the pertinent data upon which the results are based, the
techniques of test and analysis, and the recommendations for future programs
to implement the results. The report consists of the following six volumes:
I. Program Summary: Highlights the principal program results and
conclusions as to the overall feasibility of retrofit methods for
.vehicle emission control. Provides guidelines for the evaluation of
retrofit approaches and the implementation of control programs.
II. System Descriptions: Documents the physical, functional, and
performance characteristics of the candidate retrofit methods and
their installation requirements and costs.
III. Performance Analysis: Documents the relative effectiveness and costs
of retrofit methods, the techniques of analysis and testing, and the
assumptions and rationale upon which the analysis was based.
IV. Test and Analytical Procedures: Documents the approach to the overall
program objectives and the tasks and procedures implemented to meet
the objectives.
V. Appendices: Documents the raw data obtained from retrofit development
sources and data of overall applicability to the report.
VI. Addendum for Durability Tests: Documents the results of 25,000-mile
durability tests on four representative retrofit devices.
iii
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ABSTRACT
The purpose of this EPA-contracted program was to examine the effectiveness and
costs of retrofit methods for control of emissions from gasoline-powered, light-duty
used automobiles. This six-volume report provides the results of an extensive eval-
uation of current retrofit technology to States and agencies which have to establish
or evaluate automotive emission control programs. It also provides detailed guide-
lines and an evaluation methodology to assist in the development of specific air
pollution control programs or abatement strategies using retrofit devices as they
apply to used car emission control requirements. The report presents a summary of
all known retrofit emission control techniques for used cars in terms of emission
reduction effectiveness, costs, effect on the vehicle's performance, and the facili-
ties and labor skill needed for device installation, maintenance, and inspection.
The term "retrofit method" as used in this program is defined as "any device or
system that may be added to a car and/or any modification or adjustment, beyond that
of regular vehicle maintenance, which may be made to vehicles to reduce their emis-
sions. "(1) Regular vehicle maintenance, engine tuneup, the General Motors, Ford,
and Chrysler used car retrofit systems, as well as vehicle inspection programs, were
specifically excluded from study. Other programs have studied, or are currently
studying, these alternate approaches.
A thorough search was made for all sources of information on all known retrofit
methods, developers, and producers. Input data from the participating developers
and producers were used in the evaluation process and to categorize the principles
of retrofit device operation. Generic groups of: (1) exhaust emission control, (2)
crankcase blowby control, (3) evaporative emission control, and (4) combinations
were evaluated. The study emphasis, however, was placed on exhaust emission control
approaches.
Several representative devices were actually tested to provide exhaust emissions,
fuel consumption, and driveability performance data which are considered to be typ-
ical for the existing used car population. The test program was performed on used
cars without factory installed exhaust control systems.
Concurrent with the test program an engineering analysis was conducted on each
retrofit system to document technical characteristics, costs, and effects on vehicle
performance. The data obtained, both from the retrofit tests and the engineering
analysis, were then processed through an evaluation methodology especially developed
Environmental Protection Agency Contract 68-04-0038, Analysis of Effectiveness
and Costs of Retrofit Emission Control Systems for Used Vehicles, 30 June 1971
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to analyze the principal performance parameters of the different retrofit systems.
The methodology developed is applicable to the evaluation of any exhaust emission
control method, whether for cars that may or may not already be equipped with other
emission control systems.
The study showed that a large number of retrofit methods and prototype devices are
available for the majority of the used car population. Most can be readily mass
produced and marketed if the necessary economic incentives arise. They cover a wide
spectrum of effectiveness and cost. Those devices which are most effective in reduc-
ing emissions are also generally the most expensive. The study indicated that cer-
tain of these retrofit devices are technically feasible, but that careful tradeoffs
may be required between emission reduction effectiveness and costs to achieve an
optimum solution to the air quality control requirements of different regions.
The problem of durability (device performance versus mileage accumulation) was also
investigated in the program. The evaluation of the durability test results is being
completed and will be covered in Volume VI, which is to be published shortly.
vi
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ACKNOWLEDGMENTS
This program was conducted under the direction and with the assistance of Dr. Jose
L. Bascunana, Project Officer of the Environmental Protection Agency. Emission
Control Technology, Inc., provided the methodology for performance analysis under
a subcontract agreement with Olson Laboratories, Inc.
The accomplishment of this program was made possible by the cooperation and
assistance of the many developers and manufacturers of retrofit devices. Their
contribution of coordination time, data, and retrofit device hardware is very
much appreciated.
vii
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GLOSSARY
AMA Automobile Manufacturers Association
CEI Cost Effectiveness Index
CI Cost Index
CID Cubic inch displacement
CNG Compressed natural gas
CO Carbon monoxide
CVS Constant volume sampling
DI Driveability Index
EGR Exhaust gas recirculation
El Emission Index
EPA Environmental Protection Agency
gm/mi Grams per mile
HC Hydrocarbons
LNG Liquefied natural gas
LPG Liquefied petroleum gas
MMBM Mean-miles-before-maintenance
MMBPF Mean-miles-before-partial-failure
MMBTF Mean-miles-before-total-failure
mph Miles per hour
mpg Miles per gallon
MTTM Mean-time-to-maintain
MTTR Mean-time-to-repair
NDIR Nondispersive infrared
NOx Oxides of nitrogen
OEM Original equipment
PCV Positive crankcase ventilation
PI Performance Index
ppm Parts per million
SAE Society of Automotive Engineers
WOT Wide open throttle
viii
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CONTENTS (CONTINUED
Table Page
4-3 Average Percentage Exhaust Emission Reduction of Devices Evalu-
ated in Retrofit Program - Listed by Device Classification . . . 4-8
4-4 Percentage Exhaust Emission Reduction of Devices Tested in
Retrofit Program 4-12
4-5 Mean Percentage Emission Reduction and 90 Percent Confidence
Intervals for Exhaust Emission Control Retrofit Systems Tested
at Anaheim, California and Taylor, Michigan . . 4-15
4-6 Driveability and Safety Characteristics for Devices Tested in
Retrofit Program 4-20
4-7 Reliability and Corrective Maintenance Estimates of Devices
Evaluated in Retrofit Program 4-24
4-8 Preventive Maintenance Estimates of Devices Evaluated in
Retrofit Program 4-28
4-9 Initial and Recurring Costs of Devices Evaluated in Retrofit
Program 4-37
4-10 Installation and Skill Level Requirements Summary 4-39
5-1 Performance Summary of Devices Evaluated in Retrofit Program . . . 5-2
6-1 Light-Duty Vehicle Population and Type of Emission Control .... 6-2
6-2 Development Status and Applicability of Devices Evaluated in
Retrofit Program 6-6
XI
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CONTENTS
Section Page
FOREWORD iii
ABSTRACT v
ACKNOWLEDGMENTS vii
GLOSSARY viii
1 SUMMARY OF RESULTS AND CONCLUSIONS 1-1
1.1 Fundamental Results and Conclusions 1-1
1.2 Retrofit Device Classification and Descriptions 1-4
1.3 Retrofit Device Performance 1-9
1.4 Evaluation Methodology 1-15
1.5 Development Status and Applicability 1-15
1.6 Guidelines for Selecting and Implementing Feasible
Retrofit Methods 1-17
1.7 Recommendations 1-18
2 RETROFIT PROGRAM APPROACH 2-1
2.1 Retrofit Method Survey 2-1
2.2 Retrofit Method Screening Evaluation 2-2
2.3 Engineering Analysis 2-3
"2.4 Test Program 2-4
2.5 Performance Analysis 2-6
3 EVALUATION METHODOLOGY 3-1
3.1 Criteria Index 3-1
3.2 Performance Index 3-2
3.3 Cost Effectiveness Index 3-3
3.4 Sensitivity Analysis 3-4
4 RETROFIT DEVICE EVALUATIONS . 4-1
4.1 Emission Reduction 4-1
4.2 Driveability and Safety 4-18
4.3 Reliability and Maintainability 4-22
4.4 Initial and Recurring Costs 4-35
4.5 Installation and Skill Level Requirements 4-36
5 PERFORMANCE ANALYSIS 5-1
5.1 Criteria Index 5-1
5.2 Performance Index 5-3
5.3 Cost Effective Index 5-4
5.4 Feasibility 5-5
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CONTENTS (CONTINUED)
Section Page
6 RETROFIT DEVICE DEVELOPMENT STATUS AND VEHICLE APPLICABILITY ... 6-1
6.1 Vehicle Applicability of Retrofit Devices 6-1
6.2 Retrofit Device Development Status and Applicability
Summary 6-5
7 GUIDELINES FOR SELECTING AND IMPLEMENTING RETROFIT METHODS ..... 7-1
7.1 Defining the Required Emission Reduction . 7-1
7.2 Defining the Retrofit Vehicle Population 7-2
7.3 Identifying Candidate Retrofit Methods 7-2
7.4 Determining Cost Effective Retrofit Methods 7-2
7.5 Defining the Certification Program 7-3
7.6 Cost Effectiveness Studies of Alternative Programs 7-3
7.7 Preparing an Implementation Plan 7-3
7.8 Implementing the Plan 7-3
Append ix
A Sample Performance Evaluation Methodology Calculation ...... A-l
B Retrofit System Description Index B-l
C Tables of Contents for Volumes II, III, IV, V, and VI C-l
Figure
1-1
4-1
ILLUSTRATIONS
Pooled Mean Exhaust Emission Reduction of Devices Tested in the
Retrofit Program
Percentage Exhaust Emission Reduction Means and 90% Confidence
Limits for Exhaust Emission Control Retrofit Systems Tested at
Anaheim, California, and Taylor, Michigan .....
Page
1-11
4-16
TABLES
Table
1-1
1-2
2-1
4-1
4-2
Classification of Retrofit Methods . .,
Performance Parameters and Evaluation Criteria ,
Retrofit System Types Tested in Retrofit Program .
Devices Evaluated in the Retrofit Program
Average Percentage Exhaust Emission Reduction by Test Procedure
for Devices Evaluated in Retrofit Program . . . .
Page
1-5
1-16
2-3
4-2
4-6
x
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SUMMARY OF RESULTS
AND CONCLUSIONS
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SECTION 1
SUMMARY OF RESULTS AND CONCLUSIONS
1.1 FUNDAMENTAL RESULTS AND CONCLUSIONS
The fundamental results and conclusions of the study of retrofit method effectiveness
and costs are summarized as follows:
« Retrofit Emission Reductions and Costs - Retrofit devices which are
designed to control emissions from gasoline-powered light duty
vehicles can be classified according to the following sources of
vehicle emissions they control:
a. Crankcase Blowby Emission Control Systems
b. Fuel Evaporative Emission Control Systems
c. Exhaust Gas Emission Control Systems
It has been estimated that reliable crankcase blowby control systems
can reduce up to 20 percent of all the hydrocarbons emitted by cars
without any emission controls. Twenty-three percent of the current
national car population do not have controls for crankcase emissions.
Feasible retrofit crankcase blowby control systems are currently
available. The conventional types cost up to $40 installed.
It has also been estimated that reliable evaporative control devices
could reduce all the hydrocarbons emitted from an uncontrolled car
as much as 20 percent. About 85 percent of the current total car
population do not have evaporative controls. There were no retrofit
fuel evaporative emission control devices for used vehicles at the
time of this study. However, on the basis of the systems being
supplied on new vehicles, it was estimated that a used car retrofit
evaporative control could cost as much as $140.
Exhaust gas emissions account for about 60 percent of the hydrocarbon
emissions, essentially 100 percent of the carbon monoxide, and 100
percent of the oxides of nitrogen from an uncontrolled vehicle.
A group of 11 retrofit exhaust devices was selected for testing in
the retrofit program. Four of these devices received up to 18 tests.
The emission reductions with 90 percent confidence limits of the mean
reduction for these four representative retrofit exhaust emission
control systems are presented in the following table:
1-1
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DEVICE NUMBER
AND
DESCRIPTION
Manifold
96 Catalytic Converter with
Distributor Vacuum
Advance Disconnect
175 Ignition Timing Modifica-
tion with Lean Idle
Adjustment
246 Speed-Controlled Exhaust
Gas Recirculation with
Distributor Vacuum
Advance Disconnect
PERCENT EXHAUST EMISSION REDUCTIONS (1)
HC
Pooled
Mean
.Reduction
21
68
19
12
90% Confidence
Limits of the
Mean Reduction
10 to 32
53 to 90
9 to 29
3 to 21
CO
Pooled
Mean
Reduction
58
63
46
31
90% Confidence
Limits of the
Mean Reduction
22 to 80
37 to 97
-8 to 77
6 to 60
NOx
Pooled
Mean
Reduction
-5
48
37
48
9CK Confidence
Limits of the
Mean Reduction
-15 to 5
17 to 64
27 to 47
43 to 52
(1) Exhaust tests conducted by the 1972 Federal Test Procedure.
Retrofit emission control systems include initial installation costs and
recurring costs to operate and maintain the device. Additional costs for
engine tuneup prior to device installation must also be considered if this
procedure is specified as part of the installation. The costs for engine
tuneup were excluded in the scope of this study, except for those tuneup
related parts and/or adjustments required by the retrofit device installa-
tion. The study indicated that those retrofit control systems which are
most effective generally cost more money to install and maintain. However,
the question of reasonable costs for retrofit systems ultimately depends
on the emission reduction objectives of State or air pollution control
agencies, and the options which may be available to meet those objectives.
Typical costs of retrofit systems tested in the program ranged from $21 to
$175. The catalyst system evaluated in the retrofit program reportedly
has an initial cost of $175 when installed with an air pump on an 8-cylin-
der vehicle. The ignition timing modification system and the exhaust gas
recirculation system have initial costs of $45 and $89, respectively. The
air bleed system which received 18 tests costs between $56 and $64. An-
other air bleed system evaluated reportedly costs about $23. These prices
are estimates for prototype systems based on information provided by the
retrofit developers.
Recurring costs are significantly influenced by the change in gasoline
mileage as a result of a retrofit system installation. Fuel consumption
measurements were conducted while using the 1972 Federal Exhaust Emissions
Test Procedure (which covers typical urban driving and speeds up to 57 mph).
Average penalties in fuel consumption as high as 10 percent (less miles per
gallon) and improvement as high as 7 percent (more miles per gallon) were
measured during these tests for some of the devices which received up to 18
tests. Additional testing must be undertaken to determine fuel consumption
for freeway driving and to establish the statistical significance of the data.
Catalyst systems require lead free fuels to maintain satisfactory effective-
ness over service periods of 25,000 miles. The other types of systems
tested in the retrofit program did not require special fuels.
1-2
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In addition to the fuel costs, maintenance of a retrofit device adds to
the recurring costs. Typical maintenance for air bleed systems requires
air filters to be changed every 12,000 miles. Exhaust gas recirculation
systems require cleaning, of the control valve every 6,000 miles. Catalyst
systems require a change of catalyst at 25,000-mile intervals. Electronic
ignition modification systems require no maintenance, in general, and in
most cases their repair is not possible; in the event such devices fail,
replacement with a new unit is required.
Driveability and Safety - In general, the devices that received driveabil-
ity tests in the retrofit study appeared to degrade vehicle driveability;
however, driveability was still acceptable. Average acceleration times at
wide open throttle were about 5 to 10 percent slower. High altitude (6,000-
8,000 ft) did not affect the operation of the vehicle with the retrofit in-
stalled any differently than the driveability tests conducted near sea level.
In general there were no gross safety problems due to retrofit installation.
Some of the devices appeared to have potential safety hazards, but it is
believed these could be eliminated by redesign.
Reliability - Reliability in mean-miles-before-partial and total failure
was estimated to be 50,000 service miles or more for all devices for
which sufficient data could be obtained or developed.
Installation. Inspection and Skill Level Requirements - Although the devices
evaluated did not require special tools for installation, practically all
require special equipment for low emission adjustment. In most cases, the
retrofit developer specified that the engine be well tuned prior to device
installation. To ensure low emissions, an HC and CO meter would be required
for effective retrofit device and related tuneup adjustments. The install-
ation of the devices requires normal automotive mechanical skills. However,
most auto mechanics are not presently capable of properly adjusting a retrofit
device and related engine tuneup parameters for low emissions without some
additional training. Technician upgrading through training programs would be
required for a successful and effective retrofit program.
Retrofit Device Vehicle Applicability - The retrofit systems evaluated in
this study are applicable to most pre-1968 domestic model vehicles (pre-1966
for California) not originally equipped with exhaust controls. Catalyst
systems appear to be applicable as retrofits for additional emission
reductions on 1968 and later model vehicles. Distributor vacuum advance
and exhaust gas recirculation systems may also be applicable for NOx control
of these later model-year vehicles. Air bleed systems can be easily installed
on vehicles already equipped for HC and CO control, but consideration must be
given to the possibility of over-leaning the carburetor mixture, since these
vehicles already have relatively lean carburetor mixtures. Foreign car
retrofit devices were generally not available for analysis during the program;
however, two retrofit devices were tested on a small foreign car.
Feasibility Conclusions - The study of retrofit method effectiveness and
costs performed under EPA Contract 68-04-0038 indicated that certain exhaust
emission control systems are technically feasible for retrofitting used cars.
The major consideration is one of cost. In general, the amount of money spent
for a device determines the emission reduction effectiveness to be gained.
1-3
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Some of the main problems likely to be encountered with the retrofit approach
may not be attributable to the devices. The vehicles themselves have to be
in good running condition and well tuned if retrofit devices are to be effec-
tive. Vehicle engine defects and malfunctions may degrade device performance,
and even cause device failure. Thus, the use of retrofit devices presupposes
good vehicle condition prior to device installation and good continued
maintenance.
Additional results, related to the durability of retrofit devices, will be
presented in Volume VI.
1.2 RETROFIT DEVICE CLASSIFICATION AND DESCRIPTIONS
Retrofit devices which are designed to control emissions from gasoline-powered
motor vehicles can be classified according to the sources of vehicle emissions they
control:
Group 1: Exhaust Emission Control Systems
Group 2: Crankcase Blowby Emission Control Systems
Group 3: Fuel Evaporative Emission Control Systems
Group 4: Combinations of these groups
Table 1-1 shows the detailed classification structure used to categorize retrofit
devices studied in this program.
Exhaust gas accounts for about 60 percent of the hydrocarbon (HC) emissions and
essentially 100 percent of the carbon monoxide (CO) and oxides of nitrogen (NOx)
from an uncontrolled vehicle. Crankcase blowby accounts for about 20 percent of
the HC emissions, and evaporative emissions from the fuel tank and carburetor
vents account for the remaining 20 percent of the HC emissions. Control of the
pollutants from these three sources requires devices or methods of varying com-
plexity and, correspondingly, the effectiveness of retrofit devices can vary over
a wide range. Furthermore, the addition of a retrofit control device to a used
car normally cannot be expected to be as cost effective for control of emissions
as the inclusion of control methods at the time of vehicle manufacture.
1.2.1 Exhaust Emission Control Systems
In considering the control of exhaust emissions, retrofit devices may be designed
to either work on the exhaust gases after they leave the combustion chambers and
enter into the exhaust system, or they may be designed to decrease the emission
formation by modifications to the induction system and/or the ignition and com-
bustion processes. Within these two broad categories there were several approaches
which were represented by the devices evaluated in this program.
The three automotive exhaust pollutants currently controlled by law for new light-
duty vehicles (6,000 pounds or less) are hydrocarbons (HC), carbon monoxide (CO)
and oxides of nitrogen (NOx). Smoke emissions (or particulate matter) are control-
led in some States by local ordinance, but not presently by Federal requirements.
The combination of HC and NOx in the atmosphere plus sunlight causes photochemical
reactions to occur. This, in turn, forms the reactive compounds which constitute
1-4
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smog. Carbon monoxide does not enter into the smog reaction, but in itself is a
poisonous gas.
Modification of engine operating parameters, including idle speed, air-fuel ratio
and spark timing, can affect the concentration of these exhaust gas pollutants
from uncontrolled engines. The objective of applying these modifications is to
optimize the engine operation with respect to exhaust pollutant emissions. In some
cases, those modifications which reduce HC and CO emissions tend to increase .
NOx emissions. When air-fuel ratios exceed about 15-16 to 1, NOx formation
normally decreases with additional mixture leaning. When adjustments are made
which optimize engine characteristics with respect to low emissions, vehicle drive-
ability performance parameters, such as acceleration, may be degraded.
Table 1-1. CLASSIFICATION OF RETROFIT METHODS
GROUP
TYPE
SUBTYPE
TITLE
1.1
1.2
1.3
1.4
2.1
2.2
3.1
3.2
1.1.1
1.1.2
1.1.3
1.1.4
1.1.5
1.2.1
1.2.2
1.2.3
1.2.4
1.2.5
1.2.6
1.3.1
1.3.2
1.4.1
1.4.2
1.4.3
EXHAUST EMISSION CONTROL SYSTEMS
Exhaust Gas Control Systems
Catalytic Converter
Thermal Reactor
Exhaust Gas Afterburner
Exhaust Gas Filter
Exhaust Gas Backpressure
Induction Control Systems
Air Bleed to Intake Manifold
Exhaust Gas Recirculation
Intake Manifold Modification
Carburetor Modification
Turbocharger
Fuel Injection
Ignition Control Systems
Ignition Timing Modification
Ignition Spark Modification
Fuel Modification
Alternative Fuel Conversion
Fuel Additive
Fuel Conditioner
CRANKCASE EMISSION CONTROL SYSTEMS
Closed System
Open System
EVAPORATIVE EMISSION CONTROL SYSTEMS
Crankcase Storage
Canister Storage
EMISSION CONTROL COMBINATIONS
1-5
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1.2.1.1 Exhaust Gas Control Systems
One approach for reducing HC and CO is to subject the exhaust gas to an oxidation
process. Among the retrofit devices studied, this was done by using either a cata-
lytic converter, a thermal reactor, or an afterburner.
In the catalytic converter approach (Device 96), the exhaust gas is passed through
a catalytic bed for oxidizing HC and CO to carbon dioxide (C02) and water.(1) The
catalyst is not consumed in the oxidation reaction, but deterioration may result
from use of fuels poisonous to the catalyst (such as leaded gasoline). The heat
required to initiate oxidation comes from the exhaust gas itself. The oxygen needed
for oxidation in the catalytic converter is provided either by leaning the fuel mix-
ture at the carburetor or by the addition of air into the exhaust system.
The thermal reactor works in much the same way. In the case of the rich mixture
reactor (Device 244), oxidation occurs as a result of air being pumped directly into
the exhaust manifold near the exhaust valves. At that location the exhaust gas tem-
perature is usually high enough to support oxidation of HC and CO without having to
use a catalyst, if there is enough oxygen available. With the lean reactor (Device
468), additional air is not required, since the carburetor is set at an air-fuel
mixture ratio which provides the required oxygen.
The exhaust gas afterburner (Device 308) also requires a fuel rich exhaust mixture.
The exhaust gases are oxidized by incorporating an ignition source (such as a spark
plug) in a muffler type container installed in the exhaust system.
In some designs, the catalytic, thermal, and afterburner approaches for oxidizing
exhaust gas HC and CO also indirectly reduce NOx. Frequently, a fuel rich carburetor
mixture inhibits NOx formation, mainly because of the lack of oxygen in the engine
combustion chamber. These systems, however, require air to be pumped into the exhaust
system to complete the oxidation of HC and CO.
The purpose of exhaust gas filters, such as Device 164, is to reduce or eliminate par-
ticulate emissions such as lead, carbon, or soot from the exhaust stream. There are
several approaches for removing particulates, including mechanical filtering, electric
precipitators, cyclone separators, fiberglass filters, and scrubber type devices.
1.2.1.2 Induction Control Systems
Retrofit devices of this type operate in general on the basis of either leaner air-
fuel mixture ratio or improved distribution of the mixture. Lean fuel mixtures pro-
vide HC and CO reduction by reducing the amount of fuel taking part in the combustion
process or by increasing oxygen availability. Although this same effect could be
partially accomplished by adjusting the carburetor idle circuit to a lean mixture,
some of the retrofit devices studied provide lean mixtures under all engine operating
conditions. Device 1 does this by means of a variable valve that allows air to enter
the intake manifold as a function of the manifold vacuum. Device 42 is another air-
bleed system which provides lean mixture, but in this model the effect of the air
(1) All retrofit devices were assigned an identification number. Refer to Table
4-1 of this volume for summary descriptions.
1-6
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bleed is to increase the air-fuel ratio during normal operation, not during idle or
deceleration. Device 317 combines air bleed with richened fuel intake under high
vacuum.
Device 33 provides leaner fuel mixtures by means of a carburetor modification in
which the fuel bowl is vented to the intake manifold rather than to the atmosphere
(as is the usual case). In this case, the high manifold vacuum conditions which
occur at idle and deceleration reduce the pressure differential between the bowl
and the carburetor venturi, thereby tending to decrease the amount of fuel entering
the venturi.
The intake manifold modification systems depend on improved air-fuel distribution
as a means of reducing emission levels. The intake manifold modification ap-
proaches (Devices 172, 430, and 440) use various intake manifold inserts (typically
between the manifold and carburetor) to either diffuse the air-fuel mixture or to
equalize distribution to the cylinders. Other approaches, such as carburetor
modifications to improve the air-fuel mixture diffusion in the venturi section,
were offered in the program (Device 295).
Recirculating a portion of the exhaust gases back into the induction system reduces
peak combustion chamber temperatures, and is an effective method of reducing NOx.
For example, recirculating 15-20 percent of the exhaust gas and mixing it with the
intake gases may reduce NOx up to 60-80 percent. Those exhaust gas recirculation
devices which were offered in this program also included disconnect of the
distributor vacuum advance as a method of further reducing the formation of NOx
and also enhancing the HC oxidation.
1.2.1.3 Ignition Control Systems
These retrofit types are based on two approaches to emission reduction. First
the ignition timing modification approach uses the principle of retarding the
ignition spark which increases the exhaust gas temperatures to the point where
the exhaust will continue to burn in the exhaust manifold. This is an alternate
way of accomplishing the same effect as that of the exhaust reactor systems. In
addition, the combustion cycle peak temperatures are reduced, inhibiting NOx
formation.
Second, the ignition spark modification approach is based on the concept that
improved spark ignition, either through longer spark duration (Device 259) or
higher voltage spark (Device 268) will improve combustion efficiency.
1.2.1.4 Fuel Modification
Fuel modification systems alter the normal combustion process by using different
fuels (other than gasoline) or by adding a fuel additive to gasoline. Gaseous
fuel conversion systems are designed to prolong engine life and to lower emission
levels. However, special tuning is required for lower emission levels.
Fuel additives are designed to clean up carburetor and engine deposits with mileage
accumulation or tend to keep deposit levels low when the engine and carburetor
systems are new. In this program, fuel additives were not tested, because of the
substantial mileage accumulation required to show the effect of the additive in
reducing emissions.
1-7
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1.2.2 Crankcase Blowby Emission Control Systems
Engine blowby results when the air-fuel mixture in the cylinder escapes past the
piston rings during the compression stroke. A smaller amount of the blowby leaks
past the rings during the power stroke. The blowby gases enter the crankcase and
subsequently escape to the atmosphere from an uncontrolled vehicle.
Crankcase control systems provide a means of circulating ventilation air through
the crankcase, mixing the air with the blowby gases, and recirculating the mixture
into the intake manifold through a variable or fixed orifice control valve. The flow
rate through the valve is normally controlled by intake manifold vacuum. Crankcase
ventilation air is drawn either directly from the engine compartment (referred to as
an open system), or from the engine air cleaner through a tubing into the crankcase
(a closed system).
Among the retrofit blowby control devices studied, Devices 170 and 315 are closed
systems. Devices 160 and 427 can be installed as open or closed systems. Devices
160 and 170 are currently accredited for use in California. All of these devices
are basically the same, except that Devices 160 and 427 also have filters.
1.2.3 Evaporative Emission Control Systems
These systems control fuel evaporation from the fuel tank and the carburetor. No
retrofit devices in this category were found to exist (except for the Device 165
combination system); however, a production fuel evaporative control system for new
model vehicles was evaluated for retrofit feasibility.
Gasoline tanks and carburetors are vented to the atmosphere on pre-1970 vehicles
sold new in California and on pre-1971 vehicles sold new nationally. Losses at
the carburetor occur almost entirely during the hot soak period after shutting off
a hot engine. The residual heat from the engine causes the temperature of the fuel
bowl to reach 150-200°F, resulting in substantial boiling and vaporization of the
fuel.
With high ambient temperatures (90-110°F), fuel tank temperature may increase up
to 120°F while driving or parked. During driving, the hot air from the engine flows
beneath the car and increases the fuel tank temperature. When parked over a hot
surface, fuel tank temperatures are also increased. As a result, fuel evaporation
occurs through the tank vents.
In one type of evaporative emission control system installed on 1971 and later
model vehicles, the crankcase is used as a storage container for vapors from the
fuel tank and carburetor. During the hot soak period after engine shutdown, the
declining temperature in the crankcase causes a reduction in crankcase pressure
sufficient to induct the evaporative emissions from the tank and the carburetor.
Vapors emanating from the carburetor are drawn directly to the crankcase, while
vapor from the fuel tank is first carried to a liquid-vapor separator. The liquid
condensate returns to the fuel tank and the remaining vapors are drawn into the
crankcase. When the engine is started, the crankcase is purged of the evaporative
emissions through the positive crankcase ventilation system. A sealed fuel tank
with a fill-limiting device is required to ensure that enough air is present in the
tank at all times to allow for thermal expansion of the fuel. A pressure/vacuum
relief gas tank cap is used to provide a safety valve for excess vacuum or
pressures in the fuel tank.
1-8
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In the absorption-regeneration system, a canister of activated charcoal traps the
vapors. During a hot soak period, vapor from the fuel tank is routed to a liquid-
vapor separator, and liquid fuel is returned to the tank. The remaining vapor,
along with fuel vapor from the carburetor, is vented through the canister filled
with activated charcoal that traps the fuel vapor. The vapors are purged from the
canister and drawn back into the induction system for burning in the combustion
chamber during engine operation.
A sealed fuel tank with a fill limiting device is also required in this system to
allow for thermal expansion. A pressure/vacuum relief gas tank cap is used with
this system to prevent excess vacuum or pressures in the tank.
1.2.4 Emission Control Combinations
Most of the retrofit devices evaluated combine two or more of the basic techniques
of emission control. Because of the difficulty in classifying all combinations,
the emission control combination group was reserved for those devices combining two
or more of the group level control functions; for example, exhaust with crankcase
emission control and/or with fuel evaporation emission control. Combinations with-
in a group were classified according to the major type of retrofit hardware re-
quired; thus a catalytic converter with vacuum advance disconnect was classified as
a catalytic conversion system within the exhaust gas control type, whereas an
exhaust gas recirculation system with vacuum advance disconnect was classified as
an EGR control within the induction modification type.
Under this classification system, four retrofit devices were classifiable as
emission control combinations. Device 165 combines control techniques for all
three sources of vehicle emissions. Device 408 combines exhaust gas control with
blowby control. Device 469 combines exhaust gas and particulate control. The
fourth device (Device 59) was not described by the developer other than that it
controls all exhaust emissions.
1.3 RETROFIT DEVICE PERFORMANCE
The feasibility of using retrofit devices as a means of controlling emissions from
cars that are either partly or totally uncontrolled is determined by the effec-
tiveness and the costs of the devices. Effectiveness is determined mainly by the
extent to which a device reduces vehicle emissions, and does so without causing
unacceptable drawbacks in vehicle driving quality and general operating safety.
Costs are determined by the initial purchase price of the device, including the
cost of installing it on a vehicle, plus the subsequent cost of operating and
maintaining the vehicle with the device installed. Operating and maintenance costs
1-9
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of the installed devices are calculated by the change in vehicle fuel consumption,
by the number of times it may fail partly or wholly during the vehicle's operating
life, and by the frequency and type of maintenance required, including the cost of
labor and materials.
1.3.1 Emission Reduction Effectiveness
All of the retrofit devices studied were evaluated for emission reduction effec-
tiveness in terms of their capability to reduce exhaust emissions - the source of
approximately 60 percent of vehicle HC emissions and essentially 100 percent of the
CO and NOx emissions. The exhaust emission reductions of the devices were evalu-
ated by comparing test data measured on a standard vehicle without the device in-
stalled (baseline) with test data on the same standard vehicle with the device
installed (retrofit).
The mean emission reductions of the representative devices tested in the retrofit
program are shown in Figure 1-1. These pooled mean reductions represent from 10 to
18 complete tests on each of the representative devices using the 1972 Federal Test
Procedure. (Approximately half of the tests on each device were conducted in
California and the other half were conducted in Michigan.) Figure 1-1 illustrates
the pooled mean reduction that the representative retrofit systems can achieve, and
the confidence levels for these data are shown in Figure 4-1 (see paragraphs 4.1.1.2
and 4.1.1.3).
Figure 1-1 shows that catalyst systems with vacuum advance disconnect have the
greatest potential for reducing all three exhaust pollutants (HC, CO, NOx). Air
bleed to the intake manifold systems primarily reduce CO and, to a lesser extent,
HC. The air bleed systems may show a slight increase in NOx because of the added
availability of oxygen. The ignition timing modification (spark retard) retrofit
device with lean idle adjustment is effective in reducing HC, CO and NOx. The
exhaust gas recirculation system with vacuum advance disconnect is primarily an
NOx control device, but some reduction of HC and CO is also obtained.
The results for the devices that received limited testing in the retrofit program are
presented in Sections 4 and 5. Some of the other systems which were not tested in
the retrofit program also showed substantial emission reduction. These data were
supplied either by the retrofit developer (from a recognized test laboratory) or from
tests conducted by the Environmental Protection Agency.
Thermal reactor systems with air pumps and exhaust gas recirculation showed average
reductions of 80 percent for HC, 44 percent for CO, and 65 percent for NOx. These
data are based on the EPA 9-cycle by 7-mode constant volume sampler test cycle.
A gaseous fuel (LPG) system showed an average emission reduction (based on 18 tests)
of 81 percent for HC, 85 percent for CO, and 65 percent for NOx. Gaseous fuel sys-
tems have been found to have exhaust emissions of lower photochemical smog reactivity
than gasoline systems (refer to paragraph 4.1.1.4 for additional comments on this
subject).
Because previous studies have substantiated the potential of crankcase blowby and
fuel evaporative control systems for reducing the HC associated with those emission
1-10
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100 T
90 --
80 --
O 70
UJ
ex.
to
60 --
z
O 50
40 --
^ 30
x
UJ
I20
§ 10 +
o
o
18 TESTS
CO
NOx
17 TESTS
CO
NOx
10 TESTS
NOx
15 TESTS
NOx
-10-1-
DEVICE 1
AIR BLEED
TO INTAKE
MANIFOLD
DEVICE 96
CATALYTIC
CONVERTER
WITH VACUUM
ADVANCE
DISCONNECT
DEVICE 175
IGNITION
TIMING
MODIFICATION
WITH LEAN
IDLE MIXTURE
ADJUSTMENT
DEVICE 246
EXHAUST GAS
RECIRCULATION
WITH VACUUM
ADVANCE
DISCONNECT
(See Figure 4-1 for confidence levels)
Figure 1-1. POOLED MEAN EXHAUST EMISSION REDUCTION OF DEVICES
TESTED IN THE RETROFIT PROGRAM
(ANAHEIM AND TAYLOR RESULTS COMBINED)
1-11
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sources, this aspect of the vehicle emission problem was not studied.(1) However,
devices in both categories were evaluated for their installation requirements and
costs as retrofit methods, and exhaust emission data provided by developers of
blowby devices were evaluated.
Approximately 20 percent of an uncontrolled vehicle's total hydrocarbon emission
comes from crankcase blowby. Closed blowby control systems will control all of
the HC emissions at all operating conditions and will provide air ventilation to
the crankcase. Open blowby control systems will control blowby emissions and
provide crankcase ventilation at most operating conditions. At heavy engine loads,
some blowby could escape from the crankcase through the open oil fill cap. The
quantity of escaping blowby would depend on the flow characteristics of the blowby
control valve. Since open blowby control systems are no longer legal on new cars,
they would not be likely candidates for retrofit; their operational limits are
noted to caution future evaluators who may be involved in the selection of retro-
fit devices for use.
A potential problem with combination air bleed and blowby systems is that, if im-
properly designed, they could cause excessively lean carburetion with resulting
"lean misfire" and "surge."
About 20 percent of an uncontrolled vehicle's total hydrocarbon emissions come
from the carburetor and fuel tank vents by evaporation of the fuel. Most of these
emissions occur during periods when the engine is off. No retrofit fuel evapora-
tion control system was available for evaluation as a single approach to evapora-
tive loss control. One retrofit system was a combination of exhaust, crankcase,
and fuel evaporation control, but no baseline emission data were provided by which
to calculate reductions.
1.3.2 Driveability and Safety
Information on driveability and safety was usually unavailable from retrofit device
developers, and that provided was, in most cases, unsubstantiated as to test pro-
cedure. Controlled driveability tests were conducted, however, on 11 devices
tested in the retrofit program. In general, there were no driveability character-
istics that would cause any of the devices to be considered infeasible. All of
the systems tested slightly degraded the operating characteristics of the vehicles;
however, a basic characteristic of most retrofit devices is the compromise of
(1) Representative studies that have been performed in blowby and fuel evaporative
emissions include the following:
• Rose, A. H., and R. C. Stahman, "The Role of Engine Blowby in Air Pollu-
tion," Journal of Air Pollution Control Association, Volume 11, No. 3,
pp 114-7, March 1961.
• Bennett, P. A., M. W. Jackson, C. K. Murphy, and R. A. Randall, " Reduc-
tion of Air Pollution by Control of Emission from Automotive Crankcases,"
Selected SAE Papers on Vehicle Emissions, Volume 6, pp 224-53, 1964.
• Wentworth, J. T., "Carburetor Evaporation Losses," SAE Technical Progress
Series, Vehicle Emissions, Volume 6, pp 146-156, 1964.
• Wade, D. T., "Factors Influencing Vehicle Evaporative Emissions," SAE
Paper 670126, January 1967.
1-12
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optimum driving and mileage performance to provide a degree of emission reduction.
Acceleration times at wide open throttle were generally between 5 and 10 percent
slower.
Fuel consumption variations were measured during the 1972 Federal Test Procedure for
emissions and the results of the four devices that received up to 18 tests were as
follows:
The ignition timing modification system caused an average 10 percent less miles per
gallon, and the catalyst system with distributor vacuum advance disconnect had essen-
tially no effect on gasoline mileage. The exhaust gas recirculation system with vac-
uum advance disconnect and the air-bleed-to-intake-manifold system caused an average
miles-per-gallon increase of 7 percent and 4 percent, respectively.
The exhaust gas control systems, such as catalytic and thermal reactors, were found
to be relatively free of adverse driveability characteristics. Since these devices
have to operate at high temperatures (up to 2,000°F), they have potential safety
problems unless adequately insulated.
On cars that already have lean carburetion, the air-bleed-to-intake-manifold retrofit
systems could possibly cause excessively lean carburetor mixtures which might lead to
surging and hesitation problems.
The ignition timing modification system indicated a minor adverse effect on accel-
eration, but appeared to present no additional safety or driveability problems.
1.3.3 Reliability, Maintainability, and Inspection Requirements
All retrofit devices were found to have acceptable reliability and maintainability
characteristics provided that conventional automotive design standards are applied
to production models. Almost any retrofit component designed to normal automotive
functional, cost, and production standards may be expected to exhibit a useful life
of 50,000 miles or more, provided that good maintenance habits are followed.
Most of the retrofit devices evaluated in the program have acceptable periodic
maintenance requirements. Most of these devices require 0.5 hour or less to main-
tain, and have a maintenance parts cost of $3.00 or less. Maintenance costs are
generally higher for those devices incorporating ignition timing or spark duration
as a control technique if the whole unit must be replaced when failure occurs. Only
two devices indicated maintenance requirements at less than 12,000-mile intervals.
About one-third of the devices evaluated indicated maintenance requirements only
after 25,000 or more miles. The catalyst system tested in the retrofit program re-
quires a new charge of catalyst at 25,000-mile intervals at a cost of $20 for an 8-
cylinder engine and $15 for a 6-cylinder engine.
Increased maintenance and reduced reliability imposed on the vehicle as a result of
a retrofit device was also evaluated. For example, spark retard generally increases
temperature of gases passing through exhaust valves and may induce engine overheating.
Exhaust gas recirculation may cause induction system deposit buildup. Use of cata-
lytic reactors, thermal reactors, and afterburners poses potential problems of in-
creased exhaust system backpressure and increased temperature which may cause exces-
sive valve operating temperatures. To investigate the long-term effect of some of
these operating characteristics, durability tests were performed on four representa-
tive devices. These tests will be documented in Volume VI.
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A periodic vehicle inspection program is recommended as a necessary part of any
program of vehicle emission control incorporating retrofit devices. The purpose of
this program would be to ensure that the retrofit device functions effectively after
installation as well as during its lifetime. Inspection of vehicles equipped with
retrofit devices would require measuring HC, CO, and possibly NOx levels. An emis-
sion limit would have to be established for each pollutant. For those retrofit de-
vices and systems that perform as a function of engine speed, such as the ignition
timing modification type, the desired test procedure would have to simulate differ-
ent road speeds to provide complete evaluation of the installed retrofit system. If
the exhaust control technique is independent of road-load conditions, then an idle
test may be sufficient.
Retrofit crankcase emission control systems should be subjected to an operational
check and a visual component inspection. These devices may be inspected using crank-
case vacuum or pressure as a means of establishing failure levels.
There is no information on what would be the inspection requirement for retrofit fuel
evaporative emission control systems. The pressure/vacuum safety relief systems
could be inspected with pressure gage instrumentation.
1.3.4 Initial and Recurring Costs
Initial costs consist of the material costs and labor costs necessary to complete a
retrofit installation.
Additional costs for engine tuneup prior to device installation must also be con-
sidered if this procedure is specified as part of the installation. However, be-
cause of the contract exclusion of tuneup as a retrofit method, only the tuneup
requirements directly related to the retrofit device installation were considered.
Recurring costs are those associated with retrofit repair and maintenance. Fuel
consumption increase or decrease, where it was known, was also included in this
category.
The initial costs of the more effective devices were generally higher than the less
effective devices. For example, the initial cost of the catalytic converter with
vacuum advance disconnect, which controls all three pollutants, was reported to be
$175, including an air pump. At the other extreme, the less effective air-bleed-to-
intake-manifold systems ranged from $23 to $64. For the NOx control systems, ignition
timing modification and exhaust gas recirculation, initial costs ranged from $45 to
$89.
Because the gasoline mileage factor is a sensitive factor in the amount of recurring
cost, it should be accurately determined prior to drawing final conclusions .on the
total costs of any particular retrofit method. When recurring costs were computed
in the retrofit study, the effect of fuel consumption changes were included for those
devices which were tested. This effect was excluded from the recurring cost of the
other evaluated systems because most developers did not submit fuel consumption data,
and many of those who did submit data reported improvements in economy which were
questionable.
1-14
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1.3.5 Installation Skill Level and Training Requirements
Analysis of the detailed installation and adjustment procedures for retrofit devices
showed that most retrofit system types would require a skilled automotive mechanic
to perform the installation. The principal consideration in this requirement is the
need for regulated quality control of device installation and subsequent mainten-
ance, inspection, and repair. It is essential that device installation include
emission testing to verify that the emission control effectiveness of a device is
achieved (see paragraph 4.3.3).
The physical installation of the devices evaluated requires normal automotive mech-
anic skills. However, most auto mechanics are not presently trained to properly
adjust a retrofit device and related engine tuneup parameters for low emissions.
Technician upgrading and training programs would be required for a successful and
effective retrofit program. Such training would provide certified mechanics to
operate licensed retrofit installation and maintenance centers. Further, the
training would also provide the inspectors for quality surveillance of the retrofit
program.
1.4 EVALUATION METHODOLOGY
The relative effectiveness and costs of retrofit devices were analyzed by means of
an evaluation methodology which quantitatively and qualitatively considered all
significant device performance parameters and criteria. This methodology was
structured in three general segments for evaluation. These segments were criteria,
performance, and cost effectiveness, each providing successively refined evalua-
tions. The basic evaluation criteria used in the retrofit program are listed in
Table 1-2.
The emission standards and installation cost criteria used in this study were
identical to those specified by law in California's used car standards. The used
car emission standards were applied only to the 7-mode exhaust emission test data
supplied by the developer (see Note 1 in Table 1-2). Other criteria, such as the
installation and maintenance labor rate, were developed on the basis of standards
in the automotive industry. These criteria can be adjusted by States and other
agencies responsible for vehicle emission control to meet their special require-
ments.
Results of the evaluation methodology are summarized in Section 5.
1.5 DEVELOPMENT STATUS AND APPLICABILITY
Most retrofit devices are available in at least the prototype form. At least 25
devices are either being marketed or are ready to be marketed. Some are being
marketed for purposes other than emission control, such as improved engine perform-
ance. The study indicated that several devices could become readily available
shortly after there is a clear definition of specific standards or criteria, if
these criteria are less stringent than California's.
1-15
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Table 1-2. PERFORMANCE PARAMETERS AND EVALUATION CRITERIA
FACTOR
CRITERIA
1. Emission Index Factors
a. Emission standards (1)
HC
CO
NOx
b. Emission baseline
2. Driveability and Safety Index Factors
a. Safety
b. Critical driveability
c. General driveability
3. Cost and Cost-Related Index Factors
a. Installation cost (including kit)
b. Recurring cost
c. Reliability
d. Maintainability
e. Availability
Less than 350 ppm or 4.5 gm/mi
Less than 2.07, or 47.6 gm/mi
Less than 800 ppm or 3.0 gm/mi
No increase of any pollutant beyond an allow-
able experimental error (2)
No hazardous conditions
No stall on acceleration
No hot idle stall
No backfire
Driveability Index less than 1.0 (refer to
para. 3.1.5)
Less than $85.00, including labor at $12.50
per hour (3)
Less than $15.00 per year ($0.125 per 100
miles) (4)
At least 50,000 miles of operation before
total failure
At least 12,000 miles of operation before
periodic maintenance is required
Less than 1 repair hour per 12,000 miles of
operation (4)
(1) The volume concentration values are the California used car device accreditation
standards as specified in California Health and Safety Code Chapter 4, Article 2,
paragraph 39107 (refer to Volume IV, Appendix E). These standards are for the
7-mode cold-start test cycle specified in the 1970 Federal Test Procedure (see
pertinent comments and cautions in Volume III, Section 5.1). The grams per mile
(gm/mi) correlated with the above standards were calculated for a 4,000-pound
vehicle in accordance with the method set forth in the 1970 Federal Test Pro-
cedure. If the evaluator intends to use the 1972 Federal CVS Test Procedure,
appropriate used car standards must be established for that test procedure.
(2) In this report, an experimental error of +10% was used.
(3) $12.50 per hour based on California repair labor average.
(4) Average miles driven per year assumed to be 12,000 miles.
1-16
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The retrofit evaulations conducted in this study were primarily aimed at uncontrolled
vehicles, which were not originally equipped with exhaust control devices (pre-1968
nationally and pre-1966 in California). However, some retrofit methods are applicable
to vehicles which already have partial exhaust control devices installed as original
equipment (1968 and later model-year cars nationally and 1966 and later model-year
cars in California).
Almost all of the retrofit exhaust control systems evaluated are applicable to pre-
1968 domestic vehicles with varying degrees of emission reduction effectiveness.
In general, retrofit systems are not yet available for foreign used cars.
The study showed that the catalytic converter systems might be applicable for
retrofitting all used cars. Exhaust gas recirculation systems would be applicable
to both uncontrolled and partially controlled cars. Distributor vacuum disconnect
would also be applicable to both groups of cars.
Air bleed to intake manifold systems can be easily retrofitted to both controlled
and uncontrolled vehicles. However, on vehicles which are already factory equipped
with exhaust and crankcase blowby control systems, the use of air bleed retrofit
systems may cause excessively lean carburetion that may lead to lean misfire.
In summary, it cannot be concluded that retrofit technology is directly applicable
to 1968 and later model-year.cars without further testing of individual devices.
However, some of the retrofit methods evaluated may be feasible on these cars.
Of the devices evaluated, seven have been specifically developed for used car
retrofit to the extent necessary for approval in California, the only State pres-
ently with a specified retrofit program and used car emission standards. These
devices were approved by the California Air Resources Board and are currently being
developed or produced for mass marketing in California. Device 175, the ignition
timing modification system tested in the retrofit program, was accepted in November
1971. Devices 160 and 170, crankcase blowby controls, were accepted in 1963 and 1965,
respectively. The other four (Devices 52, 459, 460, and 466) are all gaseous fuel
systems approved since 1969.
1.6 GUIDELINES FOR SELECTING AND IMPLEMENTING FEASIBLE RETROFIT METHODS
The implementation of a retrofit method of vehicle emission control must consider
the present and future requirements with respect to changing vehicle control condi-
tions, to ensure a continuous, satisfactory program. The recommended steps for
implementation are:
a. Defining the emission reductions required from the used car population.
b. Defining the characteristics of the used vehicle population to which retro-
fit methods are applicable.
c. Identifying candidate retrofit methods for application to that vehicle
population.
d. Determining which retrofit methods are most cost effective for the emission
controls to be implemented, giving due consideration to facilities and labor
requirements for implementing the retrofit program.
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e. Identifying the retrofit device certification program.
f. Conducting the cost effectiveness studies required to verify the retrofit
approach as being the most appropriate method of emission control.
g. Preparing an implementation plan.
h. Initiating and maintaining the implementation plan.
The evaluation methodology developed through this study should provide an essential
tool in the planning and implementation of optimum retrofit programs.
A retrofit device is feasible if its overall effectiveness in reducing emissions and
maintaining reasonable driving quality is sufficient to justify the costs of obtain-
ing that effectiveness. More specifically, the feasibility of a retrofit device
depends on its effectiveness and costs for particular emission control applications.
A device might appear infeasible when compared with other devices because of the
fewer number of pollutants it controls or the lesser magnitude of control it achieves.
However, it could be entirely adequate for a particular emission control situation in
which the scope and magnitude of control offered by the device is exactly what is
needed. Ultimately, therefore, retrofit device feasibility depends on the emission
control situations faced by individual air quality control regions.
In addition, the success of a retrofit program depends heavily on the availability of
the required facilities for installation and maintenance of the retrofit devices.
1.7 RECOMMENDATIONS
The following programs are recommended as future research and development efforts in
support of retrofit method implementation:
a. The applicability of retrofit methods to vehicles factory equipped with emis-
sion control techniques should be studied as a means of achieving maximum
continuity of the retrofit approach. An example of this recommendation would
be to retrofit and evaluate NOx type control devices on 1966 through 1970
model cars in California and 1968 through 1972 vehicles elsewhere in the
nation.
b. The maintenance requirements of the cost effective retrofit devices will
require that provisions for a maintenance inspection program be planned and
implemented concurrently with the promulgation of any legislation requiring
the use of retrofit devices on a mandatory basis. A study should be imple-
mented to determine the procedures, criteria, personnel, instrumentation,
facility, and training requirements of a maintenance inspection program to
support any mandatory use of retrofit devices. This program would be de-
signed to ensure that the inherent cost effectiveness of a retrofit device
is not compromised by inattention to maintenance requirements of the device.
c. Upgrading of the automotive service industry through supplemental training
programs would be required to provide correct tuneup adjustments to vehicles
with retrofit devices installed. The scope and requirements of such upgrad-
ing should be studied and specified for the principal types of devices. The
cost impact of an upgraded service industry on the cost effectiveness of
retrofit devices should also be determined.
1-18
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2 - RETROFIT PROGRAM
APPROACH
-------
SECTION 2
RETROFIT PROGRAM APPROACH
The program objective to determine what methods of emission control can be feasibly
retrofitted to light duty used cars required that the retrofit program approach be
directed toward determining the effectiveness and costs of retrofit devices. This
was accomplished by means of a comprehensive retrofit method and developer data
survey, system tests, and engineering analysis. The data survey provided informa-
tion of varying levels of completeness from all sources of available information on
retrofit methods and developers that could be identified. The system tests provided
a set of emissions, fuel consumption, and driveability test data from two widely
separated geographical areas in the U.S. for a range of representative retrofit
devices that could be tested within the schedule constraints of the program. The
engineering analysis provided system descriptions of the devices for which adequate
data were obtained through the data survey and the system tests. The results of
this analysis were combined with the emissions and other performance data to
provide quantitative inputs to the performance analysis of each retrofit method.
2.1 RETROFIT METHOD SURVEY
The retrofit program was initiated by performing a thorough search for all sources •
of information on retrofit methods and developers. The objective of the retrofit
method survey was to search all reliable sources for available information, and to
assemble as much relevant information as possible on retrofit emission control tech-
niques existing for light duty vehicles. This information survey encompassed
present and potential emission control retrofit methods applicable to pre-1972
motor vehicles in the light duty gasoline-powered class (less than 6,000 pounds
gross vehicle weight). This search was performed on an international scale. Each
potential source of information about retrofit devices being produced or manufactur-
ed was sent a letter describing the purpose of the program and requesting their
participation in the program. Each respondent expressing interest in participating
and who was an actual candidate retrofit method developer was sent a request to
provide data on his device. These data were used to screen the devices by type of
retrofit method, and to rank them based on their feasibility. The most feasible
and representative devices were selected for the retrofit test program.
The Air Pollution Control Association (APCA) Directory and the Society of Automotive
Engineers (SAE) Roster Issue were used initially to identify retrofit developer
sources. Additional source identifications were made utilizing:
Environmental Protection Agency (EPA) files
California Air Resources Board (ARE) files
Olson Laboratories Testing Services files
Inquiry to air quality agencies at Federal and State levels
A patent search conducted by the Northrop Legal Staff
A general news release.
2-1
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The approach to the retrofit method survey consisted of the following steps:
a. Identifying the sources of retrofit devices.
b. Transmitting a letter of inquiry to these sources, requesting'their partici-
pation in the program or the identification of other retrofit developer
sources. (The developer was requested to submit a letter of intent to
participate in the retrofit program.)
c. Transmitting a survey questionnaire to interested sources to obtain detailed
information about the technical and cost characteristics of their respec-
tive retrofit devices.
d. Recording of data questionnaire responses.
The data survey questionnaire was designed to obtain from the retrofit method de-
veloper the full scope and depth of information required to perform a comprehensive
system analysis and evaluation of the device submitted. The questionnaire was
structured to provide qualitative and quantitative data in the following categories:
a. System Information - Including system technical description, emission con-
trol category, development status, and vehicle adaptability.
b. Performance Data - Including emission reduction, reliability, maintaina-
bility, and driveability.
c. Cost Data - Including initial and recurring costs.
d. Marketing Plan
2.2 RETROFIT METHOD SCREENING EVALUATION
The information obtained from each retrofit developer source that responded favor-
ably was reviewed to identify the device category, level and reliability of emission
reduction, availability of device for testing, cost, and the adequacy of data by
which to perform a complete system analysis of the device. This information was
tabulated for each device to establish an overall preliminary ranking of devices.
The test candidate devices were identified on the basis of how well they represented
the generic retrofit groups, on average emission reduction potential, on development
status, on availability for testing, and on cost. Members of the OLI-Northrop-EPA
Technical Review Board then reviewed the test candidate retrofit systems and made the
selections of the devices that would receive evaluation in the test program. The
remainder of the candidate systems received an engineering analysis by a Northrop-
Olson staff of engineers from the data supplied by the retrofit developer.
Table 2-1 lists those retrofit system types which were candidates for the test pro-
gram. Crankcase blowby control devices were eliminated from test evaluations because
adequate data were already available for the engineering evaluation. Fuel additives
were also eliminated from the laboratory test evaluation because the required mile-
age accumulation to show the emission reduction effects was beyond the scheduled
time limits of the study.
Nine systems were selected for evaluation on two vehicles. After the initial selec-
tion the device manufacturers were notified. One of the selected device manufacturers
2-2
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Table 2-1. RETROFIT SYSTEM TYPES TESTED IN RETROFIT PROGRAM
DEVICE
NO. (1)
DESCRIPTION
Up to 18 Tests Per Device
1
96
175
246
Air Bleed to Intake Manifold
Catalytic Converter with Distributor Vacuum Advance
Disconnect
Ignition Timing Modification with Lean Idle Adjustment
Speed-Controlled Exhaust Gas Recirculation with
Advance Disconnect
Vacuum
Up to 3 Tests Per Device
10
33
42
69
245
288
295
Throttle-Controlled Exhaust Gas Recirculation with
Vacuum Advance Disconnect
Carburetor Modification, Main Jet Differential
Air Bleed to Intake Manifold
Electronic-Controlled Vacuum Advance Disconnect
Carburetor Lean Idle Modification
Variable Camshaft Timing
Carburetor Main Discharge Nozzle Modification
Carburetor with Variable Venturi
Pressure
and
(1) Devices evaluated are identified in Table 4-1.
declined to participate and one system was not available during the test period.
Four retrofit systems were selected to receive evaluation on 13 test vehicles. De-
tailed selection procedures and identification of the retrofit systems that were
evaluated in the test program are presented in Volume III, Section 4.
2.3 ENGINEERING ANALYSIS
The purpose of the engineering analysis of retrofit control devices was to (1) deter-
mine the acceptability of the data provided by the development sources, and (2),
when possible, develop additional or supplementary data that could be used as inputs
to the evaluation methodology. The approach for the engineering analysis was to
initiate the preparation of retrofit system descriptions from the information obtained
through the retrofit method survey and the test program. These descriptions were
used in the performance analysis. Each system description included physical,
2-3
-------
functional, and performance characteristics; driveability, maintainability, and
safety analyses; installation description; initial and recurring costs; and a feasi-
bility summary. Detailed system performance parameter analyses descriptions were
prepared by a team of engineers representing the key technologies of retrofit device
design. A discussion of the system description format and the approach to perform-
ance parameter analysis is presented in Volume III, Section 4.
2.4 TEST PROGRAM
A summary of the test vehicle fleet, test requirements, and test approach for the
retrofit test program is presented in the following subparagraphs. The detailed
test procedures are presented in Volume IV, and the test results are presented in
Volume III.
2.4.1 Test Vehicle Selection
The contract called for a maximum of 24 cars to be divided into two replicate fleets;
half in Taylor, Michigan, and half in Anaheim, California.
The rationale for the replicate fleets was to isolate retrofit system performance
differences, if any, which could possibly be attributable to driving conditions,
geographical location, and vehicle climatological exposure history at two dispar-
ate locations in the U.S., and any possible bias in testing facilities and
personnel.
Table 3-1 of Volume IV briefly describes the test fleet by model year, engine size,
and location. The California and Michigan fleets were identical in most respects.
Backup vehicles were purchased to replace some of the initial fleet in the event of
major vehicle failures.
Prior to the purchase of a test vehicle, an intensive screening inspection was con-
ducted. First, an overall vehicle inspection included a visual check of safety
related items such as tires, wheel alignment and brakes. Second, the vehicle
received an engine condition inspection. Measured blowby flow rates were compared
to the California Blowby Procedure (Volume IV, Appendix F). Cars were selected
which had normal blowby flow rates within the fourth to seventh population decile.
Cranking compression pressures were measured. If the cylinder compression pressures
measured within a range of 10 psi between cylinders, the car was acceptable. The
engine condition criterion was to accept cars which were in reasonable condition and
would not need any major engine repair throughout the test program. Hydrocarbons
and carbon monoxide emission levels were measured at idle and at 2,500 rpm (free
running). These data were used to diagnose the condition of the carburetor prior
to tuneup procedures. Ignition system malfunctions were determined with an ignition
analyzer scope. The vehicles were accepted if they met the overall vehicle and
engine condition criteria. However, carburetor and ignition system malfunctions
were not grounds for rejection.
2.4.2 Test Program Procedures
As each vehicle was procured, an "as received" exhaust emission test and a drive-
ability test were conducted. It was then tuned to the auto manufacturer's specifi-
cations to minimize the possibility of tuneup malfunction during the subsequent
retrofit system tests and to establish a reproducible baseline. The basic
objective here was to evaluate the performance of the retrofit device, not the
effect of tuneup. The vehicle then received a series of baseline (after tuneup)
2-4
-------
exhaust emission tests and driveability tests. After each baseline test, the
vehicle was equipped with the candidate retrofit system for exhaust emission
and driveability tests. The tests alternated between the baseline and retrofit
system tests until testing of all candidate systems was complete.
The 1972 Federal Test Procedure was used to measure the exhaust emissions of the
baseline and retrofit vehicles.(1) The Federal exhaust emission tests consist of
prescribed sequences of fueling, parking (cold soak), dynamometer operating condi-
tions, sampling, and analytical calculations. The exhaust test is designed to
determine hydrocarbon, carbon monoxide, and oxides of nitrogen on a mass emissions
basis while the vehicle is simulating an average urban type trip of 7.5 miles.
Following a 12-hour soak with the engine off, the test vehicle is "driven" on a
chassis dynamometer through a prescribed driving schedule. All of the exhaust gas
is collected and diluted with air, and then routed through a constant volume sampl-
ing (CVS) system. A proportional sample of the diluted exhaust emissions is collect-
ed continuously in an inert plastic bag for subsequent concentration analysis and
the analytical calculations. After the driving cycle is completed, the diluted
exhaust sample is analyzed for volumetric concentrations of hydrocarbons, carbon
monoxide, and oxides of nitrogen. Mass emission levels are then calculated using
applicable pollutant gas densities and correction factors.
Fuel consumption was measured during the baseline and retrofit exhaust emission
tests. The fuel consumed during the driving cycle was measured by weight. The
net amount of fuel consumed during the test was calculated and converted to miles
per gallon. ^
The Automobile Manufacturers Association (AMA) standard driveability test procedure
was used to evaluate the operating characteristics of the vehicle on the road
(refer to Volume IV, Appendix G). Basically, the procedure consists of a cold
start driveaway following an overnight soak period. A hot start driveaway procedure
follows the cold start driveability tests. The cold start evaluation consists of
engine startup, idle, and part throttle and full throttle acceleration modes up to
30 mph. The hot start consists of a series of cruise, acceleration, and idle
modes of operation, and hot start restart evaluations.
The quality of each driving mode was noted by the driver and recorded by an observer
during each mode of operation. Vehicle performance was determined at wide open
throttle from 0-60 mph by measuring the elapsed time. Driveability tests were also
performed to determine whether environmental extremes (such as high altitudes and
low temperatures) had any significant performance effect on vehicle driveability
when a retrofit device was installed.
The durability tests consisted of driving the retrofit device equipped cars for
25,000 miles and measuring the exhaust emissions at 5,000-mile increments. Mileage
accumulation was performed on a test route which consisted of freeway, urban, and
suburban driving at an average speed of approximately 35 mph. Fuel consumption and
driving anomalies were recorded daily.
(1) Federal Register Volume 35, Number 219, Part II, dated 10 November 1970. The
test procedure for NOx evaluation was published subsequently in Federal Register
Volume 36, No. 128, Part II, dated 2 July 1971.
2-5
-------
2.5 PERFORMANCE ANALYSIS
Data developed through the engineering analysis and system tests were utilized to
evaluate the candidate retrofit systems for their relative effectiveness and costs.
A mathematical methodology was developed to organize the many effectiveness and cost
variables for uniform and objective evaluations. This model was implemented on IBM
Model 360/65 and 370/165 computers in H-level FORTRAN. Data obtained from the sys-
tem tests and from the engineering analysis were processed through the methodology's
qualitative and quantitative analysis of each retrofit system.
The methodology itself was a beneficial byproduct of the retrofit study, and is
summarized more fully in the next section.
2-6
-------
3 - EVALUATION
METHODOLOGY
-------
SECTION 3
EVALUATION METHODOLOGY
A major objective of the retrofit study was to compare the overall performance of
the various devices relative to each other. Quantitative indexes were developed
so that an objective evaluation could be made and the devices numerically ranked.
Three principal numeric indexes - criteria, performance, and cost effectiveness -
were developed. The detailed evaluation methodology is presented in Volume III,
and is summarized below.
The evaluation methodology is structured in three equations:
a. Criteria Index: This is a qualitative index designed to provide a
gross indication of whether a particular device meets the various
legally imposed constraints such as emission reduction effective-
ness, cost, and useful life., as well as fundamental customer de-
mands such as gross safety and vehicle performance requirements.
b. Performance Index: This index quantitatively evaluates the per-
formance of the device. It is composed of the weighted sum of
an emission reduction index, a driveability index (what the device
does to the vehicle operation), and a cost index. The performance
index provides a more refined evaluation of device performance.
c. Cost Effectiveness Index: This index is the ratio of the emission
reduction index to the cost index (both are from the performance
index expression). It provides a measure of the emission reduc-
tion a given device would achieve for the money expended.
3.1 CRITERIA INDEX
The Criteria Index screens a device for a "yes" or "no" answer as to its basic fea-
sibility. The Criteria Index can be expressed as a product of terms, each of which
has a value of either 1 or 0. It provides the evaluator an indicator as to whether
a device will meet the various legislated constraints or limiting values specified
for each performance parameter.
If the Criteria Index calculation is 1, it means the device has met the legal and
implicit requirements for all criteria factors. If the Criteria Index calculation
is 0, it means the device did not pass one or more of the specified requirements.
The device is thus flagged as being substandard for at least one of the given set
of criteria used. Some of the limits, however, may be flexible to allow for cri-
teria changes due to differences in State or regional air quality control require-
ments.
3-1
-------
The Criteria Index comprises the following factors:
Emission Factors
1. Emission standards - for HC, CO, and NOx
2. Emission baseline - prevents emission increase
-— Driveability and Safety Factors
3. Safety - device affects vehicle operation and occupant safety
4. Critical driveability - stall on acceleration, idle, or backfire
5. General driveability - vehicle operation degradation due to device
installation
Cost and Cost Related Factors
6. Installation cost - initial cost of parts and labor
7. Recurring cost - incremental costs related to device upkeep following
installation
8. Reliability - mileage to partial or total failure of device
9. Maintainability - required periodic maintenance
10. Availability - time inconvenience to car owner due to device failure.
A check is easily made of the above terms to determine which one is causing a
Criteria Index of zero. A decision can then be made regarding the significance of
the problem. The Criteria Index is a gross screening process and may be used to
exclude the device from further evaluation.
Detailed definitions of the Criteria Index are presented in Section 3 of Volume III.
3.2 PERFORMANCE INDEX
The Performance Index provides a quantitative evaluation of a device. The Perform-
ance Index (PI) shows whether the emission reduction benefit of a device is rela-
tively greater than its cost and driveability penalties; and how much greater the
benefit is.
The PI is represented by a summation expression to obtain relative and quantitative
ratings of the devices under evaluation. This expression allows evaluation of a
device even if it does not pass certain State or regional evaluation criteria.
The PI expression comprises three terms, each of which is quantified by a different
unit of measure. The first term is the Emission Index. It has no dimension, since
it is expressed as a per unit reduction. The second term is the Driveability Index.
It is measured by rating points based on the driver's observation of various vehicle
operating characteristics. The third term is the Cost Index, which carries the units
of dollars per 100 miles.
3-2
-------
In order to add these individual indexes together, scaling factors (Si) have been
included to establish a common measurement scale. Weighting coefficients (C^) are
required to reflect the evaluator's choice as to the relative degree of importance
given to each index.
The overall Performance Index is expressed by the following equation:
; Emission \
Index \
Per Unit I - C
Reduction/
(DriveabilityX
Index ] - C~
Points /
(Cost \
Index
$/100 Miles/
Cj_ + C2 + C3
The Emission Index is the sum of the weighted percentage reduction of each of the
considered pollutants. Emission tests are conducted both with and without the
device installed to determine the emission reduction benefit. The Driveability
Index is determined by assessing what might be considered demerits for abnormal
driving characteristics (rough idle, detonation, surge, etc.). Again, the tests
are conducted with and without the device installed to determine the degradation in
driveability.
The Cost Index combines the initial costs of the device and the recurring costs.
Cost Index parameters are measured in terms of the retail cost of the device in
dollars, the installation cost (based on number of hours to install times the
hourly labor rate), the cost of maintenance, the cost of repair, and the cost of
operation over the estimated service life of the device.
To compute the overall Performance Index, experienced judgment must be exercised in
assigning the three weighting coefficients, C^, C2 , and C%. The coefficients given
to the Emission, Driveability, and Cost Indexes can greatly influence the relative
ranking of the devices. For example, if one were to weight driveability by a high
coefficient, as compared to a low coefficient used to weight the Emission Index and
Cost Index, a device with high driveability rating could be ranked relatively higher
than the more cost effective devices. If driveability is the evaluator's major con-
cern, then such weighting is proper. However, one must be aware of the effect that
the weighting coefficient decision can have on the relative ranking of the devices.
The rationale for establishing coefficients used in this program is discussed in
Volume III, and it is important to recognize that these values represent the best
judgment of the study personnel. The equations were designed so that the coeffi-
cients could easily be changed depending on the judgment of the specific emission
control agency using this evaluation methodology.
3.3 COST EFFECTIVENESS INDEX
The Cost Effectiveness Index (CEI) is intended to provide additional information to
complement the Performance Index. Should two or more devices have essentially
similar Performance Indexes, the one with the highest Cost Effectiveness Index would
be preferred. Cost effectiveness is usually defined as the rate of the desired
results or the desired output versus the required cost input. In this case the CEI
is defined as the ratio of the Emission Index to the Cost Index. In evaluating an
emission control device, the desired output is the per unit reduction of the
objectionable pollutant (Emission Index). The required cost input may be expressed
3-3
-------
as the total cost in terms of dollars per 100 miles driven (Cost Index). The Cost
Effectiveness Index (CEI) is expressed by the equation:
Emission Index, per unit reduction
Cost Index, $/100 miles
3.4 SENSITIVITY ANALYSIS
A sensitivity analysis of the Driveability and Cost Indexes was conducted (see
Volume III, paragraphs 6.2.2 and 6.3.4). Among all parameters measured for these
indexes, a change in fuel consumption showed the most sensitivity. To illustrate,
a 10 percent loss in fuel consumption caused by a device would increase the Cost
Index by 62 percent. A 20 percent change in the other terms of the Cost Index
would change the Cost Index by 10 percent or less. A 20 percent change in the
various Driveability Index terms could cause a Driveability Index degradation up
to 13 percent.
3-4
-------
4 - RETROFIT DEVICE
EVALUATIONS
-------
SECTION 4
RETROFIT DEVICE EVALUATIONS
Each retrofit device studied was evaluated to determine the effectiveness with which
•emissions are controlled, the influence of such control on vehicle operating perform-
ance, and total costs. This evaluation was performed on those devices for which ade-
quate information either could be obtained from the retrofit developers of the devices,
or could be developed by test and analysis within the time frame of the study. Based
on data obtained or developed in this way, it was possible to evaluate 65 devices in
varying degrees of completeness. These devices are listed in Table 4-1 by the control
number used to identify each during the study. The system description for each device
evaluated is presented in Volume II (see Appendix B). Volume V includes a list of all
known retrofit developers, each of whom was invited to participate in the program.
The effectiveness and costs of the devices evaluated are summarized in the following
paragraphs.
4.1 EMISSION REDUCTION
Eleven devices were tested using the 1972 Federal Test Procedure.(1) The average emis-
sion levels obtained for each device in these tests are listed in Table 4-2.
Use of these data in evaluating the emission reduction effectiveness of the devices has
to consider that the reliability and significance of the data depends on the type of
emission test procedure by which the data were measured and the number of tests that
were performed. As shown by Table 4-2, the type and number of tests vary considerably
among the devices evaluated. The higher the number of tests, the more reliable the
emission data are. The 1972 Federal Exhaust Emissions Test Procedure is currently the
most representative test for actual driving conditions and also the most accurate for
determining the actual amount of automotive pollution being emitted to the atmosphere.
Table 4-3 lists the same devices by related retrofit categories, based on the similar-
ity of the emission control approaches employed. Up to 18 tests were performed on one
retrofit device from each of the following representative types within the Exhaust
Emission Control Systems Group:
a. Exhaust Gas Reactors; CO and HC are oxidized to nonpolluting carbon
dioxide and water either by catalytic or thermal reaction.
b. Exhaust Gas Recirculation with Distributor Vacuum Advance Disconnect;
The recirculated gas and spark retardation decrease peak cycle tempera-
ture, thus inhibiting NOx formation. Spark retardation also produces
higher exhaust gas temperature, which results in greater HC oxidation.
(1) Refer to footnote, page 2-5.
4-1
-------
Table 4-1. DEVICES EVALUATED IN THE RETROFIT PROGRAM
DEVICE
1 (1)
(2)
10 (2)
22 (1)
23 (1)
24 (1)
31
33 (2)
36 (1)
42 (2)
52 (1)
(3)
56
57
59
62 (1)
69 (2)
93 (1)
95 (1)
DEVICE TITLE
Air Bleed to Intake Manifold: Air bleed to
intake manifold through adjustable valve open
to ambient airflow.
Throttle-Controlled Exhaust Gas Recirculation
with Vacuum Advance Disconnect: Carburetor
fuel vaporization modification, combined with
throttle-position controlled exhaust gas re-
circulation through intake manifold; and with
temperature-controlled vacuum advance dis-
connect.
Electronically reg-
Electronic modifi-
Electronic Fuel Injection:
ulated fuel injection.
Electronic Ignition Unit:
cation to coil.
Heavy Duty Positive Crankcase Control Valve
with Air Bleed: Crankcase blowby gas control
with air dilution.
Thermal Reaction by Turbine Blower Air In-
jection: Air injection into conventional
exhaust manifold by means of air turbine
operating off intake vacuum.
Carburetor Modification, Main Jet Differential
Pressure: Carburetor fuel bowl vented to in-
take manifold rather than atmosphere by means
of tubing with adjustable valve.
Fuel Conditioning by Exposure to Electromagne-
tic Field: Intake fuel routing through
magnetic field.
Air Bleed to Intake Manifold: Air bleed from
air cleaner to intake manifold through tub-
ing with adjustable valve.
LPG Conversion: Liquified petroleum gas (LPG)
conversion.
Crankcase Blowby and Idle Air Bleed Modifi-
cation: Heated air bleed through special idle
jets, combined with heated Crankcase blowby
into intake manifold.
Air Bleed with Exhaust Gas Recirculation and
Vacuum Advance Disconnect: Bleeds combina-
tion of exhaust gas and filtered ambient air
to intake manifold, with temperature-control-
led distributor vacuum advance disconnect.
Three-Stage Exhaust Gas Control System: (4)
Catalytic Converter: Replaces standard
muffler.
Electronic-Controlled Vacuum Advance Dis-
connect and Carburetor Lean Idle Modification:
Electronic control of distributor vacuum ad-
vance during idle through 1,600 rpm and dur-
ing braked deceleration with temperature-
controlled override and lean air-fuel mixture
by modifying air screws.
Catalytic Converter with Exhaust Gas Re-
circulation, Spark Modification, and Lean Idle
Mixture: Catalytic reactor with air pump and
exhaust gas recirculation, plus special igni-
tion system and lean air-fuel mixture.
Ignition Spark Modification: Fits between
spark plug leads and distributor.
PURPOSE
Lean air-fuel mixture.
Improve air-fuel diffusion, lower combustion
temperatures and increase exhaust gas oxi-
dation.
Optimize air-fuel mixing.
Enhance combustion ignition.
Recirculate unburned HC and exhaust gas from
crankcase for combustion'with lean air-fuel
mixture.
Oxidize unburned HC and CO combustion by-
products in exhaust gas.
Lean air-fuel mixture at high intake mani-
fold vacuum during idle and deceleration.
Condition fuel prior to entering carbure-
tor.
Lean air-fuel mixture
Decrease pollutants by use of lower reacti-
vity, cleaner burning gaseous fuel.
Lean air-fuel mixture in combination with
blowby control.
Lean air-fuel mixture in combination with ex-
haust gas recirculation to reduce combustion
temperature and retarded timing to increase
exhaust gas oxidation.
Combustion byproduct control in exhaust system.
Oxidize unburned combustion byproducts in
the exhaust system.
Lean air-fuel mixture combined with retard-
ed timing to increase exhaust gas oxidation.
Improve oxidation of combustion byproducts
and reduce combustion to inhibit NOx for-
mation.
Pre-condition combustion chamber gases in
preparation for ignition event.
GROUP
1.2.1
1.2.2
1.2.6
1.3.2
2.1
1.1.2
1.2.4
1.4.3
1.2.1
1.4.1
1.2.4
1.2.1
4.0
1.1.1
1.3.1
1.1.1
1.3.2
4-2
-------
Table 4-1. DEVICES EVALUATED IN THE RETROFIT PROGRAM (CONT)
DEVICE
DEVICE TITLE
PURPOSE
GROUP
96 (1)
(2)
100 (1)
160 (3)
164
165
170 (3)
172 (1)
175 (2)
(3)
182
244 (1)
245 (2)
246 (1)
(2)
259
268
279
282
Catalytic Converter with Distributor Vacuum
Advance Disconnect: Catalyst contained in
canister installed between exhaust manifold
and muffler, combined with distributor
vacuum advance disconnect, and/or air in-
jection by special pump.
exhaust gas driven turbo-
Hydrocarbon-base fuel
Turbocharger:
charger.
Closed or Open Blowby Control System with
Filter: Filtered, volumetric-controlled
blowby gas reclrculation.
Exhaust Gas Filter: Two-stage exhaust gas
filter with combined muffler function.
Exhaust Gas Afterbumer/Recirculation with
Blowby and Fuel Evaporation Recirculation:
Combined exhaust gas afterburning and re-
circulation, with crankcase blowby and fuel
evaporation.
Closed Blowby Control System: Closed blowby
gas recirculation through carburetor air
cleaner and intake manifold combination.
Intake Manifold Modification: Truncated
conical nozzles inserted between intake port
and intake manifold.
Ignition Timing Modification with Lean Idle
Adjustment: Electronically controlled igni-
tion spark retardation by sequenced regula-
tion of the distributor ignition signal and
the vacuum advance disconnect, combined with
lean idle air-fuel mixture adjustment.
Fuel and Oil Additives:
and oil additive.
Rich Thermal Reactor: Exhaust manifold re-
placement providing thermal insulated chamber
and air injection.
Variable Camshaft Timing: Cam timing gear
replacement automatically varies valve timing
from advance at idle and low rpm to retard at
high speeds.
Speed-Controlled Exhaust Gas Recirculation
with Vacuum Advance Disconnect: Exhaust gas
recirculation through intake manifold adapter
controlled by speed-sensitive solenoid valve
which also disconnects distributor vacuum
advance during low speed modes.
Photocell-Controlled Ignition System: Ignition
spark modification by photo-cell controlled
ignition system.
Capacitive Discharge Ignition: Ignition spark
modification by high-voltage capacitor dis-
charge to ignition coil primary, operating
in series to the distributor and coil.
Fuel Conditioner:
electrical field.
LP Gas Injection: Propane injection to car-
buretor air intake during acceleration and
engine load conditions, based on intake mani-
fold vacuum.
Intake fuel routing through
Oxidize unburned combustion byproducts by
catalyst action and higher exhaust tem-
perature. Reduce NOx by reduced peak
cycle combustion temperature.
Improve fuel oxidation during low intake
vacuum by forced air injection to carburetor.
Recirculate blowby gas from crankcase to
intake manifold for combustion, without
Impurities.
Incomplete data precludes full determination
of purpose; however, one application appears
to be particulate control.
Control all three major sources of vehicle
emissions.
To recirculate blowby gas from crankcase to
intake manifold for combustion.
Equalize air-fuel mixture distribution.
Spark retardation at idle and speeds below
35 mph in combination with lean air-fuel
mixture.
Reduce engine deposits and fuel consump-
tion and increase power.
Oxidize unburned combustion byproducts in
exhaust manifold.
Provide exhaust gas recirculation.
Lower combustion temperature combined with
higher temperature exhaust.
Increase spark duration and eliminate
mechanical distributor breaker points.
Modify firing voltage across the spark
plugs.
Condition fuel prior to entering carburetor.
Addition of lower reactivity, cleaner burn-
ing fuel.
1.1.1
1.2.5
2.2
1.1.4
4.0
2.1
1.2.3
1.3.1
1.4.2
1.1.2
1.2.2
1.2.2
1.3.2
1.3.2
1.4.3
1.4.2
4-3
-------
Table 4-1. DEVICES EVALUATED IN THE RETROFIT PROGRAM (CONT)
DEVICE
DEVICE TITLE
PURPOSE
GROUP
288 (2)
292 (1)
294 (1)
295 (2)
296
308
315
317
322 (1)
325
384
401
408
418 (1)
425
427
Carburetor Main Discharge Nozzle Modification:
Air jet added to main circuit nozzle outlet.
Catalytic Converter: Platinum catalyst de-
vice installed in exhaust pipe.
Exhaust Gas Recirculation with Carburetor
Modification: (4)
Carburetor with Variable Venturi:
Replacement carburetor incorporating variable
venturi and fuel nozzle.
Ignition Timing and Spark Modification:
Electronically controlled spark retardation
by delaying distributor breaker point pulse
to coil, combined with longer spark duration,
up to mid-rpm range.
Exhaust Gas Afterburner: High voltage con-
tinous-spark chamber ignites exhaust gas up-
stream of muffler in exhaust system.
Closed Blowby Control System: Crankcase
blowby recirculation through intake manifold
adapter controlled by accelerator linkage,
with air-fuel diffusion fans located in
adapter ports.
Carburetor Modification with Vacuum Advance
Disconnect: Combination air-fuel bypass from
carburetor to intake manifold, based on in-
take vacuum and valve metered flow, combined
with vacuum advance disconnect during accelera-
tion.
Exhaust Gas Backpressure Valve: Backpressure
flapper valve installed on end of exhaust
pipe.
Air-Vapor Bleed to Intake Manifold: Water-
alcohol-air-vapor bleed to intake manifold
through adapter plate with air bleed during
idle and crankcase blowby recirculation.
Air-Fuel Mixture Diffuser: Two-layer, coni-
cal wire screen air-fuel diffuser.
Air-Vapor Bleed to Intake Manifold: Metered
water-alcohol-air vapor bleed to intake mani-
fold from container.
Exhaust Gas and Blowby Recirculation with In-
take Vacuum Control and Turbulent Mixing:
Exhaust gas recirculation combined with crank-
case blowby recirculation to intake manifold
with vacuum actuated valving and turbulent
mixing.
Air Bleed to Intake Manifold: Air bleed to
intake manifold through crankcase blowby re-
circulation line.
Exhaust Gas Afterburner: Exhaust gas after-
burner operating with rich air-fuel ratio
and air injection.
Closed or Open Blowby Control System with
Filter: Closed- or open-system crankcase blow-
by recirculation to intake manifold with blow-
by filtering.
Enhance air-fuel mixture diffusion.
Oxidize emission byproducts of combustion
in the exhaust system.
Optimize air-fuel mixing combined with
lower combustion temperatures.
Optimize air-fuel ratio and diffusion.
Enhance fuel combustion and increase ex-
haust gas temperature.
Oxidize unburned byproducts of combustion
in exhaust system.
Mixing of blowby gases prior to entering
intake manifold.
Reduce combustion temperature and increase
exhaust gas temperature for improved oxida-
tion of unburned combustion byproducts.
Apply backpressure on the exhaust system.
Leaner air-fuel mixture.
Improve air-fuel mixing and conditioning
for combustion.
Leaner air-fuel mixture.
Blowby control and lower combustion
temperature.
Lean air-fuel mixture.
Oxidize unburned byproducts of combustion.
Recirculate filtered blowby gases for com-
bustion.
1.2.4
1.1.1
1.2.2
1.2.4
1.3.2
1.1.3
2.1
1.2.4
1.1.5
1.2.1
1.2.3
1.2.1
4.0
1.2.1
1.1.3
2.1/2.2
4-4
-------
Table 4-1. DEVICES EVALUATED IN THE RETROFIT PROGRAM (CONCL)
DEVICE
430
433
440
457 (1)
458 (1)
459 (1)
(3)
460 (1)
(3)
461 (1)
462 (1)
463 (1)
464 (1)
465 (1)
466 (1)
(3)
467
468
469 (1)
DEVICE TITLE
Induction Modification: Conical screen insert
between carburetor and intake manifold.
Air-Vapor Bleed to Intake Manifold: Exhaust
gas afterburner operating with lean air-fuel
ratio and air injection.
Air-Fuel Mixture Deflection Plate: Shaped de-
flection plate insert between carburetor and
intake manifold.
Water Injection: Water-alcohol-air vapor in-
jection to intake manifold.
Air Bleed to Intake Manifold: Air-vapor in-
jection to intake manifold through positive
ventilation line.
LPG Conversion with Deceleration Unit:
Liquified petroleum gas (LPG) carburetor
conversion with deceleration throttle control
device.
Compressed Natural Gas Dual-Fuel Conversion:
Dual-fuel conversion enabling use of compres-
sed natural gas or gasoline.
LPG Conversion with Exhaust Reactor Pulse Air
Injection and Exhaust Gas Recirculation :
Liquified petroleum gas conversion with
exhaust reactor, exhaust gas recycle, and
pulse air injection to reactor.
Air Bleed to Intake and Exhaust Manifolds :
Air bleed to intake manifold through crankcase
blowby recirculation line, with exhaust .
dilution by air bleed.
Rich Thermal Reactor with Exhaust Gas Recircu-
lation and Spark Retard: Replacement exhaust
manifold.
Methanol Fuel Conversion with Catalytic Con-
verter: Engine conversion for operation on
methanol fuel, combined with exhaust gas
oxidation by catalytic reaction, plus
exhaust gas recirculation option.
Fuel Additive: Bycosin fuel additive.
LPG-Gasoline Dual-Fuel Conversion: Dual-fuel
conversion enabling use of liquified petroleum
gas or gasoline.
Fuel Evaporation Control System: Fuel evapora-
tion control by carbon canister storage.
Lean Thermal Reactor with Exhaust Gas Recircula-
tion: Reactor air supplied by lean air fuel
mixture with recirculation of oxidized exhaust
gas.
Rich Thermal Reactor with Exhaust Gas Recircula-
lation and Particulate Control: Replacement
exhaust manifold (thermal reactor) with re-
circulation of oxidized exhaust gas and particu-
late trapping.
PURPOSE
To diffuse air-fuel mixture.
Oxidize unbumed byproducts of combustion.
To diffuse air-fuel mixture.
Oxidize unburned byproducts of combustion.
Oxidize unburned byproducts of combustion.
Decrease pollutants by use of lower reactivity,
cleaner burning LPG; combined with delayed
throttle closure during deceleration, to
enhance combustion of residual fuel in the
intake manifold.
Decrease pollutants by use of lower reactivity,
cleaner burning natural gas during high-
emission-potential driving modes.
Decrease pollutants by use of lower reactivity,
cleaner burning gaseous fuel combined with
oxidation of combustion byproduct.
Lean air-fuel mixture.
Oxidize combustion byproducts in the exhaust
system, while lowering combustion temperature
to inhibit NOx.
Decrease pollutants by use of lower reactiv-
ity, cleaner burning fuel and catalytic
oxidation of exhaust gas.
To enhance combustion efficiency.
Decrease pollutants by use of lower reactiv-
ity, cleaner burning natural gas during high-
emission-potential driving modes.
Control fuel evaporation from fuel tank and
carburetor.
Oxidize combustion byproducts and provide
lower combustion temperatures, plus particulate
control.
Oxidize combustion byproducts and provide
lower combustion temperatures, plus particu-
late control.
GROUP
1.2.3
1.2,1
1.2.3 '
1.4.2
1.2.1
1.4.1
1.4.1
1.4.1
1.2.1
1.1.2
1.4.1
1.4.2
1.4.1
3.0
1.1.2
4.0
(1) Previously tested by EPA.
(2) Tested in retrofit program.
(3) Accredited for use in California. In the case of Device 459, accreditation does not refer
to the deceleration control unit.
(4) System description data not available.
4-5
-------
Table 4-2. AVERAGE PERCENTAGE EXHAUST EMISSION REDUCTION BY TEST PROCEDURE
FOR DEVICES EVALUATED IN RETROFIT PROGRAM
NOTE: THE RELIABILITY OF THE DATA SHOWN DEPENDS ON THE TYPE OF TEST PROCEDURE AND NUMBER OF TESTS.
T F S
TYP
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6
ITH-
11EVIC1
DESCRIPTION
Retrofit Program Test Data
(Up to 18 Tests for Each Device) :
1
2
3
4
1
96
175
246
Air Bleed to Intake Manifold
Catalytic Converter with Distributor
Vacuum Advance Disconnect
Ignition Timing Modification with Lean
Idle Adjustment
Speed-Controlled Exhaust Gas Recircula-
tion with Vacuum Advance Disconnect
Retrofit Program Test Data
(Up to 3 Tests for Each Device):
5
6
7
8
9
10
11
10
33
42
69
245
288
295
Throttle-Controlled Exhaust Gas Recircu-
lation with Vacuum Advance Disconnect
Carburetor Modification, Main Jet Dif-
ferential Pressure
Air Bleed to Intake Manifold
Electronic-Controlled Vacuum Advance
Disconnect and Carburetor Lean Idle
Modification
Variable Camshaft Timing
Carburetor Main Discharge Nozzle
Modification
Carburetor with Variable Venturi
Developer and EPA Supplied Data:
12
13
14
15
16
17
18
19
20
21
22
23
24
23
24
52
95
' 100'
172
292
294
418
460
462
465
466
Electronic Ignition Unit
Heavy Duty Positive Crankcase Control
Valve with Air Bleed
LPG Conversion
Ignition Spark Modification
Turbocharger
Intake. Manifold Modification
Catalytic Converter
Exhaust Gas Recirculation with
Carburetor Modification
Air Bleed to Intake Manifold
Compressed Natural Gas Dual-Fuel
Conversion
Air Bleed to Intake and Exhaust
Manifolds
Fuel Additive
LPG-Gasoline Dual-Fuel Conversion
No Baseline Given for the Following Devices: (12)
25
26
27
28
29
30
1
93
459
461
463
464
468
469
Catalytic Converter with Exhaust Gas
Recirculation, Spark Modification, and
Lean Idle Mixture
LPG Conversion with Deceleration Unit
LPG Conversion with Exhaust Reactor
Pulse Air Injection and Exhaust Gas
Recirculation
Rich Thermal Reactor with Exhaust Gas
Recirculation and Spark Retard
Methanol Fuel Conversion with Catalytic
Converter
Lean Thermal Reactor with Exhaust Gas
Recirculation
Rich Thermal Reactor with Exhaust Gas
Recirculation and Particulate Control
nATA
1JA1A.
SOURCE (3
R
R
R
R
R
R
R
R
R
R
R
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
D
E
NO.
f)V
Uc
TESTS
18
17
10
15
2
2
2
3
• 1
2
1
1
(4)
18
1
1
1
1
1
(5)
1
(6)
1
6
6
1
1
3
6
5
2
AVERAGE PERCENTAGE
EMISSION
REDUCTION(l)
HC
21.0
68.4
19.2
12.1
36.7
32.9
23.2
32.4
-35.9
4.1
-36.9
2.9
3.9
81.1
-26.7
14.0
-15.0
21.2
-78.9
8.2
0.0
24.6
12.3
19.0
(7)
(7)
(7)
(7)
50.0
(7)
80.0
CO
57.8
62.6
46.3
30.9
28.7
45.8
45.3
29.2
-26.9
36.9
20.0
-16.3
12.6
85.2
-17.4
12.0
0.0
-15.4
10.4
39.4
-19.0
12.6
9.9
70.0
(7)
(7)
(7)
(7)
16.0
(7)
44.0
NOX
-4.8
47.8
37.2
47.6
53.6
-43.4
2.6
24.4
20.9
-18.7
25.4
-56.0
7.4
64.9
-31.3
8.0
27.0
41.0
30.0
1.9
-64.0
-30.0
8.2
29.0
(7)
(7)
(7)
(7)
96.0
(7)
65.0
FUEL
CONSUMPTION
pyppTT'UTAr'Tr
r HK.UC.W lALiL
CHANGE(2)
. 4
-1
-10
7
0.5
13
• 7
0
-10
' -6
-10
No data
available
4
V
No data
available
4-6
-------
Table 4-2. AVERAGE PERCENTAGE EXHAUST EMISSION REDUCTION BY TEST PROCEDURE
FOR DEVICES EVALUATED IN RETROFIT PROGRAM (CONCL)
NOTE: THE RELIABILITY OF THE DATA SHOWN DEPENDS ON THE TYPE OF TEST PROCEDURE AND NUMBER OF TESTS.
TYPE
H
<
en
Q
O
u
1
X
1
r*
u
I
H
H
X
Id
Q
S
^
Q [14
E~* H*
W C/3
if
9
1 '
ITEM
DEVICE
DESCRIPTION
7-Cycle 7-Mode Cold Start Test Procedure:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
36
57
, 59
62
164
182
244
315
317
322
384
401
425
430
458
Fuel Conditioning by Exposure to
Electromagnetic Field
Air Bleed with Exhaust Gas Recirculation
and Vacuum Advance Disconnect
Three-Stage Exhaust Gas Control System
Catalytic Converter
Exhaust Gas Filter
Fuel and Oil Additives
Rich Thermal Reactor
nATA
UAiA
SOURCE (3)
E
D
D
E
D
D
D
Closed Blowby Control System D
Carb Mod with Vac Adv Disconnect
Exhaust Gas Backpressure Valve
Air-Fuel Mixture Diffuser
Air-Vapor Bleed to Intake Manifold
Exhaust Gas Afterburner
Induction Modification
Air Bleed to Intake Manifold
No Baseline Given for the Following Devices: (12)
16
17 :
18
19
22
31
56
160
Electronic Fuel Injection
Thermal Reaction by Turbine Blower Air
Injection
Crankcase Blowby and Idle Air Bleed Mod
Closed or Open Blowby Control System
with Filter
7-Cycle 7-Mode Hot Start Test:
1
2
3
4
5
6
170
279
296
325
427
433
Closed Blowby Control System
Fuel Conditioner
Ignition Timing and Spark Modification
Air-Vapor Bleed to Intake Manifold
Closed or Open Blowby Control System
with Filter
Air-Vapor Bleed to Intake Manifold
No Baseline Given for the Following Device: (12)
7
165
Steady State
1
2
308
457
Exhaust Gas Afterburner /Recirculation
with Blowby and Fuel Evaporation
Recirculation
Exhaust Gas Afterburner
Water Injection
No Emission Data Provided by the Developer for the
Following Devices :
1
2
3
4
5
259
268
282
408
440
Photocell-Controlled Ignition System
Capacitlve Discharge Ignition
LP Gas Injection
Exhaust Gas and Blowby Recirculation
with Intake Vacuum Control and
Turbulent Mixing
Air-Fuel Mixture Deflection Plate
No Emission Evaluation was Made on the Following
Device:
6
467
Fuel Evaporation Control System
D
E
D
D
D
D
E
E
D
D
D
D
D
D
D
D
D
D
D
E '
D
D
D
D
D
(7)
NO.
f\rf
Ur
TESTS
(8)
1
1
1
1
(9)
(7)
1
3
1
1
1
1(10)
2
(ID
1
6
3
1
1
1
1
7
2
7
1
3(13)
(13)
(7)
(7)
(7)
(7)
(7)
(7)
AVERAGE PERCENTAGE
EMISSION
REDUCTION(l)
HC
-12.5
55.8
32.0
44.0
10.0
26.2
83.0
28.3
32.0
-71.3
40.2
25.0
97.0
34.0
-3.7
(7)
(7)
(7)
(7)
10.0
3.4
8.0
29.7
5.5
29.7
(7)
-17.0
0.0
(7)
(7)
(7)
(7)
(7)
(7)
CO
-0.4
52.3
18.3
14.5
2.0
30.5
67.0
28.0
22.0
6.9
19.6
34.1
97.0
9.5
7.0
(7)
(7)
(7)
(7)
-31.0
24.5
4.0
32.1
48.6
32.1
(7)
-6.3
0.0
(7)
(7)
(7)
(7)
(7)
(7)
NOX
(7)
46.6
11.0
7.0
0.1
24.0
(7)
(7)
35.0
-13.0
29.4
-31.0
(7)
36.5
-8.1
(7)
(7)
(7)
(7)'
47.0
4.3
-4.0
10.0
0.5
10.0
(7)
9.0
75(15)
(7)
(7)
(7)
(7)
(7)
(7)
FUEL
CONSUMPTION
PERCENTAGE
CHANGE(2)
No data
available
'
\
'
\
No d
t
ata
available
(1) Negative signs indicate an emission increase. (7) Unknown.
(2) Measured during 1972 Federal Test Procedure for (6) 1 baseline and 11 device tests for HC and CO only.
exhaust emissions. Negative signs indicate less (9) 4 tests for HC and CO; 1 test for NOx.
miles per gallon. (10) HC and CO measured only.
(3) Data Source: (11) 1 baseline and 2 device tests on 1 car.
R = Retrofit Test Program (12) See Volume II for emission levels with devices
D = Developer Supplied Data installed.
E = Environmental Protection Agency (13) Different steady state speeds.
(4) 6 baseline and 5 device tests for HC and CO; (14) EPA Interim 9-Cycle, 7-Mode CVS Emission Test
3 baseline and 4 device tests for NOx. Procedure (refer to Volume II, Reference 16).
(5) 16 baseline tests and 11 device tests on 3 cars. (15) NOx reduction reported for water-to-fuel ratio
(6) 10 baseline and 9 device tests for HC and CO, and of 0.9:1. No appreciable effect reported for
6 baseline and 6 device tests for NOx, on 2 cars. HC or CO.
4-7
-------
Table 4-3. AVERAGE PERCENTAGE EXHAUST EMISSION REDUCTION OF DEVICES EVALUATED
IN RETROFIT PROGRAM - LISTED BY DEVICE CLASSIFICATION (1)
NOTE: THE RELIABILITY OF THE DATA SHOWN DEPENDS ON THE TYPE OF TEST PROCEDURE AND NUMBER OF TESTS.
DEVICE
NO.
.*
DESCRIPTION
AVERAGE EMISSION
REDUCTION %
HC
CO
NOx
NO. OF
TESTS
DATA
SOURCE (2)
TEST
TYPE
GROUP 1 EXHAUST EMISSION CONTROL SYSTEMS
62
93
96
292
31
244
463
468
308
425
164
322
1
42
57
325
401
418
433
458
462
10
245
246
294
Type 1.1 Exhaust Gas Control Systems:
1.1.1 Catalytic Converter
Catalytic Converter
Catalytic Converter with Exhaust Gas
Recirculatlon, Spark Modification, and
Lean Idle Mixture
Catalytic Converter with Distributor
Vacuum Advance Disconnect
Catalytic Converter
1.1.2 Thermal Reactor
Thermal Reaction by Turbine Blower Air
Injection
Rich Thermal Reactor
Rich Thermal Reactor with Exhaust Gas
Recirculation and Spark Retard
Lean Thermal Reactor with Exhaust
Gas Recirculation
1.1.3 Exhaust Gas Afterburner
Exhaust Gas Afterburner
Exhaust Gas Afterburner
1.1.4 Exhaust Gas Filter
Exhaust Gas Filter
1.1.5 Exhaust Gas Backpressure
Exhaust Gas Backpressure Valve
Type 1.2 Induction Control Systems:
1.2.1 Air Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air Bleed with Exhaust Gas Recirculation
and Vacuum Advance Disconnect
Air-Vapor Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air-Vapor Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air Bleed to Intake and Exhaust
Manifolds
1.2.2 Exhaust Gas Recirculation
Throttle-Controlled Exhaust Gas Recir-
culation with Vacuum Advance Disconnect
Variable Camshaft Timing
Speed-Controlled Exhaust Gas Recircu-
lation with Vacuum Advance Disconnect
Exhaust Gas Recirculation with
Carburetor Modification
44.0
(9)
68.4
21.2
(9)
83.0
(9)
(9)
-17.0
97.0
10.0
-71.3
21.0
23.2
55.8
90 7
t.y • /
25.0
8.2
29.7
-3.7
24.6
36.7
-35.9
12.1
-78.9
14.5
(9)
62.6
-15.4
(9)
67.0
(9)
(9)
-6.3
97.0
2.0
6.9
57.8
45.3
52.3
1? 1
J^ . JL
34.1
39.4
32.1
7.0
12.6
28.7
-26.9
30.9
10.4
7.0
(9)
47.8
41.0
(9)
(10)
(9)
(9)
9.0
(10)
0.1
-13.0
-4.8
2.6
46.6
10 0
-31.0
1.9
10.0
-8.1
-30.0
53.6
20.9
47.6
30.0
1
6
17
1
6
(10)
3
5
3 .
1(11)
1
1
18
2
1
7
1
(12)
7
(13)
(14)
2
1
15
1
E
E
R
E
D
D
E
D
D
D
D
E
R
R
D
D
E
D
E
E
R
R
R
E
(3)
(4)
(4)
(4)
(3)
(3)
(4)
(4)
(6)
(3)
(3)
(3)
(4)
(4)
(3)
(1 \
\l )
(3)
(4)
(7)
(3)
(4)
(4)
(4)
(4)
(4)
4-8
-------
Table 4-3. AVERAGE PERCENTAGE EXHAUST EMISSION REDUCTION OF DEVICES EVALUATED
IN RETROFIT PROGRAM - LISTED BY DEVICE CLASSIFICATION (1) (CONT)
NOTEi THE RELIABILITY OF THE DATA SHOWN DEPENDS ON THE TYPE OF TEST PROCEDURE AND NUMBER OF TESTS.
DEVICE
NO.
172
384
430
440
33
56
288
295
317
100
22
69
175
23
95
259
268
296
52
459
460
461
464
466
DESCRIPTION
1.2.3 Intake Manifold Modification
Intake Manifold Modification
Air-Fuel Mixture Diffuser
Induction Modification
Air-Fuel Mixture Deflection Plate
1.2.4 Carburetor Modification
Carburetor Modification, Main Jet
Differential Pressure
Crankcase Blowby and Idle Air Bleed
Modification
Carburetor Main Discharge Nozzle
Modification
Carburetor with Variable Venturi
Carburetor Modification with Vacuum
Advance Disconnect
1.2.5 Turbocharger
Turbocharger
1.2.6 Fuel. Injection
Electronic Fuel Injection
Type 1.3 Ignition Control Systems:
1.3.1 Ignition Timing Modification
Electronic-Controlled Vacuum Advance
Disconnect and Carburetor Lean Idle
Modification
Ignition Timing Modification with Lean
Idle Adjustment
1.3.2 Ignition Spark Modification
Electronic Ignition Unit
Ignition Spark Modification
Photocell-Controlled Ignition System
Capacitive Discharge Ignition
Ignition Timing and Spark Modification
Type 1.4 Fuel Modification:
1.4.1 Alternative Fuel Conversion
LPG Conversion
LPG Conversion with Deceleration Unit
Compressed Natural Gas Dual-Fuel
Conversion
LPG Conversion with Exhaust Reactor Pulse
Air Injection and Exhaust Gas Recir-
culatlon
Methanol Fuel Conversion with Catalytic
Converter
LPG-Gasollne Dual-Fuel Conversion
AVERAGE EMISSION
REDUCTION %
HC
-15.0
40.2
34.0
(10)
32.9
(9)
4.1
-36.9
32.0
14.0
(9)
32.4
19.2
2.9
-26.7
(10)
(10)
8.0
81.1
(9)
0.0
(9)
(9)
19.0
CO
0.0
19.6
9.5
(10)
45.8
(9)
36.9
20.0
22.0
12.0
(9)
29.2
46.3
-16.3
-17 .4
(10)
(10)
4.0
NOx
27.0
29.4
36.5
(10)
-43.4
(9)
-18.7
25.4
35.0
8.0
(9)
24.4
37.2
-56.0
-31.3
(10)
(10)
-4.0
85.2 j 64.9
(9)
-19.0
(9)
| -64.0
(9) (9)
(9)
70.0
(9)
29.0
NO. OF
TESTS
1
1
2
(8)
2
3
2
1
3
1
1
3
10
1
1
(8)
(8)
1
18
1
1
1
6
6
DATA
SOURCE (2)
E
D
D
D
R
D
R
R
D
E
E
R
R
E
E
D
D
D
E
E
E
E
E
E
TEST
TYPE
(4)
(3)
(3)
(8)
(4)
(3)
(4)
(4)
(3)
(4)
(3)
(4)
(4)
(4)
(4)
(8)
(8)
(7)
(4)
(4)
(4)
(4)
(4)
(4)
4-9
-------
Table 4-3. AVERAGE PERCENTAGE EXHAUST EMISSION REDUCTION OF DEVICES EVALUATED
IN RETROFIT PROGRAM - LISTED BY DEVICE CLASSIFICATION (1) (CONCL)
NOTE: THE RELIABILITY OF THE DATA SHOWN DEPENDS ON THE TYPE OF TEST PROCEDURE AND NUMBER OF TESTS.
DEVICE
NO.
DESCRIPTION
AVERAGE EMISSION
REDUCTION %
HC
CO
NOx
NO. OF
TESTS
DATA
SOURCE(2)
TEST
TYPE
182
282
457
465
36
279
1.4.2 Fuel Additive
Fuel and Oil Additives
LP Gas Injection
Water Injection
Fuel Additive
1.4.3 Fuel Conditioner
Fuel Conditioning by Exposure'to
Electromagnetic Field
Fuel Conditioner
26.2
(10)
0.0
12.3
-12.5
3.4
30.5
(10)
0.0
9.9
-0.4
24.5
24.0
(10)
75(18)
_8.2
(8)
4.3
(15)
(8)
(6)
1
(16)
1
(3)
(8)
(6)
(4)
(3)
(7)
GROUP 2 CRANKCASE EMISSION CONTROL SYSTEMS
Type 2.1 Closed System:
24 Heavy Duty Positive Crankcase Control
Valve with Air Bleed
170 Closed Blowby Control System
I
315 Closed Blowby Control System
Type 2.2 Open System:
160 Closed or Open Blowby Control System
with Filter
427 Closed or Open Blowby Control System
with Filter
3.9
10.0
28.3
(9)
5.5
12.6
-31.0
28.0
(9)
48.6
7.4
47.0
(9)
(9)
0.5
(17)
1
1
(4)
(7)
(3)
(3)
(7)
. GROUP 3 EVAPORATIVE EMISSION CONTROL SYSTEMS
467
Fuel Evaporation Control System
(10)
(10)
(10)
(8)
(10)
(8)
GROUP 4 EMISSION CONTROL COMBINATIONS
59
165
408
469
Three-Stage Exhaust Gas Control System
Exhaust Gas Afterburner/Recirculation
with Blowby and Fuel Evaporation
Recirculation
Exhaust Gas and Blowby Recirculation
with Intake Vacuum Control and
Turbulent Mixing
Rich Thermal Reactor with Exhaust Gas
Recirculation and Particulate Control
32.0
(9)
(10)
80.0
18.3
(9)
(10)
44.0
11.0
(9)
(10)
65.0
1
1
(8)
(3)
(7)
(8)
(5)
(1) Classification of retrofit system is shown in (10)
Table 1-1. Refer to Volume II for emission (11)
levels with and without device installed on (12)
test car. (13)
(2) Data Source: (14)
R = Retrofit Test Program
D = Developer Supplied Data
E = Environmental Protection Agency (15)
(3) 7-cycle, 7-mode cold-start test procedure. (16)
(4) 1972 Federal Test Procedure.
(5) EPA 9-Cycle, 7-Mode CVS Test Procedure. (17)
(6) Different steady state speeds.
(7) 7-cycle, 7-mode hot-start test procedure. (18)
(8) No test.
(9) No baseline data reported by test source.
Unknown.
HC and CO measured only.
16 baseline tests and 11 device tests on 3 cars.
1 baseline and 2 device tests on 1 car.
10 baseline and 9 device tests for HC and CO,
and 6 baseline and 6 device tests for NOx,
on 2 cars.
4 tests for HC and CO; 1 teat for NOx.
1 baseline test and 11 device tests for HC and
CO only.
6 baseline and 5 device tests for HC and CO;
3 baseline and 4 device tests for NOx.
NOx reduction reported for water-to-fuel ratio
of 0.9:1. No appreciable effect reported for
HC or CO.
4-10
-------
c. Air Bleed to Intake Manifold; Leaner air-fuel mixture is produced,
decreasing CO, and to a lesser extent, HC, by oxidation.
d. Ignition Timing Modification; Ignition timing is retarded, by disconnect-
ing the distributor vacuum advance at low speeds, to lower combustion
temperature and NOx, with some post-combustion oxidation of HC.
4.1.1 Exhaust Emission Control Systems Group
To develop the data necessary to establish a reasonable level of confidence in the
effectiveness indicated for devices in this group, a representative device from
each of the four above types was selected for emission and driveability testing on
test vehicle fleets located in Anaheim, California, and in Taylor, Michigan.
4.1.1.1 Percentage Exhaust Emission Reduction
The emission level of the car prior to device installation was referred to as the
"baseline emissions," whereas the emission level with the device installed was the
"retrofit emissions." The effectiveness of the device in controlling the car's
emissions was then calculated for each pollutant in terms of percentage reduction.
The formula used for this calculation is:
„ , Baseline Emissions - Retrofit Emissions „ i nn
Percentage Reduction = — •— ; x iUU
Baseline Emissions
Table 4-4 shows the percentage exhaust emission reductions obtained for the devices
in these tests.
4.1.1.2 Statistical Analysis of Representative Exhaust Emission Control Device
Test Results
Two kinds of statistical testing were used on the emission reduction data of devices
tested in the retrofit program. One statistical test determined whether the
replicate results and the results from the two cities could be combined. This was
accomplished using Welch's approximate t solution for the Fisher-Behrens problem.
The Fisher-Behrens problem is the testing of the hypothesis that the means of two
normal populations are equal regardless of the size of their respective variances
based on two samples, one drawn from each population. A brief description and a
sample calculation of Welch's approximate solution of the Fisher-Behrens problem is
presented in Volume III, Appendix H.(1)
The second statistical test considered whether the percentage emission reduction was
different than zero for results of a given location or for location data combinations.
This test used a normal student t test. Two sided 90 percent confidence limits were
calculated for the mean percentage emission reductions.
(1)welch, B. L., Biometrika 34, 28-35, January 1947.
4-11
-------
Table 4-4. PERCENTAGE EXHAUST EMISSION REDUCTION OF DEVICES TESTED
IN RETROFIT PROGRAM
CAR NO. AND
LOCATION (1) MAKE AND CID
Device 1: Air Bleed to Intake
Manifold
Anaheim
1 65 Chev 194
2 65 Ford 289
3 65 Ply 318
4 65 Chev 327
5 65 Ford 390
6 61 Chev 283
17 65 Ford 390
18 61 Chev 283
19 65 VW 92
Taylor
8 65 Ford 289
9 65 Ply 318
10 65 Chev 327
11 65 Ford 390
12 61 Chev 283
16 65 Chev 327
20 65 VW 92
Device 96: Catalytic Converter
with Vacuum Advance Disconnect
Anaheim
1 65 Chev 194
2 65 Ford 289
3 65 Ply 318
4 65 Chev 327
5 " 65 Ford 390
6 61 Chev 283
Taylor
8 65 Ford 289
9 65 Ply 318
10 65 Chev 327
11 65 Ford 390
12 61 Chev 283
Device 246: Speed-Controlled
Exhaust Gas Recirculation with
Vacuum Advance Disconnect
Anaheim
1 65 Chev 194
2 65 Ford 289
3 65 Ply 318
4 65 Chev 327
17 65 Ford 390
18 61 Chev 283
19 65 VW 92
TEST 1
HC
17.7
30.5
-8.2
4.8
20.8
(3)
46.4
41.0
26.5
-29.0
23.6
46.0
71.2
85.1(4)
92.2(4)
34.1
86.7(4)
40.6
68.1(4)
66.6
85.3
70.8
92.9(4)
86.2(4)
(3)
27.6
-13.7
2.8
0.9
(3)
15.4
CO
-6.3
31.4
60.6
46.4
41.4
36.1
56.9
89.3
79.3
93.1
74.0
50.4
85.5
78.3
95.1
12.1
99.2
24.1
32.9
67.4
83.2
77.6
99.5
95.8
12.4
33.7
32.9
23.4
10.3
-8.3
11.6
NOx
-50.5
-10.6
16.6
14.6
0.0
12.7
12.4
24.9
13.9
-0.3
-28.4
3.6
6.9
76.7
65.0
68.8
38.0
66.3
34.6
51.7
58.1
61.7
57.6
50.0
60.0
37.4
54.5
36.9
58.5
44.5
26.1
TEST 2
HC
(2)
3.1
6.9
2.8
51.6
1.9
51.6(4)
75.6(4)
65.9(4)
75.1(4)
38.4
48.7
CO
77.9
34.7
73.1
63.2
52.6
77.4
63.2
51.2
76.6
26.9
4.1
NOx
-17.4
24.8
-18.8
-57.5
-33.1
15.7
41.1
30.2
56.6
28.1
11.6
4-12
-------
Table 4-4. PERCENTAGE EXHAUST EMISSION REDUCTION OF DEVICES TESTED
IN RETROFIT PROGRAM (CONT)
CAR NO. AND
LOCATION (1) MAKE AND CID
Taylor
8 65 Ford 289
9 65 Ply 318
10 65 Chev 327
11 65 Ford 390
12 61 Chev 283
20 65 VW 92
Device 175: Ignition Timing
Modification with Lean Idle
Adjustment
Anaheim
1 65 Chev 194
3 65 Ply 318
4 65 Chev 327
5 65 Ford 390
6 61 Chev 283
Taylor
8 65 Ford 289
9 65 Ply 318
10 65 Chev 327
11 65 Ford 390
12 61 Chev 283
16 65 Chev 327
Device 10: Throttle-Controlled
Exhaust Gas Recirculation with
Vacuum Advance Disconnect
Anaheim
4 65 Chev 327
6 61 Chev 283
Device 33: Carburetor Main Jet
Differential Pressure Modifica-
tion
2 65 Ford 289
4 65 Chev 327
Device 42: Air Bleed to In-
take Manifold
4 65 Chev 327
5 65 Ford 390
TEST 1
HC
(3)
8.3
(3)
18.0
9.9
9.4
14.1
33.1
4.8
-21.0
(3)
16.8
26.5
19.0
24.5
33.7
40.0
45.9
27.5
52.7
13.0
-7,6
54.0
CO
(3)
58.4
(3)
31.4
30.1
-26.6
11.4
21.5
8.1
-9.8
(3)
76.5
78.7
61.1
74.7
67.0
73.4
39.0
18.3
62.8
28.7
50.0
40.9
NOx
(3)
47.6
(3)
44.7
40.9
(3)
43.6
43.0
14.9
35.2
(3)
56.6
42.5
56.5
3.0
34.4
42.8
55.5
51.6
-121.6
34.9
-3.1
8.3
TEST 2
HC
-11.1
-5.0
18.3
46.0
40.2
CO
-4.2
60.8
45.4
72.8
53.4
NOx
57.7
58.1
55.8
49.3
41.4
4-13
-------
Table 4-4. PERCENTAGE EXHAUST EMISSION REDUCTION OF DEVICES TESTED
IN RETROFIT PROGRAM (CONCL)
CAR NO. AND
LOCATION (1) MAKE AND CID
Device 69: Electronic-
Controlled Vacuum Advance
Disconnect and Carburetor Lean
Idle Modification
Anaheim
3 65 Ply 318
4 65 Chev 327
5 65 Ford 390
Device 245: Variable Camshaft
Timing
6 61 Chev 283
Device 288: Carburetor Main
Discharge Nozzle Modification
2 65 Ford 289
6 61 Chev 283
Device 295: Carburetor with
Variable Venturi
5 65 Ford 390
TEST 1
HC
39.2
27.5
30.6
-35.9
6.2
2.0
-36.9
CO
30.1
37.6
20.0
-26.9
38.9
34.8
20.0
NOx
32.1
-5.6
46.7
20.9
-1.8
-35.6
25.4
TEST 2
HC
CO
NOx
(1) Positive percentage denotes emission reduction from baseline and negative percentage
denotes emission increase from baseline.
(2) All blank spaces and columns denote that no tests were performed, except for Note (3).
(3) Measured test data were invalid.
(4) Air pump installed and operating.
Although the absolute magnitude of the percentage reduction is subject to considerable
error due to the small sample size of the retrofit test program, the mean values
still represent the best known estimate of the true values. The statistical data
provided by this analysis are shown in Table 4-5. A discussion of the emission
reduction statistical confidence limits is presented in Volume III, paragraph 6.1.
4.1.1.3 Statistical Analysis Conclusions
Figure 4-1 shows the 90 percent confidence limits calculated for the emission
reduction effectiveness of the four representative devices.
Device 96, the catalytic converter with distributor vacuum advance disconnect,
shows a large percentage reduction for all three pollutants.
4-14
-------
Device 175, the ignition timing modification system with lean idle mixture
adjustment (which has been accredited by California for retrofit installation on
1955-65 model year cars), was effective for NOx control, with mean reduction
levels centering on the 37 percent reduction level. The HC mean reduction level
of this device was also statistically significant.
Since Device 175 is an ignition timing modification with lean carburetor idle
mixture by adjustment, it is not likely that this device controls the overall CO
during a CVS test to a significant degree. It is known that lean idle mixture will
reduce the overall CO level to some extent, but not to the extent shown in the
Taylor data (an average of 72 percent). By comparison, the Anaheim data showed a
mean CO reduction of 8 percent. This CO reduction may be more representative for
this device.
Table 4-5. MEAN PERCENTAGE EMISSION REDUCTION AND 90 PERCENT CONFIDENCE INTERVALS
FOR EXHAUST EMISSION CONTROL RETROFIT SYSTEMS TESTED AT
ANAHEIM, CALIFORNIA AND TAYLOR, MICHIGAN (1) (2)
Hydrocarbon Reduction (%)
Test Data
Combination
Mean
(n)
90%
Confidence
Limits
Carbon Monoxide Reduction (7.)
Test Data(3)
Combination
Mean
(n)
90%
Confidence
Limits
Oxides of Nitrogen Reduction (%)
Test Data(3)
Combination
Mean
(n)
90%
Confidence
Limits
Device 1: AIR BLEED TO INTAKE MANIFOLD
WT2
21.0(17)
10.4 to 31.6
Al
VT2
38.1(7)
70.3(11)
2l'.8 to 54.4
60.4 to 80.2
A1+T1+T2
-4.8(18)
-14.9 to 5.4
Device 96: CATALYTIC CONVERTER WITH VACUUM ADVANCE DISCONNECT
VA2
Tl
63.5(12)
80.4(5)
53.0 to 74.0
69.7 to 91.0
A1+A2
Tl
53.4(12)
84.7(5)
36.5 to 70.4
72.1 to 97.3
VT1
A2
57.1(11)
30.6(6)
50.2 to 64.1
16.9 to 44.2
Device 175: IGNITION TIMING MODIFICATION WITH LEAN IDLE ADJUSTMENT
VT1
19.2(10)
8.9 to 29.3
Al
' Tl
7.8(4)
71.9(6)
-7.6 to 23.1
66.5 to 77.3
A1+T1
37.3(10)
27.5 to 47.0
Device 246: SPEED-CONTROLLED EXHAUST GAS RECIRCULATION AND VACUUM ADVANCE DISCONNECT
VT1+T2
12.1(13)
3.1 to 21.1
T1+T2
Al
43.5(8)
16.6(1)
27.3 to 59.7
5.7 to 27.4
VT1+T2
47.6(15.)
43.1 to 52.1
Negative reductions indicate an emission level increase from baseline
(2)
Confidence intervals calculated from data presented in Table 6-1 (Volume III)
AI = Anaheim Test 1 TI = Taylor Test 1
A2 = Anaheim Test 2 T2 = Taylor Test 2
(4)
A]^+T^+T2 means that Anaheim Test 1, Taylor Tests 1 and 2 reduction data were combined as a single
sample. See Volume III, Appendix H, for explanation of test data combinations as determined by
Welch's approximate t solution of the Fisher-Behrens problem. (X) indicates total number of tests.
4-15
-------
Device 246:
Device 175:
Device 1: Device 96: Ignition Timing
. Air Bleed to Catalytic Converter with Modification with Lean
Intake Manifold Vacuum Advance Disconnect Idle Adjustment
l ii ii i
100 r C0
g SO
±J
U
1 «o
cC
O
« ' 40
B
- I'ercent En
N>
0 0
-20
HC —
co HC M ~ co
H M I~~| NOX LJ
n\_l M r~i
co I LJ
r~i L- J — U NOX
U n P
«C ^ HC h
B u Q Bn
NOX ' — 1 —
U
AI A^ TI AI A^ Ti Ai Ti A^ A2 AI A]^ Tj A^
Test
Combinations Ti T2 Ti AT A2 Ti Ti T,
(2)
T2 T2
Speed-Controlled
Exhaust Gas
lation with
Reclrcu-
Vacuum
Advance Disconnect
'
B
AI
TI
T2
CO
0
CO
^
" ll
NOx
B
AI
T.
T2
-, 100
-
-
-
-
80 g
f4
4J
3
60 -J
tf
o
40 ^
0)
M
0 0
Percent En
-20
A. = Anaheim Test 1
T^ = Taylor Test 1
T. = Taylor Test 2
(1) Data are from Table 4-5.
(2) See Volume III, Appendix H for explanation of
Statistical Test Combinations.
Upper 907. Confidence Limit
Mean Emission Reduction
Lower 907. Confidence Limit
Figure 4-1. PERCENTAGE EXHAUST EMISSION REDUCTION MEANS AND 90% CONFIDENCE
LIMITS FOR EXHAUST EMISSION CONTROL RETROFIT SYSTEMS TESTED AT
ANAHEIM, CALIFORNIA, AND TAYLOR, MICHIGAN (1) :
Device 246, the exhaust gas recirculation and vacuum disconnect system, is clearly an
NOx control device. The CO reduction is also considerable with a pooled mean level
of 31 percent for the Anaheim and Taylor test results. The HC reduction pooled mean
was 12 percent.
Device 1, an air bleed to intake manifold type, is clearly a CO control device. The
HC percentage reduction is also significantly different than zero to a lesser degree.
The air bleed system does not control NOx, as its principle of operation leans the
overall air-fuel mixture and lean mixtures generally will increase the NOx emission
levels because of the availability of additional oxygen.
4.1.1.4 Screening and Developer Exhaust Emission Test Results
Table 4-2 identifies the retrofit devices that received up to three tests in the
retrofit program, and the devices for which the developers provided test data.
4-16
-------
The significant comparisons with devices tested on a vehicle basis are highlighted
below for those devices with comparable types and numbers of tests.
Device 10, an exhaust gas recirculation system with vacuum advance disconnect, showed
essentially the same CO and NOx emission reduction effectiveness as its fleet tested
counterpart, Device 246.
In the air-bleed-to-intake-manifold category, Device 42 was directly analogous to
Device 1 as a significant CO reducer, with some HC reduction effectiveness. Device
401, which also acts as an air bleed to the intake manifold, showed equivalent
emission control characteristics,, Device 325, an air-bleed-to-intake-manifold
system with crankcase blowby recirculation, showed reductions equivalent to the air
bleed systems evaluated in the test program (HC and CO reductions with essentially
no change in NOx). Device 33, a carburetor main nozzle modification, showed
significant emission reduction for HC and CO, but NOx increased 43 percent.
Device 69 followed the pattern of Device 175, as an ignition timing modification with
lean idle mixture adjustment, in providing HC, CO, and NOx reduction.
Device 469, a rich thermal reactor combined with exhaust gas recirculation, showed
equivalent emission reductions to the catalyst system (Device 96) tested on the vehicle
fleet, with substantial reductions for all three exhaust pollutants.
Device 52 is representative of the gaseous fuel systems. The high air-fuel ratios
which these systems enable make reductions of all three exhaust pollutants possible.
It is generally agreed that HC emissions from gaseous fueled vehicles have less
photochemical smog reactivity than those from gasoline fueled vehicles. No Federal
reactivity scale has been defined to allow for quantitative correction of this
difference between fuels. In California, a reactivity factor is being used in the
test procedure for gaseous fuel system conversions.(1)
4.1.2 Crankcase Emission Control Systems Group
Crankcase control systems could reduce total vehicle HC emissions up to approximately
20 percent from an uncontrolled vehicle. (2) This type of retrofit device may indirectly
affect exhaust emissions. This characteristic could be caused by the flow charac-
teristics of the system. If the total flow of a blowby control system far exceeds the
blowby flow rate produced by the engine, then it becomes a mixture leaning device,
such as an air-bleed-to-intake-mariifold system. The device still has an advantage
over the air bleed in that crankcase blowby is being controlled and the crankcase is
being purged with ventilation air»
No retrofit devices were tested in this group, since considerable data already exist
on these devices, which have been in use on new cars in California since 1961 and
nationally since 1963. Exhaust emission data were obtained on five devices in this
category (Table 4-3).
(1) "California Exhaust Emission Standards and Test Procedures for Motor Vehicles
Modified to Use Liquid Petroleum Gas or Natural Gas Fuel," State of California
Air Resources Board, 28 November 1969.
(2) "Control Techniques for Carbon Monoxide, Nitrogen Oxide, and Hydrocarbon Emis-
sions from Mobile Sources," National Air Pollution Control Administration Publi-
cation No. AP-66, March 1970.
4-17
-------
A potential problem could result from use of the air-bleed retrofit systems in com-
bination with positive crankcase ventilation (PCV) and exhaust gas recirculation
systems; this may cause excessively lean air-fuel carburetion. This could result
from a combination of high ventilation airflow rates through the PCV valve and/or
the additional air provided by an air-bleed system installed between the PCV valve
and the intake manifold. High crankcase ventilation airflow rates occur on PCV
equipped vehicles with low blowby flow rates. As the vehicle accumulates mileage
blowby flow rates generally increase and ventilation airflow of the PCV system de-
creases. The possibility of excessive air ventilation decreases with age.
On the other hand, if an older used vehicle with a PCV system has a relatively rich
fuel mixture, an air-bleed retrofit system could show some HC and CO emission
reduction, provided that the air-bleed device flow rate is not excessive. In using
the air-bleed approach for HC and CO control, criteria would have to be established
to identify "lean" and "rich" cars and the allowable carburetor air-fuel mixture
changes caused by the air-bleed system. Additional considerations on retrofit de-
vice vehicle applicability are presented in Section 6.
4.1.3 Fuel Evaporative Emission Control System Group
Carburetor and fuel tank evaporative emission control systems could reduce total
vehicle hydrocarbon emission up to 20 percent from an uncontrolled vehicle. Without
evaporative loss control, as much as 29 grams of fuel can evaporate during the hot
soak period following shutdown of a hot engine. This type of system, like the blow-
by controls, may indirectly affect exhaust emissions.(1)
No evaporative control devices were found to be available for retrofit use or under
development other than Device 165, a combination emission .control system which in-
corporates gas tank and crankcase vapor controls.
Use of fuel evaporation emission control systems was initiated in 1970 on new motor
vehicles sold in California and in 1971 on new vehicles sold nationally. Two fuel
evaporative systems have been designed for production use. These are based on two
different approaches to fuel vapor recovery. One system stores the fuel vapor in
the crankcase and the other stores the vapor in a carbon canister during soaking
periods (engine off). The vapors are purged from the crankcase or canister when
the engine is running. The effectiveness of either system for reducing overall
vehicle emissions should be equivalent.
4.2 DRIVEABILITY AND SAFETY
The driveability and safety of retrofit devices were evaluated as related factors
in a device's overall effectiveness, because many driveability problems may also
be safety problems.
(1) Deeter, W.F., H.D. Daigh, and O.W. Wallin, Jr., "An Approach for Controlling
Vehicle Emissions," SAE Paper 680400, May 1968.
4-18
-------
4.2.1 Exhaust Emissions Control System Group
All of the devices tested belonged to the exhaust control retrofit group. The
driveability tests were performed in accordance with the test procedures of the
Automobile Manufacturers Association (AMA). These procedures include both cold
and hot driving modes for determining the number of times required to start the
vehicle, cranking time per start, rough idle, stall at idle, stall at various speed
increments, backfire, detonation, surge, stretchiness, hesitation, and acceleration.
These driveability characteristics were divided into two categories, critical and
general; the former consisted of backfire and stall under both hot and cold driving
modes, and the latter consisted of all other parameters. Backfire and stall were
considered critical characteristics because of their possible adverse effect on the
driver's safety and the vehicle's functional integrity. Each characteristic was
measured in terms of either no problem; or trace, moderate, or heavy problems. Fuel
consumption, measured during the emission tests, was an additional factor analyzed
for impact on driveability and also was an input to the cost calculations.
Driveability characteristics were determined for the test vehicles with and without
the retrofit devices installed. Additional tests were performed on four devices,
including mountain, desert, and urban driving, to determine the effects of operating
extremes on vehicle driveability with the devices installed. In the quantitative
calculation of the driveability performance or index of a device, if there was no
change in the driveability parameters with the retrofit device installed, as compared
to the same vehicle without the device, the general Driveability Index was equal to
zero. This was the best case (unless driveability was improved by the retrofit
device), since the Driveability Index was calculated as a penalty index. For
example, should an acceleration loss of three seconds be the only consequence of
device installation the index would equal 1.25. This high of an index exceeds the
acceptable limit level of 1.0 shown in the evaluation criteria of Table 1-2.
Test and analysis of the retrofit devices for their effect on safety was based on
such factors as exhaust gas leakage, leakage of raw fuel, introduction of raw fuel
to a source of ignition, engine failure or loss of power, and introduction of
temperatures excessive for human or vehicle safety.
Table 4-6 presents the driveability results for the 11 devices tested. The general
driveability and safety characteristics of the representative devices that
received up to 18 tests are summarized in this table:
a. Air Bleed to Intake Manifold Devices: These devices have to be carefully
tuned as part of the engine system, since they affect the air-fuel
mixture. Too lean a mixture can cause rough idle, hesitation, surge, and
slower acceleration. In the devices evaluated, traces of these problems
were evident.
There were no safety problems identified for the air bleed devices.
Gasoline mileage improved 4 percent, while acceleration times were
10 percent slower on the average.
4-19
-------
Table 4-6. DRIVEABILITY AND SAFETY CHARACTERISTICS FOR DEVICES
TESTED IN RETROFIT PROGRAM
DEVICE
NO.
1
96
175
246
10
33
42
69
245
288
295
DESCRIPTION
Air Bleed to Intake
Manifold
Catalytic Converter with
Distributor Vacuum
Advance Disconnect
Ignition Timing Modifica-
tion with Lean Idle
Adjustment
Speed-Controlled Exhaust
Gas Reclrculation with
Vacuum Advance Disconnect
Throttle-Controlled Exhaust
Vacuum Advance Disconnect
Carburetor Modification,
Main Jet Differential
Pressure
Air Bleed to Intake
Manifold
Electronic- Controlled
Vacuum Advance Discon-
Lean Idle Modification
Variable Camshaft
Timing
Carburetor Main Discharge
Nozzle Modification
AVERAGE
DRIVEABILITY
INDEX
0.138
0.304
0.118
0.113
0.441
0.181
0.116
0.087
0.895
-0.459
3.261(7)
NO. OF
TESTS
18
17
10
13
2
2
2
3
1
1
1
CRITICAL
DRIVEABILITY
CHARACTERISTICS (1)
Less tendency to stall
during cold start accel.
modes (No. of occurrences
Insignificant)
More stalls during cold
leant)
More stalls during cold
start acceleration modes
Insignificant)
No effect
No effect
No effect
More stalls during cold
start acceleration modes
significant; based on
2 tests only)
More stalls during cold
(No. of occurrences
insignificant)
No effect'
No effect
More stalls during cold
(No. of occurrences
significant; based on
one test only)
GENERAL
DRIVEABILITY
CHARACTERISTICS (1)
More stall at Idle and
acceleration hesita-
tion during cpld modes
• Longer starting
times; more hesita-
tion, and stretch-
start modes
• Idle was Improved
during cold and hot
start modes
modes
More stumble and
hesitation during
cold start modes
'• More stumble, hesi-
tation during cold
start modes
• Increased accelera-
tion times
• More stumble and
cold start modes
• Longer starting
times during hot
start modes
Longer starting times
during hot start
• Worse idle per-
formance during
cold start modes
• Longer starting
times during hot
start modes
• Less detonation
during hot start
modes
More hestiation
modes
More stretchiness
during cold start
modes
Shorter starting
times and less
stumble during
cold start modes
• Longer starting
at idle during
cold arart modes
• More hesitation
during hot start
modes
• Shorter starting
times during hot
start modes
SAFETY
HAZARDS
None
Potential
fire
hazard (4)
None
None ( 5)
None (5)
Possible
fire
hazard (6)
None
None
None
None
None
AVERAGE CHANGE, %
0-60
ACCEL(2)
-10
-5
-6
-6
-19
-5
-3
-2
-38
17
-12
GASOLINE
MILEAGE (3)
4
-1
-10
7
0.5
13
7
0
-10
-6(8)
-10
(1) Comments describe vehicle operation with device installed as compared to standard vehicle without device.
(2) Negative signs indicate acceleration degradation.
(3) Negative signs indicate less miles per gallon during 1972 Test Procedure emission test.
See Appendix L, Volume III for fuel consumption.
(4) Potential fire hazard due to excessively high converter temperatures.
(5) Assumes good maintenance is practiced to prevent recirculated exhaust leakage.
(6) Potential fire hazard due to raw fuel syphoning to intake manifold.
(7) It is possible that this DI Is invalid due to an inadvertent maladjustment of the ignition timing.
(8) Based on two measurements performed during emission tests using the 1972 Federal Test Procedure. Only one drlveablllty test was valid.
4-20
-------
b. Exhaust Gas Reactor Devices: The catalyst device evaluated in the retrofit
program required no-lead fuel. Detonation was evident in some of the test
vehicles. Acceleration times were about 5 percent slower with the
device installed. Gasoline mileage decreased 1 percent on the average.
For safety considerations these devices have to be insulated or located
such that their inherently high operating temperatures cannot injure
operating or maintenance personnel, or cause thermal damage to vehicle
structure and components.
c. Ignition Timing Modification: Electronic or mechanical control of
ignition timing to retard the spark caused slower acceleration times of
6 percent. Gasoline mileage with these devices decreased by as much
as 10 percent (Device 175).
These devices are characteristically only operative at idle and low- to
mid-rpm ranges, where emissions are greatest and, therefore, do not affect
normal cruising driveability. Some stumble and hesitation was observed
during the cold start modes of operation.
There appear to be no safety problems, provided that all components are
maintained satisfactorily.
d. Devices Incorporating Exhaust Gas Recirculation with Distributor Vacuum
Advance Disconnect: Recirculated exhaust gas affects driveability
slightly, because of the dilution it causes in the air-fuel mixture.
When combined with retarded spark, as in the case of Device 246, this
dilution caused acceleration times to be 6 percent slower. Gas mileage
was improved by 7 percent on the average for Device 246.
No safety problems were evident in the devices examined; however, good
maintenance would have to be practiced to ensure that the recirculated
exhaust gas does not leak into the engine or passenger compartments and
thereby introduce a safety problem.
4.2.2 Crankcase Emission Control System Group
These devices have acceptable driveability and safety characteristics, if installed
and maintained satisfactorily. Since the devices evaluated are basically the same
as the ones already in use on vehicles, driveability and safety tests were not
conducted.
4.2.3 Fuel Evaporation Emission Control System Group
Although a device of this type was not found to be available for retrofit application,
such devices should not present any driveability or safety problems. However, if
not properly designed, fire or explosion hazards may occur.
4-21
-------
4.3 RELIABILITY AND MAINTAINABILITY
Reliability and maintainability analyses were conducted on those devices for which
sufficient system data were obtained or developed. These analyses were mainly
limited by the completeness of functional and design information obtained from the
developers. The evaluation indicated that reliability and maintainability of most
of the devices could be improved by careful detailed design and production engineer-
ing, since the devices in general have not been designed to meet specific reliability,
maintenance, or producibility objectives.
The results of the reliability analysis indicated that none of the retrofit devices
evaluated would have a mean-miles-before-total-failure (MMBTF) of less than
50,000 miles if normal automotive design and fabrication standards are followed
in their production design and manufacture.
4.3.1 Reliability and Maintainability Analysis Approach and Results
The approach used in the reliability and maintainability analyses was to compare
device components with similar or identical conventional automotive components,
and to estimate reliability and maintenance requirements based on the generally
accepted characteristics of the comparable automotive components. It was assumed
that the ultimate design of the device would reflect the same level of reliability
and requirements for maintenance found in the similar automotive components. Thus,
the reliability estimates and maintenance requirements determined for a given
component (e.g., solenoid-actuated exhaust gas valve, vacuum hose, thermostatic
switch) were relatively uniform for all devices incorporating similar components.
The criteria used in determining acceptable reliability and maintainability
characteristics were those established by the California Health and Safety Code
for retrofit device accreditation (refer to Table 1-2). These are as follows:
a. The reliability of a device shall provide an expected useful life of
at least 50,000 miles of operation.
b. Maintenance shall not be required more than once each 12,000 miles
and shall not cost more than $15 for labor and material each time.
4.3.1.1 Reliability and Corrective Maintenance Analysis Procedure
Corrective, or repair, maintenance requirements were analyzed along with reliability,
to establish replacement parts costs and labor costs for repair. Corrective
maintenance is defined as all maintenance and inspection action resulting from
failure of a device totally or partially as a result of component failure. This
type of maintenance is the opposite of preventive, or planned maintenance performed
to keep a device in good working order.
To estimate reliability and corrective maintenance costs, a listing was made of all
the components comprising each retrofit device, and the components were evaluated
individually for reliability and maintainability characteristics on the basis of
comparable counterparts in a conventional automotive system. For example, a sole-
noid actuator was considered similar to a starter solenoid, and a vacuum regulated
4-22
-------
actuator was considered similar to a vacuum advance unit. Using this comparative
basis for evaluation, the following values were estimated for each component of the
retrofit device:
a. Failure Interval; This was estimated in terms of the parameters, mean-
miles-before-partial-failure (MMBPF) and mean-miles-before-total-failure
(MMBTF). The MMBPF was the expected number of miles a device would be in
operating condition (available to perform its function), based on the
mean of all partial failures it might have during its service life, while
the MMBTF was the total service life of a device based on all complete
failures after which a device would have to be replaced as a unit.
b. Replacement Parts Cost; This cost was estimated on the basis of the cost
of a comparable automotive part, considering the retail cost of device
components given by the developer.
c. Labor for Corrective Maintenance; This was the labor associated with
fixing each component failure and was based on the average California
repair rate of $12.50 per hour.
Each retrofit device was individually evaluated for component failures. The failure
intervals, replacement parts costs, and corrective maintenance actions estimated for
the retrofit devices with sufficient data are tabulated in Table 4-7. In this table,
the individual devices are listed according to general group classifications, and
the corrective maintenance actions associated with a component failure are reduced
to a list of 18 typical repair actions. Component material costs and labor hours
associated with the repair actions for each device are listed in the appropriate
matrix box. The MMBPF was estimated as the mean of the component replacement
intervals. In most cases, replacement interval data were not available to
distinguish total from partial failures; hence the MMBPF is the same as the MMBTF.
4.3.1.2 Reliability Analysis Results
The following observations are based on the reliability estimates shown in Table 4-7:
a. Almost any of the retrofit device components, if designed to normal
automotive functional, cost, and production standards, may be expected to
have a life of 50,000 miles or more, with reasonable preventive
maintenance practices.
b. Systems which use valves, switches, and electrical sensors or contacts
are prone to failure in proportion to the number of these components used.
Generally, exhaust and induction control systems which incorporate
electromechanical functions requiring valves, switches, and sensors,
are more susceptible to reliability problems and consequently have greater
need for preventive maintenance. MMBTF's estimated for these devices
were usually 50,000 miles. Conversely, induction system modifications
having no moving parts, such as carburetor jets and intake manifold
inserts have high reliability (MMBTF equal to or greater than 75,000 miles),
but generally involve some periodic inspection to verify that ignition
and carburetion tuneup adjustments are maintained and that deposit buildup
has not occurred.
4-23
-------
Table 4-7. RELIABILITY AND CORRECTIVE MAINTENANCE ESTIMATES OF DEVICES
EVALUATED IN RETROFIT PROGRAM
o
33
U
a
a
DEVICE DESCRIPTION
REPLACEMENT PARTS COST ($) /REPAIR LABOR HOURS
os
IGNITION DEVICE/
HEATING ELEMENT/
HEAT EXCHANGER
CATALYST
SPRINGS /CABLES
POINTS/CONTACTS/
SENSOR
P-
fi
VALVE
TUBING/NOZZLES
« S
ES U
fi
ELECTRONIC ASSEMBLY
1
IGNITION COIL
,
BACK PRESSURE/FLOW
CONTROL VALVE
i
i
H
b.
U
FAILURE
INTERVAL
iJ
\ll
E 0. C-
g S
as*
l||
PARTS
COST
(5)
AVERAGE COST <
REPAIR PARTS
LABOR
HOURS
1
li
GROUP 1 EXHAUST EMISSION CONTROL SYSTEMS
Type 1.1 Exhaust Gas Control Systems
1.1.1 Catalytic Converter
62
93
96
292
Catalytic Converter
Catalytic Converter with Exhaust Gas
Reclrculation, Spark Modification,
Catalytic Converter with Distributor
Vacuum Advance Disconnect
Catalytic Converter
Insufficient Data
Insufficient Data
15.00
0.50
L5.00
1.05
5.00 >
^I.IO
12.00,
45.00
0.75
SO.OOx
1.60
3.00,
125.01
4.00
60.00^
50
50
50
50
35.00
40.00
1.67
0.75
. 1.1.2 Thermal Reactor
31
244
463
468
Thermal Reaction by Turbine Blower Air
Injection
Rich Thermal Reactor
Rich Thermal Reactor with Exhauet Gas
Reclreulation and Spark Retard
Lean Thermal Reactor with Exhaust Gas
Reeireulatlon
Insuf
Insuf
iclen
Iclen
: Data
Data
20.00,
50.00.
•"1.60
80.00
''Ton
&75.0C
50
75
50
75
SO.Offl 3.00
275.0(
8.00
1.1.3 Exhauat Gas Afterburner
308
425
Exhaust Gaa Afterburner
Exhaust Gas Afterburner
2.50,
^0.25
10.00,
-"oTso
2
25.00
-'oTso
50.00
•'o.so
45.00.
6.25
^25
55.00,
"U25
140.00
^1.50
50
50
50
50
18.00
61.25
0.50
0.75
1.1.4 Exhauat Gas Filter
164
Exhauat Gas Filter
I 1
Insufficient Data
1.1.5 Exhaust Gas Backpressure
322
P
Insufficient Data
Type 1.2 Induction Control Systems
1,2.1 Air Bleed to Intake Manifold
1
42
57
401
418
433
458 ,
462
Air Bleed to Intake Manifold
Air Bleed with Exhaust Gas Recirculation
and Vacuum Advance Disconnect
Air-Vapor to Intake Manifold
Air Bleed to Intake Manifold
Air-Vapor Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air Bleed to Intake Exhaust
Manifolds
1.50,
Insuf
Insuf
icien
icien
Data
Data
Insufficient Data
2. 00,
4.00,
"1^25
12.50,
z
3.00,
-^30
2.50
3.00
"oTso
15.00,
15.00.
^6\75
15.00,
^0.60
2.00^
1.00,
"6\25
2.00,
^.25
2.50,
•^oTso
2.00,
1h25
8.00
7.50,
^60
7.5(i,
^60
48.00
X1.25
10.00
41.00
40.00
33.00.
40.00,
75
75
50
50
50
50
75
75
50
50
50
.50
14.50
10.00
10.00
13.50
13.25
13.50
0.75
1.00
1.00
0.60
0.60
0.60
A-24
-------
Table 4-7. RELIABILITY AND CORRECTIVE MAINTENANCE ESTIMATES OF DEVICES
EVALUATED IN RETROFIT PROGRAM (CONT)
u
a
DEVICE DESCRIPTION
REPLACEMENT PARTS COST {$) /REPAIR LABOR HOURS
CARBURETOR COMPONENT
IGNITION DEVICE/
HEATING ELEMENT/
HEAT EXCHANGER
CATALYST
SPRINGS/CABLES
ll
On V)
fc
,
1
TUBING/NOZZLES
HOUSING/CHAMBER/
CONTAINER
1
6-
3
|
i
1
IGNITION COIL
,
BACK PRESSURE/
FLOW CONTROL VALVE
1
£
RETROFIT DEVICE
FAILURE
INTERVAL
PARTIAL FAILURE
CMMBPF) (1,000 MILES)
MEAN MILES BEFORE
TOTAL FAILURE
(MMETF) (1,000 MILES)
PARTS
COST
AVERAGE COST OF ~
REPAIR PARTS (CRp). ~
LABOR
HOURS
i
1.2.2 Exhaust Gas Recirculation
10
245
246
Throttle-Controlled Exhaust Gas Recir-
culation with Vacuum Advance Disconnect
Variable Camshaft Timing
Speed-Controlled Exhaust Gas Reeircu-
3.50,
"0.60
,50,
"0.60
10.00,
'(h50
2.50,
2.00,
'0.30
15.00
'6/75
8.0J,
15.00.
'6\75
1.50,
'0.15
3.00,
2.00,
"6^25
6.00.
"oTso
55.00,
50.00,
'^25
61.00,
'2^25
50
75
75
50
75
75
11.00
50.00
16.00
0.55
2.25
0.87
1.2.3 Intake Manifold Modification
172
384
430
440
Intake Manifold Modification
Air-Fuel Mixture Diffuser
Induction Modification
Air-Fuel Mixture Deflection Plate
Insuf
iclen
Data
60.00
10.00
3.00
75
75
75
75
75
75
75
75
60.00
10.00
3.00
1.50
0.75
0.75
1.2.4 Carburetor Modification
33
56
268
294
295
317
Carburetor Modification, Main Jet
Differential Pressure
Crankcase Blowby and Idle Air Bleed
Modification
Modification
Exhaust Gas Recirculation with
Carburetor Modification
Carburetor Modification with Vacuum
Advance Disconnect
5.50,
0.75
Insuf
9.00,
'0\70
Icien
Data
21
A. 00,
'6^15
8.65
35.00
''T.25
70.00
'oT75
13.95
75
75
75
75
75
75
75
75
75
75
8.65
12.50
25.00
70.00
13.95
1.00
0.72
1.25
0.75
0.75
1.2.5 Turbocharger
100
1 1
Turbocharger Insufficient Data
1.2.6 Fuel Injection
175
Type 1.3 Ignition Control Systems
.3. g g
connect and Carburetor Lean Idle
Modification
Ignition Timing Modification with Lean
Idle Adjustment
1
Insufficient Data
15.00
'l.OO
25.00,
'6^35
2.00,
0.25
50.00
'UOO
32.00
'l.OO
75
75
75
75
23.00
32.00
0.65
1.00
1.3.2 Ignition Spark Modification
23
95
259
268
296
Electronic Ignition Unit
Ignition Spark Modification
P g 8
Ignition Timing and Spark Modification
Insuf
Eicien
Data
Insufficient Data
50.00
"O.T5
60.00
20.00
75
150
75
75
150
75
50.00
60.00
20.00
0.75
0.75
0.25
4-25
-------
Table 4-7. RELIABILITY AND CORRECTIVE MAINTENANCE ESTIMATES OF DEVICES
EVALUATED IN RETROFIT PROGRAM (CONCL)
DEVICE NO.
DEVICE DESCRIPTION
REPLACEMENT PARTS COST ($)/REPAIR LABOR HOURS
CARBURETOR COMPONENT
IGNITION DEVICE/
HEATING ELEMENT/
HEAT EXCHANGER
CATALYST
Oi
II
ou
cu tn
SPARK PLUGS
SWITCH
I
TUBING/NOZZLES
HOUSING/CHAMBER/
CONTAINER
a.
ELECTRONIC ASSEMBLY
u
1
IGNITION COIL
ADAPTER
BACK PRESSURE/
FLOW CONTROL VALVE
!
RETROFIT DEVICE
FAILURE
INTERVAL
,ES BEFORE
FAILURE
(1,000 MILES)
MEAN MI
PARTIAL
(MMBPF)
1
1J
» OS C
ill
PARTS
COST
11
AVERAGE
REPAIR
LABOR
HOURS
ct
M
<
C£
H *--
E ~
1.4.1 Alternative Gas Conversion
52
459
460
461
464
466
LPG Conversion
It
Compressed Natural Gas Dual-Fuel
Conversion
LPG Conversion with Exhaust R
Recirculation
Converter
eactor
st Gas
LPG-Gasoline Dual-Fuel Conversion
Insuff
Insuf
iclent Data
icien
Insufficien
Data
Data
(2)
(2)
457.95
112.00
300
451.14
^-^\ 100
I 12.00
575.00
1^\ "
"Is. oo
457^5
300
300
300
75
300
.57.9!
157.9!
(2)
575. OC
(2,
12
12
(2)
18
(2)
1.4.2 Fuel Additive
182
282
457
465
Fuel and Oil Additive
LP Gas Injection
Water Injection
Fuel Additive
I
Not A
ppllca
Insufficient
Die
Data
Not Applicable
5.00.
IhSO
20.00,
-lj.75
5.50,
1^50
12.00
1.25
80.00,
'^OO
50
50
24.50
1.20
1.4.3 Fuel Conditioner
36
279
Fuel Conditioning by Exposure
Electromagnetic Field
to
Fuel Conditioner
Type 2.1 Closed Systems
24
170
315
1
Insufficien
Data
10.00
'oTso
50
50
10.00
0.50
GROUP 2 CRANKCASE EMISSION CONTROL SYSTEMS
Heavy Duty Positive Crankcase Control
Valve with Air Bleed
Closed Blowby Control System
3.00
0.50
2.0oJ
0.25
24.40
1>T75
17.00
''1/75
50.00
100
100
50
100
100
50
24.40
17.00
18.33
0.75
1.75
0.75
Type 2.2 Open Systems
160
427
Closed or Open Blowby Control
with Filter
Closed or Open Blowby Control
with Filter
System
Syste
m
2.50
0.75
3.00
'oiTs
1.00
0.25
1.00,
0.25
3.00
0.75
4.00
0.75
53.50J
^-'"1 75
1.25
52.00J
^\ 50
i.zsl
75
50
15.00
15.00
0.75
0.75
GROUP 3 EVAPORATIVE EMISSION CONTROL SYSTEMS
467
Fuel Evaporative Control System
Insufficient Data
GROUP 4 EMISSION CONTROL COMBINATIONS
59
165
408
469
Three-Stage Exhaust Gas Contr
ol Sys
Exhaust Gas Afterburner/Recirculati
with Blowby and Fuel Evaporation
with Intake Vacuum Control an
Turbulent Mixing
Rich Thermal Reactor with Exh
Recirculation and Particulate
LEGEND:
515.00 —
Replacement parts cost
d
tern
on
aust Gas
Control
15.00,
Insuf
9.00
0.75
Insuf
Icien
10.00
icien
t Data
Data
2.00
-0,21
15.00
:2^Z5.
12.00
"liT^
5.00
0.40
3.00
5.00
0.50
8.00
0.45
4.00
Q.70
3.00
(3)^-'
'"0.15
3.00
-2.-25_
175.00
'5.00
20.00
50
50
50
50
19.50
11.50
0.75
0.81
NOTES: (1) Mean time for one repair action
-— 0.50 Hr Labor to Replace (2) Cost and labor to replace Bowden cable depends on specific installation
details. C and MTTR depend on these estimates.
(3) Three control valves
4-26
-------
c. Most retrofit emission control systems (except ignition control systems),
tend to include multiple components which represent possible failure
points. However, these components can usually be repaired without
replacing the entire system.
d. Ignition control systems are usually transistorized devices. If designed
properly, their MMBTF is greater than 75,000 miles, but failure occurs
suddenly. These devices generally have to be replaced as a total unit
upon failure as a whole or in part.
e. Those induction modifications that have no moving parts may generally
be more reliable. Air-bleed and exhaust gas recirculation induction
modifications are generally more failure prone, because they contain
more moving parts.
In summary, all retrofit devices evaluated are considered to have acceptable
reliability characteristics if conventional automotive design standards are applied
to the production models and if good preventive maintenance practices are followed
during their service life.
4.3.1.3 Maintainability Analysis Procedure
The method for estimating retrofit maintainability requirements was similar to the
method used for reliability. Maintainability was analyzed in terms of the pre-
ventive maintenance required to keep a device in satisfactory operating condition
on a planned, scheduled basis.
Each retrofit device was examined for probable preventive maintenance requirements
by considering it comparable to a conventional automotive counterpart. Using this
approach, it was reasonable to conclude that an air filter should be changed
every 12,000 miles, or a valve assembly cleaned and reset every 25,000 miles. For
each retrofit device examined the following information was determined by the
engineering evaluation team:
a. Preventive maintenance action - description.
b. Maintenance interval - quantified by the mean-miles-before-maintenance
(MMBM) interval.
c. Labor associated with the preventive maintenance action - listed as
mean-time-to-maintain (MTTM), in hours.
d. Material and parts cost for the maintenance action (C^p), in dollars.
Table 4-8 lists retrofit devices by group classification and the preventive main-
tenance actions, associated intervals, and costs. In this table, the preventive
maintenance actions were condensed to 18 typical actions encompassing the main-
tenance required for all individual devices. Maintenance intervals (MMBM),
associated labor time (MTTM), and maintenance parts cost were entered for the
preventive maintenance actions applicable to each device. If the preventive
maintenance of a device required an engine tuneup parameter adjustment, then the
time for this adjustment was included in the device maintenance time. The labor
and parts costs for complete engine tuneup are excluded from the estimates because
the retrofit contract requirements specifically excluded tuneup as a retrofit method.
4-27
-------
Table 4-8. PREVENTIVE MAINTENANCE ESTIMATES OF DEVICES
EVALUATED IN RETROFIT PROGRAM
DEVICE
NO.
DESCRIPTION
Type 1.1 Exhaust Gaa Control Systems:
62
93
96
292
Catalytic Converter
Catalytic Converter with Exhaust Gas
Recirculation, Spark Modification, and
Lean Idle Mixture
Vacuum Advance Disconnect
Y
REPLACE CATALYST
ll
OIL/FUEL/
INJECTANT
s
g
CLEAN AND REPLACE
UNIT /COMPONENT
CLEAN PARTS/
ORIFICES/VALVES
FUEL FILTERS
I
j
CHECK SWITCH OPERA-
TION (WITH METER)
VALVE ACTUATION
VOLTAGE
CHECK & ADJUST
IGNITION TIMING/
DWELL
CARBURETION
VALVE SETTING
%
1
INSPECT (VISUAL)
PLUGS & POINTS
1
i
Ck,
MEAN-MILES-BEFORE-
MAINTENANCE (MMBM)
(1,000 MILES)
COST MAINTENANCE
PARTS (Cup) $
MEAN-TIME-TO- 1
MAINTAIN (MTTM),HRS
GROUP 1 EXHAUST EMISSION CONTROL SYSTEMS;
Insi
Insi
/30
ffici
fflci
12 /
/•I*
12 :/
:nt Dal
:nt Da
a
a
8.33
12
(1)
16.25
2.50
0.27
0.25
1.1.2 Thermal Reactor
31
244
463
468
308
425
Air Injection
Rich Thermal Reactor
Rich Thermal Reactor with Exhaust Gas
Recirculatlon and Spark Retard
Lean Thermal Reactor with Exhaust Gas
Recirculation
Exhaust Gas Afterburner
Exhaust Gas Afterburner
Insu
12 /
/.25
12 /
12 /
ficie
nt Dat
12
12
12
3.00
1.25
1.25
.25
0.25
0.25
12 :/
12 /
12 /
1! './
12 /
/15
X""
12
12
3.00
1.50
0.80
0.45
1.1.4 Exhaust Gas Filter
164
Exhaust Gas Filter
Insufficl nt Data
1.1.5 Exhaust Gas Backpressure
322
Exhaust Gas Backpressure Valve
Insi
ffici
nt Data
Type 1.2 Induction Control Systems:
1.2.1 Air Bleed to Intake Manifold
1
42
57
325
401
418
433
458
462
Air Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air Bleed with Exhaust Gas Recirculation
and Vacuum Advance Disconnect
Air-Vapor Bleed to Intake Manifold
P
Air Bleed to Intake Manifold
Air-Vapor Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air Bleed to Intake and Exhaust
Manifolds
In.
Insi
Insi
12 /
12 /
/.10
X
ffici
X
fflci
fflci
%
2.5/
nt Dai
%
nt Dat
'.nt Dat
a
a
8
%
2.5 /
X
X
X
%
12 /
/TlO
12 /
12 /
/.15
X
12 /
12 /
12
12
12
2.5
2,5
2.5
2.50
0
2.50
2.30
12. 50'
2.30
0.30
0.20
0.40
0.50
0.50
0.50
4-28
-------
Table 4-8. PREVENTIVE MAINTENANCE ESTIMATES OF DEVICES
EVALUATED IN RETROFIT PROGRAM (CONT)
DEVICE
NO.
10
245
246
DESCRIPTION
Variable Camshaft Timing
Speed-Controlled Exhaust Gas Recircu-
REPLACE CATALYST
AIR, EGR, BLOWBY
FILTER
OIL/FUEL/
I NJECT ANT
CLEAN & REPLACE
UNIT/COMPONENT
CLEAN PARTS/
ORIFICES/VALVES
05
H
,-J
LINES
CHECK SWITCH OPERA-
TION (WITH METER)
Z
VOLTAGE
CHECK & ADJUST
IGNITION TIMING/
DWELL
CARBURETION
VALVE SETTING
SWITCH SETTING
INSPECT (VISUAL)
PLUGS t, POINTS
LINES & HOSES
PIPES & CHAMBERS
MEAN-MILES-BEFORE-
MAINTENANCE (MMBM)
(1,000 MILES)
JCOST MAINTENANCE
| PARTS (Cup) $
MEAN-TIME-TO-
[MAINTAIN (MTTM),HRS
n/
X-15
6 /
/.W
12 /
/ .05
6 /
/10
12 /
/ .15
b /
/.10
%0
12 X
6 /
^
12
25
6
1.25
0
1.25
0.50
0.50
0.50
1 2 3 Intake Manifold Modification
172
384
430
440
33
288
294
317
Intake Manifold Modification
Air-Fuel Mixture Deflection Plate
1.2.4 Carburetor Modification
Differential Pressure
Carburetor Main Discharge Nozzle
Modification
Exhaust Gas Recirculation with
Carburetor Modification
u r a e en r
Carburetor Modification with Vacuum
Not
Requi
red
X
/.OS
25/
/.08
25
25
25
0
0
0
0
0
0.08
0.08
0.08
Not
Not
Ins
Requl
Requ
iffic
red
red
ent Da
.
12/
XlO
Yi/
/.IS
12/
X.10
/ .05
12 /
X/25
12/
XlO
y
, .05
12
12
12
0
2.00
0
0
0
0
0.30
0
0.50
0.20
1.2.5 Turbocharger
100
Turbocharger
Ins
jffici
ent Da
a
1.2.6 Fuel Injection
c vie nject on
Ins
.ffici
ent Da
a
X
Type 1.3 Ignition Control Systems:
69
175
Disconnect and Carburetor Lean Idle
Modification
Idle Adjustment
y
/.05
12 /
/ .05
12 /
%
12 /
/.05
X
12
0
0.30
1.3.2 Ignition Spark Modification
23
259
268
296
8
g y
Ignition Timing and Spark Modification
Ins
Not
Not
iffici
Requ
Requ
snt Da
red
Lred
•
a
^
7
X-25
%'
j
25
0
0
0
0.50
0
0
4-29
-------
Table 4-8. PREVENTIVE MAINTENANCE ESTIMATES OF DEVICES
EVALUATED IN RETROFIT PROGRAM (CONCL)
DEVICE
NO.
DESCRIPTION
Type 1.4
1.4.1
52
459
460
461
464
466
REPLACE CATALYST
K
firi
OIL/FUEL/
INJECT ANT
H
i
CLEAN & REPLACE
UN IT /COMPONENT
CLEAN PARTS/
ORIFICES/VALVES
.J
LINES
CHECK SWITCH OPERA-
TION (WITH METER)
VALVE ACTUATION
VOLTAGE
CHECK & ADJUST
IGNITION TIMING/
DWELL
CARBURETION
VALVE SETTING
SWITCH SETTING
INSPECT (VISUAL)
PLUGS & POINTS
1
1
PIPES & CHAMBERS
MEAN -MILES -BEFORE -
MAINTENAKCE (MMBM)
(1,000 MILES)
COST MAINTENANCE
PARTS (CHJ.) 5
MEAN-TIME-TO-
MAINTAIN (MTTM).,HRS
Fuel Modification;
LPG Conversion
LPG Conversion
Compressed Nat
with Deceleration Unit
jral Gas Dual-fuel Conv.
LPG Conversion with Exhaust Reactor
Pulse Air Injection and Exhaust Gas
Re circulation
Methanol Fuel Conversion with Catalytic
Converter
LPG-Gasoline Dual-Fuel Conversion
1.4.
182
282
465
Fuel
Ir
In
suffi
suffic
ient D
ient D
ata
ta
25 /^
/.25
25 /
/ .25
25 /
/ .25
7
/.25
25
25
300
25
25
2.00
2.00
2.00
2.00
0.25
0.25
0.25
0.25
2 Fuel Additive
and Oil Additive
LP Gas Injection
Fuel
1.4.
36
279
Fuel
Elec
j
Additive
Re
In
Re
place
suffic
place
Additi
ient D
e - E
ta
Additive
'ery T
ank Fu
12 :/
/.50
11
12 /
Xio
12 ,/
/fit)
12
0
0
0
0.70
3 Fuel Conditioner
Conditioning by Exposure to
tromagnetic Field
Fuel Conditioner
Type 2.1
24
170
315
Closed System:
Heavy Duty Positive
Valv
Closed Blowby
Closed Blowby
Type 2.2
160
427
Clos
with
Insufficient D
Not Required
ata
0
0
GROUP 2 CRANKCASE EMISSION CONTROL SYSTEMS'
Crankcase Control
Control System
Control System
y
/.15
25 /
X30
25 /
X-25
25/
/UO
7
/.w
25 /
/^25
25 /
Xio
..25
12
25
0
0
0
0.25
0.25
0.75
Open System:
ed or Open
Filter
Blowby Control System
Closed or Open Blowby Control System
with Filter
12 \/
//2S
15^>
/^25
10 /
/<25
^
12
5
3.00
(2)
3.00
0.25
0.46
GROUP 3 EVAPORATIVE EMISSION CONTROL SYSTEMS
467
Fuel Evaporation Control System
12 /
/^25
12
1.00
.25
GROUP 4 EMISSION CONTROL COMBINATIONS'
59
165
408
469
Three-Stage Exhaust
Gas Control System
Exhaust Gas Afterburner/Recirculation
Exhaust Ga's a
Turbulent Mix
Rich Thermal
Recirculation
nd fllowby Recirculation
ing
Reactor with Exhaust Gas
and Particulate Control
LEGEND:
X
PossiDie
Maintenance
Inter
Thous
Miles
val in— »~
ands of
nainte
Code
12 y
/.5
!,
I.
BUffit
12 /
X-15
suffic
ient D
ient D
ita
ata
12 /
/TlO
12 /
/•25
12 /
/Tio
X
12 /*
X-25
12 /
/.W
12/^
/ .05
12
12
2.50
2.00
0.50
0.50
NOTES: (1) $16.25 is the cost of replacement catalyst for an 8-cylinder
lance action required. engine every 25,000 miles; the average C^, for use in the
evaluation methodology is $5.42.
(2) $3.00 la the estimated cost of filter replacement every 15,000
Preventive miles; the average C-m for use in the evaluation methodology Is
/Maintenance $1.00.
Labor-Hours
4-30
-------
4.3.1.4 Maintainability Analysis Results
The following observations were made for the comparative maintenance estimates shown
in Table 4-8:
a. Most of the retrofit devices examined in this program have preventive
maintenance intervals (MMBM) equal to or greater than 12,000 miles. The
exceptions are the alcohol-water injection systems (Devices 325, 401, and
433) which require refill and metering valve adjustment or cleaning about
every 2,500 miles. Also, Device 246 requires cleaning of the EGR valve
every 6,000 miles.
b. Approximately 75 percent of the devices require 0.5 hour or less to main-
tain. The associated costs for maintenance parts are less than $3.00 for
most of these devices.
The catalyst system (Device 96) requires a new change of catalyst at
25,000-mile intervals at a cost of $20 for an 8-cylinder engine and
$15 for a 6-cylinder engine.
c. Maintenance requirements generally increase with the number of filters,
valves, electrical switches and hoses incorporated in the retrofit system.
d. Solid-state ignition modification systems reportedly require no preventive
maintenance.
In summary, most of the retrofit devices examined appear to have reasonable periodic
maintenance requirements and maintenance intervals of no less than 12,000 miles.
4.3.2 Effect of Retrofit Device Installation on Vehicle Reliability and
Maintainability
The possibility of increased maintenance and decreased reliability in a motor vehicle
as a result of a retrofit device use can be as unacceptable as the reliability and
maintenance characteristics of the device itself. Accordingly, each device was
examined for its impact on the reliability and maintenance of the vehicle on which
it might be installed. The observations presented below are of a general nature
based on past experience with emission control systems. The durability tests that
will be reported in Volume VI should provide some actual data to substantiate these
observations. The following observations were made:
a. The devices using ignition spark retard as an approach for emission con-
trol may cause engine overheating. A majority of these types of devices
have coolant temperature sensors which restore spark advance if overheat-
ing occurs. The possibility of exhaust valve damage and the adverse
effects of long-term exposure of other related engine components to in-
creased engine heat must be considered with these devices.
b. Exhaust gas recirculation devices may pose two problems: (1) recirculation
may provide a troublesome source of induction system contamination, and
(2) the carburetion system may require more frequent tuning to provide
satisfactory driveability.
c. Recirculation of crankcase gases to the carburetor base and air inlet
(closed systems) contaminates the carburetor and may contribute to in-
creased carburetor maintenance requirements.
d. Use of catalytic reactors, thermal reactors, and exhaust gas reactor mani-
folds has potential problems of increased exhaust backpressure and higher
temperature; this may result in hotter valve operation.
4-31
-------
e. Capacitive discharge ignition systems may require more.frequent replacement
of the high voltage wires and coil used in conventional ignition systems,
because of increased susceptibility of conventional system components to
deterioration.
4.3.3 Retrofit Emission Inspection Requirements
An inspection program is recommended as a necessary part of any program of vehicle
emission control incorporating retrofit devices. Each of the 65 retrofit systems
evaluated have specific inspection and maintenance requirements which control their
installation and use. Although these requirements may vary from one device to the
next, they all have in common the objective of reducing vehicle emissions.
Vehicles equipped with an exhaust control device should receive an emission test to
verify satisfactory device operation in terms of actual emission reduction. This
test is required because of the many variables that used cars and installation
personnel can introduce to make a retrofit device ineffective.
The retrofit crankcase blowby control device should be inspected for correct func-
tional operation to the device manufacturer's specifications. There is no information
on inspection requirements for retrofit fuel evaporative control systems.
4.3.3.1 Retrofit Program Inspection and Maintenance Requirements
To achieve maximum effectiveness of the retrofit device installation, each used
vehicle within the jurisdiction of a retrofit program should be inspected and
adjusted for minimum emissions at the time of retrofit device initial installation.
Also periodic inspections of the device operation and engine tuneup should be
conducted. A Northrop Corporation study concluded that vehicles experience degrada-
tion in exhaust pollutants as they accumulate mileage and age.(l) Lower levels of
emissions are achievable when vehicles are serviced and adjustments made to engine,
carburetor, and ignition systems.
Most of the retrofit devices evaluated were found to require maintenance usually at a
frequency of 12,000 miles. Depending on the driving habits of individual motorists,
this would require servicing the device periodically at an interval of once every
12-24 months. The recommended interval and maintenance procedure would be dependent
on the respective device and manufacturer. Requirements for defective or worn parts
replacement, along with the procedures, must be defined by the retrofit manufacturer
based on reliability and maintainability analyses conducted prior to State and/or
Federal certification.
4.3.3.2 Emission Inspection Criteria
Inspection criteria should be established to identify those retrofit devices and
systems that have failed or are marginal in performance, and thus require repair.
Prior to instituting an inspection program, sufficient empirical data on the certi-
fied devices and systems should be gathered to define and relate failures and
performance levels to specific corrective actions. The minimum emission and inspec-
tion criteria must include the following:
(1) Northrop Corporation Electro-Mechanical Division in association with Olson Labora-
tories, Inc., "Mandatory Vehicle Emission Inspection and Maintenance," Part B,
Test Program Final Report, Contract ARE 1522 (California Air Resources Board),
Northrop Report No. 71Y240A (two parts), 10 December 1971.
4-32
-------
a. Exhaust Control Device Emission Criteria; Exhaust emission inspection of
retrofit devices would require measuring HC, CO, and NOx levels. Emission
limits for inspection would be established for the controlled pollutants.
In selecting a retrofit device inspection procedure, careful consideration
should be given to the compatibility of the procedure for application to
new model vehicles for continued use after uncontrolled vehicles phase out.
For those retrofit devices and systems that perform as a function of engine
speed, such as in the case of some ignition timing modification and exhaust
gas recirculation types, the desired test procedure must simulate different
road speeds to provide complete evaluation of the installed retrofit system.
Conversely, if the exhaust control technique is independent of road-load
conditions, then an idle test may be sufficient. A fundamental requirement
of any inspection procedure, however, is that it provide a means of verify-
ing that the emission reduction potential of a retrofit device is being
attained within an acceptable tolerance.
b. Crankcase Blowby Device Inspection Criteria; Retrofit crankcase emission
control systems would be subjected to an operational check and a visual
component inspection. These devices may be inspected using crankcase
vacuum or pressure as a means of establishing failure levels. A crankcase
vacuum measurement at idle would provide an objective performance test
that is more effective than a physical inspection of the system. This
would include measuring the crankcase vacuum or pressure and comparing
it to a rejection level. For the "open" crankcase systems, the inspection
criteria would require a crankcase vacuum measurement which would assure
the inspector that no blowby outflow to the atmosphere is occurring.
The "closed" or "sealed" crankcase systems criteria could allow some
crankcase pressure because all crankcase openings are closed to the
atmosphere.
Past experience at Olson Laboratories has shown that a crankcase pressure
of approximately 3 inches of water is acceptable for closed systems without
any adverse effect on car operation or crankcase system performance. Most
closed systems are designed to operate from 1 to 2 inches of water crank-
case vacuum on a vehicle with average blowby flow rates.
Detailed procedures for inspecting and measuring the performance of
crankcase systems are given in California documents. (^-' (2)
c. Fuel Evaporative System Inspection Criteria; Retrofit fuel evaporative
emission control systems would have to be subjected to visual inspection
for correct operation and fuel leaks. The pressure/vacuum safety relief
system could be inspected with pressure gage instrumentation.
Quality audits of the vehicle population could be performed using the 1972
Federal Test Procedure for evaporative emissions.
^ "California Test Procedure and Criteria for Motor Vehicle Crankcase Emission
Control," California Air Resources Board, 16 August 1966.
Handbook, Pollution Control Device Installation and Inspection, HPH 82.1, Calif-
ornia Highway Patrol, April 1971.
4-33
-------
4.3.3.3 Feasibility of Retrofit Inspection and Maintenance
A network of inspection and maintenance facilities to assure that installed devices
and systems are operating as intended would maximize achievement of the emission
reduction goals and objectives of a retrofit program. Although the feasibility
analysis relative to an inspection and maintenance program for retrofit systems is
beyond the scope of this present study, the factors and tasks that should be con-
sidered in such an analysis include the following:
a. instrumentation and Equipment Required; This task would identify those
instruments, equipment, tools, and fixtures required to inspect and
service the retrofit device and systems as installed on the affected
vehicles. Initial acquisition costs, service contracts and warranties,
operating and maintenance manuals, spare parts lists, and other items
related to these hardware requirements would be defined.
Typical instruments would include HC, CO, and NOx analyzers. Equipment
would include chassis dynamometers, diagnositic consoles, and vehicle
lifts, if applicable to the selected inspection procedure. Tools and
fixtures may include vacuum and pressure gauges.
Other requirements are documented test and inspection procedures, service
and repair procedures for the devices, and any data handling procedures
and/or computerized programs.
b. Technical Personnel Qualifications and Training; The technical personnel
may be categorized into inspection types and maintenance types. Depend-
ing on the facility configuration, the inspection and maintenance techni-
cian may be one and the same. Personnel qualifications and training
requirements are dependent on inspection procedures and associated in-
strumentation relative to a specific retrofit technique.
The physical installation of the devices evaluated require normal
automotive mechanic skills. However, most auto mechanics are not pre-
sently capable of properly adjusting a retrofit device and related
engine tuneup parameters for low emissions without some additional
training. Technician upgrading with training programs would be required
for a successful and effective retrofit program.
c. Facilities Requirements; Facilities may be privately owned and operated,
and regulated through State licensing. They may also be State owned and
operated, or State owned and privately operated. Each alternative
arrangement has its merits in view of the State, private industry, and
the general motorist.
Inspections may be performed at State facilities with maintenance per-
formed by the private sector. Alternatively both inspections and main-
tenance may be performed at private facilities. The economic, social,
and political implications of each arrangement should be evaluated.
4-34
-------
4.4 INITIAL AND RECURRING COSTS
4.4.1 Initial Costs
Initial costs are those incurred initially by the vehicle owner in purchasing a retro-
fit device and having it installed as an operating part of the total vehicle. The
initial costs consist of the material costs and labor costs necessary to provide a
complete retrofit device installation. Material costs include the basic device it-
self and the accessories that are necessary for a complete installation. Labor costs
include the time required to accomplish installation, and then to test or adjust the
device for operation.
The number of hours for installation, test, and adjustment was determined by esti-
mating the time required to perform each installation step of the related procedures
(see paragraph 4.5 for installation requirements). The total time was compared to
the estimate provided by the developer to determine whether there was any significant
difference between the two. The labor cost was determined by multiplying the standard
California hourly rate of $12.50 by the number of hours. The estimated retail cost of
the material was taken from the developer's source material, unless this retail cost
was considered unrealistic. In the latter case, a cost estimate based on historical
cost data for similar items was used.
As part of device installation, most developers required that the engine be "well
tuned"; however, in the retrofit program, the effect and cost of periodic tuneup was
specifically excluded, in accordance with the contract. Tuneup related costs were
included-only if the developer's installation specified a tuneup related part or
adjustment on which device performance depended. In this case, the contract exclusion
of tuneup was not considered applicable, since that exclusion was for engine tuneup
when used by itself as a retrofit approach.
4.4.2 Recurring Costs
Recurring costs are those resulting from the upkeep and operation of a retrofit device
during its service life. These costs include retrofit repair, maintenance, and the
cost of increased or decreased fuel consumption. The recurring costs are measured in
dollars per mile driven and consist of a summation of the following factors:
a. Repair Costs per Mile Driven: These costs include material and labor
costs associated with the repair of failed retrofit components. Math-
ematically they are calculated from the mean-time-to-repair (MTTR) in
hours, mean-miles-before-partial-failure (MMBPF), average costs of
repair parts (C^p), and repair labor rate (L^) in dollars per hour.
b. Preventive Maintenance Costs; These costs include material and labor
costs associated with preventative maintenance which is performed on
a planned, scheduled basis to keep the device in satisfactory oper-
ating condition. Mathematically these costs are calculated from the
mean-miles-before-maintenance (MMBM), the mean-time-to-maintain (MTTM)
in hours, the cost of maintenance parts (C^p), and the maintenance
labor rate (Lc) in dollars per hour.
c. Fuel Consumption Cost: This cost reflects the increased or decreased
fuel consumption resulting from retrofit device operation as a part of
the vehicular system. This cost, in dollars per mile driven, is computed
4-35
-------
from the fuel consumption with the device installed (in gallons per
mile), fuel consumption without the device installed, and fuel cost in
dollars per gallon.
Calculation of total recurring costs resulting from the retrofit installation were
based on the figures determined for MMBPF, MTTR, MMBM, MTTM, CRP, and CMP from the
reliability and maintainability data listed in Tables 4-7 and 4-8. The recurring
cost data were calculated using the equations outlined in Section 3 of Volume
III.
4.4.3 Initial and Recurring Cost Results
The initial and recurring costs calculated for each device are shown in Table 4-9.
The fuel consumption costs were included in the recurring cost calculations for the
devices which were tested in the retrofit program. It was not possible to include
fuel consumption for those devices which were not tested, because most developers
did not submit fuel consumption data and those who did reported improvements in
economy which were questionable. The sensitivity analysis summarized in paragraph
3.4 showed that fuel consumption change due to a device installation was the most
sensitive factor influencing recurring costs.
4.5 INSTALLATION AND SKILL LEVEL REQUIREMENTS
The initial step in defining the installation procedure for each retrofit device
was to obtain or develop installation data. This information had been specifically
requested from the developers, and much of the information 'they provided included
installation procedures on a step-by-step basis. In many cases, no procedures
were provided but illustrations of installations were available. Step-by-step pro-
cedures were then developed by comparing the vehicle with and without the device
and determining a logical installation procedure. In cases where a device was one
of those tested in the retrofit program, the actual installation procedure was used
for comparison purposes. A list of required material was prepared based on the
installation requirements. The tools, equipment, instruments, and facilities re-
quired to perform the installation, test, and adjustment procedures were similarly
identified.
Table 4-10 presents a summary of the significant installation and adjustment require-
ments for the retrofit devices studied.
If an emission inspection is required after device installation, then the automotive
mechanic's capability would have to be upgraded to include training in the tech-
nique of emission measurements and adjustments with the appropriate instrumentation.
Paragraph 4.3.3 reviews the inspection requirements for effective retrofit instal-
lations, including instrumentation and facilities.
The implementation of a retrofit emission control strategy requires quality control
of device installations and recurring maintenance and inspections. Such quality
control would require the regulation of garages and mechanic personnel to verify
their capability to install, adjust, maintain, inspect, and repair the approved
devices.
4-36
-------
Table 4-9. INITIAL AND RECURRING COSTS OF DEVICES
EVALUATED IN RETROFIT PROGRAM
DEVICE
No.
DESCRIPTION
INITIAL COST TO
CAR OWNER
RECURRING COST TO
CAR OWNER
($/100 mir
GROUP 1 EXHAUST EMISSION CONTROL SYSTEMS
62
93
96
292
31
244
463
468
308
425
164
322
1
42
57
325
401
418
433
458
462
10
245
246
294
172
384
430
440
33
56
288
295
317
100
Type 1.1 Exhaust Gas Control Systems:
1.1.1 Catalytic Converter
Catalytic Converter
Catalytic Converter with Exhaust Gas Recirculation,
Spark Modification, and Lean Idle Mixture
Catalytic Converter with Distributor Vacuum Advance
Disconnect
Catalytic Converter
1.1.2 Thermal Reactor
Thermal Reaction by Turbine Blower Air Injection
Rich Thermal Reactor
Rich Thermal Reactor with Exhaust Gas Recirculation
and Spark Retard
Lean Thermal Reactor with Exhaust Gas Recirculation,
1.1.3 Exhaust Gas Afterburner
Exhaust Gas Afterburner
Exhaust Gas Afterburner
1.1.4 Exhaust Gas Filter
Exhaust Gas Filter
1.1.5 Exhaust Gas Backpressure
Exhaust Gas Backpressure Valve
Type 1.2 Induction Control Systems:
1.2.1 Air Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air Bleed with Exhaust Gas Recirculation and Vacuum
Advance Disconnect
Air-Vapor Bleed to Intake Manifold
Air-Vapor Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air-Vapor Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air Bleed to Intake and Exhaust Manifold
1.2.2 Exhaust Gas Recirculation
Throttle-Controlled Exhaust Gas Recirculation with
Vacuum Advance Disconnect
Variable Camshaft Timing
Speed-Controlled Exhaust Gas Recirculation with
Vacuum Advance Disconnect
Exhaust Gas Recirculation with Carburetor
Modification
1.2.3 Intake Manifold Modification
Intake Manifold Modification
Air-Fuel Mixture Diffuser
Induction Modification
Air-Fuel Mixture Deflection Plate
1.2.4 Carburetor Modification
Carburetor Modification, Main Jet Differential
Pressure
Crankcase Blowby and Idle Air Bleed Modification
Carburetor Main Discharge Nozzle Modification
Carburetor with Variable Venturi
Carburetor Modification with Vacuum Advance
Disconnect
1.2.5 Turbocharger
Turbocharger
(3)
(3)
175(5>
73
£<»
(3)
(3)
71
159
103
(3)
64
23
63
56
46
(3)
56
(3)
(3)
71
78
89
(3)
79
(3)
19
12
21
54
41
79
23
(3)
(3)
(3)
0.171<2>
0.047
0.051
0.036
(3)
(3)
0.108
0.059
0.025
(3)
0.022(2)
-0. 191^2)
. 0.062
0.342
0.350
(3)
0.342
(3)
(3)
0.062(2)
0.259"'
-0.040(2)
(3)
0.0
(3)
0.004
0.004
-0.257(2)
0.048
0.144(2)
0.430(2)
0.021
(3)
4-37
-------
Table 4-9. INITIAL AND RECURRING COSTS OF DEVICES
EVALUATED IN RETROFIT PROGRAM (CONCL)
DEVICE
NO.
DESCRIPTION
INITIAL COST TO
CAR OWNER
(?)U>
RECURRING COST TO
CAR OWNER
($/100 mi)(4)
GROUP 1 EXHAUST EMISSION CONTROL SYSTEMS (Cont)
22
69
175
23
95
259
268
296
52
459
460
461
464 .
466
182
282
457
465
36
279
1.2.6 Fuel Injection
Electronic Fuel Injection
Type 1.3 Ignition Control Systems
1.3.1 Ignition Timing Modification
Electronic-Controlled Vacuum Advance Disconnect
and Carburetor Lean Idle Modification
Ignition Timing Modification with Lean Idle
Adjustment
1.3.2 Ignition Spark Modification
Electronic Ignition Unit
Ignition Spark Modification
Photocell-Controlled Ignition System
Capacitive Discharge Ignition
Ignition Timing and Spark Modification
Type 1.4 Fuel Modification
1.4.1 Alternative Gas Conversion
LPG Conversion
LPG Conversion with Deceleration Unit
Compressed Natural Gas Dual-Fuel Conversion
LPG Conversion with Exhaust Reactor Pulse Air
Injection and Exhaust Gas Recirculation
Methanol Fuel Conversion with Catalytic Converter
LPG-Gasoline Dual-Fuel Conversion
1.4.2 Fuel Additive
Fuel and Oil Additives
LP Gas Injection
Water Injection
Fuel Additive
1.4.3 Fuel Conditioner
Fuel Conditioning by Exposure to Electromagnetic
Field
Fuel Conditioner
(3)
63
45
(3)
(3)
59
69
23
608
608
601
(3)
(3)
(3)
1
118
(3)
(3)
(3)
16
(3)
0.069(2)
0.332<2>
(3)
(3)
0.025
0.0
0.0
0.021
0.021
(3)
(3)
(3)
(3)
0.293
0.073
(3)
(3)
(3)
0.0
GROUP 2 CRANKCASE EMISSION. CONTROL SYSTEMS
24
170
315
427
160
467
59
165
408
469
Type 2.1 Closed Systems
Heavy Duty Positive Crankcase Control Valve
with Air Bleed
Closed Blowby Control System
Closed Blowby Control System
Closed or Open Blowby Control System with Filter
Type 2.2 Open Systems
Closed or Open Blowby Control System with Filter
34
39
69
68
69
GROUP 3 EVAPORATIVE EMISSION CONTROL SYSTEMS
Fuel Evaporation Control System
137
0.013
0.026
0.038
0.135
0.051
(3) '
• GROUP 4 EMISSION CONTROL COMBINATIONS
Three-Stage Exhaust Gas Control System
Exhaust Gas Af terburner/Recirculation with Blowby and
and Fuel Evaporation Recirculation
Exhaust Gas and Blowby Recirculation with Intake
Vacuum Control and Turbulent Mixing
Rich Thermal Reactor with Exhaust Gas
Recirculation and Particulate Control
(3)
238
36
400
(3)
0.073
0.067
(3)
(1) Estimated retail costs of material and labor excluding engine tuneup costs not related to
device installation.
(2) Device tested in retrofit program.
(3) Insufficient data on which to base cost estimate.
(4) Recurring costs include fuel consumption change as measured during 1972 Federal Test Procedure
for emissions. For devices not tested in retrofit program, recurring costs do not include
fuel consumption effects, as fuel data from the retrofit developers were incomplete generally.
(5) For 8-cylinder engine.
4-38
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Table A-10. INSTALLATION AND SKILL LEVEL REQUIREMENTS SUMMARY
Mumber Installation
EXHAUST GAS CONTROL SYSTEMS
31 Prill and tap holes in exhau«t manifold, install turbine blower, connect
;tir injection nozzles.
6J Install the converter in place of the standard vehicle muffler. Install
,iir pump to supply auxiliary air to the converter. Connect bypass to
system to provide converter overtemperaturo protoction.
Most Complex Adjustment or
Minimum
Skill Level
Adjust air flow to exhaust system for Automotive Mechanic
Adjust air flow volume to converter
for optimum oxidation of emissions.
Install converter in exhmist system. Install engine valve timing modl-
i.'omu-'Ct ;itr pump to converter.
Adjust carburetor for lean air-fuel
mixture. Use exhaust analyzer.
Install catalytic converters, air pump, and overheat protection device.
Remove the presently installed exhaust system from the manifold and
replace with the exhaust filtering system.
Test overtemperature alarm circuit
during vehicle acceleration and
deceleration.
Automotive Mechanic
Automotive Mechanic
Automotive Mechanic
install rtir pump.
2Q-2 Install catalyst e
308 Install ;ifterburner in exhaust line, replace ignition points with dual
ignition points, install second coil, hook up afterburner electrically.
332 Install spring-controlled flapper valve (hinge up) to the end of the
tail pipe.
optimum oxidation of emissions.
Adjust carburetor for best lean idle
setting. Use exhaust analyzer for
Adjust carburetor air-fuel idle set-
ting to manufacturer's specifications.
Measure available spark voltage to
unit with engine analyzer.
Insufficient information for adjust-
ment of device.
Automotive Mechanic
Automotive Mechanic
Automotive Mechanic
Install afterburner unit in exhaust line, install air pump, and elec- Adjust carburetor Idel air-fuel mix- Automotive Mechanic
463 Remove vehicle exhaust manifold and replace with the Thermal Reactor.
For V-8 engines, a reactor is installed on each cylinder bank. Connect
re;ictors to vehicle exhaust system. Connect EC.R diaphragm valve to the
vacuum advance line. Connect EGR valve inlet to exhaust system. ECR
668 Insufficient data.
INDUCTION CONTROL SYSTEMS
1 Install adapter plate between carburetor and intake manifold, mount
va Ive body assembly in engine compartment, and connect va Ive body to
adapter plate.
10 Install adapter plate between carburetor and intake manifold. Replace
inner venturi in carburetor with vaporizer. Connect reclrculating tube
>2 Insufficient data.
33 Drill holes in top of carburetor fuel bowl and in Intake manifold. Con
nect these holes with hose that includes a vacuum adjustment valve.
42 Drill holes in intake manifold and air filter casing. Install con-
nectors and hook up device with hose.
56 Replace idle mixture screws with special screws, install adapter plate
between carburetor and intake manifold, mount vacuum switch and heater
assembly on carburetor, connect hoses and wiring.
57 Install adapter plate between carburetor and intake manifold. Install
vacuum disconnect switch and vacuum hoses.
Automotive Mechanic
ture to 11.5:1. Use exhaust analyzer.
Adjust exhaust recycle gas to 12 per-
cent of engine intake air. Adjust air
flow to converter for optimum emission
reduction - use exhaust analyzer.
Adjust spark advance for low emissions Automotive Mechanic
and acceptable driveabllity.
Automotive Mechanic
Balance idle air-fuel mixture screws
to obtain smoothest idle at recom-
mended speed. Adjust for combustion
efficiency of 75-80 percent. Unscrew
device counterweight for 1-3" Hg vacu-
um reduction In intake manifold vacuum.
Readjust counterweight to increase com-
bustion efficiency above 85 percent.(I)
Adjust carburetor for best idle air
fuel mixture using exhaust analyzer.
Insufficient information for device
adjustment.
Adjust device valve during steady
cruise until noting a drop in engine
rpm. Close valve slightly and lock.
Adjust the device valve with a CO
exhaust analyzer.
Test vacuum switch and heater elements Automotive Mechanic
for function. Adjust carburetor Idle
air-fuel mixture for best lean opera-
tion. Adjust idle rpm with tachometer.
Automotive Mechanic
Insufficient Info.
Automotive Mechanic
Automotive Mechanic
100 Install turbocharger in new exhaust system. Turbocharger intake air is
venturi inlet. Install electric fuel pump for high boost operation.
172 Remove intake manifold from engine and insert device into manifold.
Reinstall manifold. Install leaner primary jets in carburetor.
Automatic transmissions - adjust idle
50 rpm over manufacturer's recoromenda-
idle 75 rpm over manufacturer's recom-
mendations. Adjust carburetor idle
mixture to 86 percent combustion ef-
carbon monoxide. Idle 2200 rpm adjust
efficiency or 1.2 ±0.1 percent carbon
monoxide.(1)
Insufficient information.
Automotive Mechanic
Automotive Mechanic
Adjust engine idle rpm to manufactur- Automotive Mechanic
retor for best lean idle mixture.
4-39
-------
Table 4-10. INSTALLATION AND SKILL LEVEL REQUIREMENTS SUMMARY (CONT)
Device
Number
Installation
INDUCTION CONTROL SYSTEMS (Cont)
245 Replace valve cam timing sprocket with a new variable cam sprocket.
246 Install adapter plate between carburetor and Intake manifold. Connect
rcclrculatlng tube from exhaust to vacuum-operated shutoff valve to
adapter plate. Install solenoid valve. Replace speedometer cable with
new one having switch installed.
288 Remove venturi assembly from carburetor and install device into assem-
bly. Reassemble into carburetor.
Insufficient information for installation of the device.
Most Complex Adjustment or
Test Characteristic
Adjust basic Ignition timing to manu-
facturer's specifications. Adjust
carburetor idle air-fuel mixture for
lean operation using exhaust analyzer
Adjust carburetor for beat lean Idle
setting. Use exhaust analyzer for
optimum emissions reduction.
Adjust idle rpm and adjust carburetor
for best idle air-fuel mixture with
exhaust analyzer.
Minimum
Skill Level
Automotive Mechanic
Automotive Mechanic
Automotive Mechanic
Insufficient information for adjustment Insufficient Info.
of device. • :
295 Remove carburetor and replace with new variable venturi carburetor.
317 Replace carburetor primary metering jet, insert capillary tube in
carburetor cover, connect evaporation chamber to PCV valve.
325/ Mount a fluid reservoir in the engine compartment, install adapter
433 plate between carburetor and intake manifold, replace idle adjusting
screws with special screws, and connect hose from reservoir to adapter
plate. •
384 Remove carburetor and install device in Intake manifold. Replace
carburetor.
401 Mount fluid reservoir in engine compartment, insert T-fitting in PCV
hose, connect reservoir to T-titting.
418 Insert the device In the crankcase ventilation return line between the
PCV valve and Intake manifold.
430 Remove carburetor and install device in intake manifold. Replace-
carburetor.
460 Install device between carburetor and intake manifold.
458 Install fluid reservoir on fender wall. Insert vapor metering T-valve
in crankcase ventilation return line between PCV valve and intake mani-
fold. Connect reservoir outlet tube to the T-valve. Fill reservoir
with fluid.
462 Connect exhaust scavenger to the tapped holes in the exhaust manifold.
Install the crankcase scavenger in the positive crankcase line. Remove.
the interior part of the PCV valve.
IGNITION CONTROL SYSTEMS
23 Insufficient information for Installation of the device.
Adjust throttle linkage to carburetor.
Readjust Idle rpm and idle air-fuel
mixture for best lean operation.
Readjust basic ignition with elec-
tronic engine analyzer. Set carbu-
retor air-fuel mixture to 15:1. Reset
carburetor choke 1 division (rich)
from factory specifications.
Readjust idle rpm and idle air-fuel
mixture. Observe with engine running
that device is aerating and that all
Adjust carburetor idle air-fuel mix-
ture. Use multimeter to check for
device "shorts."
Adjust idle rpm. Adjust valve for
flow of air through device intake.
Adjust carburetor idle air-fuel mix-
ture. Use exhaust analyzer.
Adjust Idle automatic transmission to
620 rpm. Standard transmissions to
700 rpm. Adjust carburetor to minimum
HC and CO level on exhaust analyzer.
Adjust automatic choke to lean value.
Adjust engine Idle rpm and carburetor
air-fuel mixture. Use exhaust
analyzer.
Adjust carburetor Idle air-fuel mix-
ture. Use exhaust analyzer.
Automotive Mechanic
Automotive Mechanic
Automotive Mechanic
Automotive Mechanic
Automotive Mechanic
Automotive Mechanic
Automotive Mechanic
Automotive Mechanic
Automotive Mechanic
Insufficient information for adjust- Automotive Mechanic
ment of the device.
Insufficient Information for adjust-
ment of the device.
Insufficient Info.
69 Install the spark retard device, solenoid valve in vacuum advance line.
and replace idle adjust screws.
Install control unit in engine compartment, hook up wiring and vacu
hose to distributor and coil.
Replace points and condenser In distributor with photocell and shadow
disc. Install amplifier coil in engine compartment. Make wiring
connections .
Install unit in engine compartment and connect wires.
FUEL MODIFICATION SYSTEMS
36 Install the device In the fuel line between the fuel pump and the car-
buretor. Connect terminals (electrical) to 12-volt dc supply.
52 Install converter and fuel filter plus vacuum fuel lock unit. Connect
heater water to converter. Connect vacuum fuel lock to Intake manifold.
Install Type C carburetor adapter and carburetor on Intake manifold.
Install 160°F thermostat In engine cooling system. Install 35-gallon
LPG tank set, wire braid hoses, fuel gage, and remote fill Line.
Adjust ignition timing control for low Automotive Mechanic
speed engine performance. Adjust car-
buretor air- fuel for minimum emission
levels at idle rpm and trim adjustment
at 1,600 rpm,
Automotive Mechanic
engine analyzer.
Adjust engine Idle rpm and Idle air-
fuel mixture (exhaust analyzer). Ad-
just unit for proper solenoid switch
operation with engine analyzer.
Adjust basic ignition timing and test Automotive Mechanic
spark voltages with electronic engine
analyzer.
Readjust dpark plug gap and adjust
basic ignition timing with electronic
engine analyzer.
Automotive Mechanic
engine analyzer.
Insufficient information.
Automotive Mechanic
Adjust idle air-fuel mixture. Test Automotive Mechanic
for leaks. Adjust power mixture at
wide open throttle.
4-40
-------
Table 4-10. INSTALLATION AND SKILL LEVEL REQUIREMENTS SUMMARY (CONCL)
Numbgr Installation
FUEL MODIFICATION SYSTEMS (Cont)
182 Fuel additive; no Installation required.
Most Complex Adjustment or
Test Characteristic
Skill Level
Check condition of fuel filter. Re- Vehicle owner
place as neceasary.
279 Mount the device in the engine compartment and connect It into the fuel Check system for electrical leaks, or Automotive Mechanic
line between fuel pump and carburetor. Connect electrical wiring. shorts,
282 Mount LPG tank in trunk of car, mount regulating valve assembly, connect Adjust setting of regulating valve to Automotive Mechanic
with copper tubing from tank to valve to intake. minimize ignition spark knock (ping-
ing). Check system for leaks.
457 Insufficient Information. Insufficient information Insufficient Info.
459 Insufficient information. Adjust fuel flow valve and air flow Automotive Mechanic
valve drag linkage.
460' Install pressure regulators on left front side of engine compartment. Adjust final pressure for light load Automotive Mechanic
Install mixer on carburetor. Install connector and fuel filter plus operation. Adjust mixer idle screw
vacuum fuel lock unit. Connect heater water to converter. Connect to lean drop-off point.
vacuum fuel lock to intake manifold. Install 160°F thermostat In en-
gine cooling system. Install CNG tanks, fuel lines, solenoid valves
and Bowden control cable.
461 Insufficient information. Insufficient information. Insufficient Info.
464 Install carburetor modification kit for conversion of gasoline fuel to Adjust carburetor for air-methanol Automotive Mechanic
methanol. Install converter close as possible to exhaust manifold. (fuel) mixture.
Install air pump and connect air supply to converter.
465 Fuel additive; no installation required. Insufficient Information available for Insufficient Info.
preparation of additive-treated fuel.
466 Install converter and fuel filter plus vacuum fuel lock unit. Connect Adjust Idle air-fuel mixture. Test Automotive Mechanic
heater water to converter. Connect vacuum fuel lock to intake manifold. for leaks. Adjust power mixture at
Install Type C carburetor adapter and carburetor on intake manifold. wide open throttle.
Install 160°F thermostat in engine cooling system. Install tank set,
hoses, fuel gage and remote fill line.
CRANKCASE EMISSION CONTROL SYSTEMS
24 Replace PCV valve with variable jet valve. Install separator unit in Check crankcase pressure (or vacuum) Automotive Mechanic
blowby line between variable jet valve and the crankcase. after installing device.
160 Mount filter unit in engine compartment, install hose adapter fittings. Readjust carburetor for best lean idle Automotive Mechanic
and connect hoses. air-f uel mixture. Set id le rpm to
manufacturer's specifications.
170 Replace PCV valve with a special valve, connect hoses, plug and seal Adjust device metering valve to obtain Automotive Mechanic
all outlets to the crankcase. 4-5" Hg vacuum at idle rpm. Readjust
carburetor to obtain best idle rpm and
Idle air-fuel mixture. Use exhaust
analyzer.
315 Replace PCV valve with an adjustable flow control valve. Connect con- Adjust control valve to maintain vacu- Automotive Mechanic
trol valve linkage to accelerator pedal Linkage. Replace oil fill cap. urn of 0.5 inch Hg at valve cover. Re-
Install adapter plate between carburetor and intake manifold. adjust carburetor for best Idle air-
fuel mixture - use exhaust analyzer.
Set idle rpm.
427 Mount the filter unit in the engine compartment, replace PCV valve with Adjust carburetor for best lean opera- Automotive Mechanic
special part, connect to filter unit. tion. Use exhaust analyzer. Set idle
rpm.
EVAPORATIVE EMISSION CONTROL SYSTEMS
467 Replace existing gas tank with a sealed gas tank; install vapor sepa- Insufficient Information Automotive Mechanic
rator, carbon canister, connecting tubing, three-way check valve, check
valve, and miscellaneous hoses, clamps, and connectors.
COMBINATIONS
59 Insufficient Information Insufficient Information Insufficient Info.
165 Install afterburner in exhaust line, connect afterburner to Intake, con- Regulate the flow of exhaust gases Automotive Mechanic
nect fuel tank emission accumulator to intake, connect crankcase emission through the afterburner and the heat
to Intake, install high voltage coil, glo plug, flow control valves, exchanger. Adjust to give best over-
filter. all engine performance.
408 Install an adapter plate between the carburetor and intake manifold.
Correct recirculatlng line from exhaust line to adapter plate. Connect
PCV valve to adapter plate. Replace oil filter cap with check valve
oil-fill cap.
Insufficient information.
Adjust acceleration valve for minimum Automotive Mechanic
exhaust gas inlet at 21" Hg vacuum at
idle. Adjust deceleration valve to
open at 25" Hg vacuum during
deceleration. ,
Insufficient informatio
Insufficient Info.
(I) "Combustion efficiency" refers to the calibration used on some engine analyzers for adjusting the air-fuel ratio.
4-41
-------
In general, the emission reduction benefit of a retrofit device on an assured
basis would require some form of emission test following installation and upon
repair action to the device. These requirements for quality control predicate a
qualified mechanic skill level, knowledgeable in retrofit device operating prin-
ciples and in the use of equipment and instrumentation capable of verifying that
a device is functioning properly. The management of a regulated quality control
system further predicates qualified inspection personnel to train and certify
mechanics for participation in a retrofit program.
The type of quality control program required to implement and sustain use of retro-
fit devices is illustrated by that used in California for the installation, adjust-
ment, servicing, inspection, and certification of vehicle pollution control equip-
ment. (1) This California program prescribes specific inspection requirements to
be followed in the certification of emission controlled vehicles upon change of •
ownership. Inspection stations are licensed by the State, and a Class A pollution
control device installer certification is required of inspection personnel. A
Class A installer has to be experienced in major automotive tuneup, with optional'
instruction from an approved school. Applicants must pass an examination before
certification is granted. Quality controls of equivalent stringency are con-
sidered essential requirements of any program based on use of retrofitted vehicle
emission control devices as a means of achieving air quality standards.
(1) Handbook for Pollution Control Device Installation and Inspection, HPH 82.1
California Highway Patrol, April 1971.
4-42
-------
5 - PERFORMANCE
ANALYSIS
-------
SECTION 5
PERFORMANCE ANALYSIS
By means of the methodology described in Section 3, an analytical evaluation was made
of those devices for which sufficient data were developed through engineering analy-
sis and test. The objective was to determine the relative index ratings of the de-
vices in terms of their effectiveness in reducing vehicle emissions, effect on
vehicle performance, and costs to the vehicle owner.
Data for the evaluation were obtained through the data survey or by test. These were
reviewed for acceptance in the engineering analysis of the retrofit devices. The
completeness of data provided by the retrofit data survey varied widely. The emission
test data provided by the developers were nearly always supported by a test report
from a recognized independent test facility. Reliability, maintainability, and cost
data were evaluated for reasonableness, and supplemented or complemented by analysis
when sufficient system information was available. Driveability data were for the
most part incomplete, because of the lack of data on baseline vehicle driveability.
Fuel consumption data were generally not provided. Therefore, driveability and fuel
consumption evaluation was made only on those devices tested in the retrofit program.
Eleven devices were tested for emission reduction, fuel consumption, and driveability.
Four of these devices were selected for more extensive emission, fuel consumption,
and driveability testing to obtain data samples from a variety of used cars in two
different geographic areas of the U.S., as described in Section 4. Table 5-1 summa-
rizes all of the available performance data of the devices that were tested and the
devices that received an engineering evaluation based on data supplied by the
developer.
5.1 CRITERIA INDEX
cThe Criteria Index measures the ability of a device to meet legal constraints and
specified limits that could be imposed for critical performance parameters. Values
for the various Criteria Index factors were assigned 1 or 0 depending on whether or
not the evaluation criteria presented in Table 1-2 were satisfied. In all cases,
inadequate data supplied by the developers prevented complete Criteria Index evalu-
ations of the devices. As a result, the Criteria Index could be established only
for some devices. Certain devices were found to have a value of 0 for at least one
of the criteria index factors. In these cases the Criteria Index was also 0, since
this index is the product of the individual factors.
In the retrofit test program, CVS tests were conducted under the 1972 Federal Test
Procedure, for which no used car emission standards had been established at the
time of this study. Therefore, the emission standard criteria of the Criteria Index
could not be applied to the 1972 CVS test data, and the Criteria Index could not be
established for these cases.
5-1
-------
Table 5-1. PERFORMANCE SUMMARY OF DEVICES EVALUATED IN RETROFIT PROGRAM
NOTE; THE RELIABILITY OF THE DATA SHOWN DEPENDS ON THE TYPE OF TEST PROCEDURE AND THE NUMBER OF TESTS.
DEVICE
NO.
,6<«
175
246
10
33
42
69
245
288
295
23
24
52
93
95
100
292
294
MS •
460
462
463
464
465
466
468
469
31
36
56
57
59
f>2
160
182
244
315
317
DESCRIPTION
Devices with up to 18 Tests In Retrofit
Air Bleed to Intake Manifold
Catalytic Converter with Distributor
Vacuum Advance Disconnect
Iginition Timing Modification with Lean
Idle Adjustment
Speed-Controlled Exhaust Gas Recircula-
tion with Vacuum Advance Disconnect
Throttle-Controlled Exhaust Gas Reciru-
lation with Vacuum Advance Disconnect
Carburetor Modification, Main Jet
Air Bleed to Intake Manifold
Electronic-Controlled Vacuum Advanre
Modification
Variable Camshaft Timing
Carburetor Main Discharge Nozzle
Modification
Carburetor with Variable Venturi
Devices Evaluated Based on Developer and
Electronic Ignition Unit
Heavy Duty Positive Crankcase Control
Valve with Air Bleed
LPG Conversion
Catalytic Converter with Exhaust1 Gas
Lean Idle Mixture
Ignition Spark Modification
Turbocharger '
Catalytic Converter
Exhaust Gas Recirculation with
Air Bleed to Intake Manifold
Unit
Compressed Natural Gas Dual-Fuel
Conversion
Pulse Air Injection and Exhaust Gas
Air Bleed to Intake and Exhaust
Manifold
Rich Thermal Reactor with Exhaust Gas
Recirculation and Spark Retard
Methanol Fuel Conversion with Catalytic
Converter
Fuel Additive
LPG-Gasoline Dual-Fuel Conversion
Lean Thermal Reactor with Exhaust Gas
Recirculation
Rich Thermal Reactor with Exhaust Gas
Thermal Reaction by Turbine Blower Air
Injection
Fuel Conditioning by Exposure to
Electromagnetic Field
Crankcase Blowby and Idle Air Bleed
Modification
Air Bleed with Exhaust Gas Recirculation
and Vacuum Advance Disconnect
Three-Stage Exhaust Gas Control System
Catalytic Converter
Closed or Open Blowby Control System
with Filter
Fuel and Oil Additives
Rich Thermal Reactor
Closed Blowby Control System
Carb Mod with Vac Adv Disconnect
CRITERIA
INDEX
Program (1
(1)
0
0
0
ogram (197
(1)
0
(1)
(1)
0
0
0
EPA Data:
0
(1)
0
(1)
0
(1)
0
0
(1)
0
0
(1)
CD
(1)
(1)
(1)
(1)
0
0
0
0
0
0
(1)
0
0
0
0
NUMBER
OF
TESTS
)72 Fede
ie
17
10
15
2
2
2
3
]
2
1
1
(8)
18
fi
1
I
1
1
(9)
1
(21)
3
6
1
6
5
2
6
(ID
3
1
1
1
1
(12)
(10)
1(13)
3
AVERAGE
EMISSION
INDEX
PER UNIT<2>
REDUCTION
ral Test Proc
0.247
0.596
- 0.343
0.302
0.396
0.118
0.237
0.287
-0.139
0.074
0.028
-0.231
0.079
0.771
(10)
-0.251
0.113
0.156
-0.128
0.165
-0.277
0.024
(10)
(10)
0.101
0.393
(10)
0.630
(10)
-0.065(13)
(10)
0.516
0.204
0.218
(10)
0.269
0.750(13)
0.281
0.297
AVERAGE
DRIVE ABILITY
INDEX
RATING
POINTS
sdure) :
0.138
0.304
0.118
0.113
0.441
0.181
0.116
0.087
0.895 '
-0.459
3.261(20
(10) (6)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
COST INDEX
S/100 MILESO)
0.063
0.521
0.391
0.079
0.204
-0.229
-0.161
0.152
0.364
0.198
0.536
(10)
0.047
0.224
(10)
(10)
(10)
0.192
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
0.337
(10)
0.120
0.188
(10)
(10)
0.143
(10)
0.536
0.175
0.052
PERFORM-
ANCE
ITOEX(4)
0.103
0.163
0.067
0.134
0.105
0.174
. 0.165
0.110
-0.312
0.054
-0.603
(10) (7)
(10)
(10) .
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
COST
EFFECTIVENESS
INDEX,
UNIT REDUCTION
S/100 MILES
3.92
1.14
0.88
3.82
1.94
-0.51 (18)
-1.47 (18)
1.89
-0.38 (19)
0.37
0.05
(10)
1.68
3.44
(10)
(10)
(10)
0.81
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10!
(10)
(10)
(10)
(10)
(10)
2.74
(10)
(10)
(10)
0.19
(10)
1.39
(10)
5.71
INITIAL
COST FOR
INSTAL-
LATION
$
64
175
45
89
71
21
23
61
78
41
79
(10)
34
608
(10)
(10)
(10)
73
(10)
(10)
601
(10)
(10)
(10)
(10)
(10)
(10)
400
(10)
143
(10)
54
63
(10)
(10)
69
103
1
375
69
23
TEST
TYPE
972 FEDERAL TJ
3
RDCEDURE (CVS)
X
CoS
l/l
o
s
K
§
S
8
B
n
(16)
DATA
SOURCE
R
R
R
R
R
R
R
R
R
R
R
E
E
E
E
E
E
E
E
E
E
E
E
E
E
E
D
E
E
D
E
D
D
D
E
D
D
D
D
D
D
5-2
-------
Table 5-1. PERFORMANCE SUMMARY OF DEVICES EVALUATED IN RETROFIT PROGRAM (CONCL)
NOTE: THE RELIABILITY OF THE DATA SHOWN DEPENDS ON THE TYPE OF TEST PROCEDURE AND THE NUMBER OF TESTS.
DEVICE
NO.
322
384
401
425
430
438
165
170
279
296
325
427
433
308
457
268
282
408
440
467
DESCRIPTION
Exhaust Gas Backpressure Valve
Air-Fuel Mixture Dlffuser
Induction Modification
Air Bleed to Intake Manifold
with Blowby and Fuel Evaporation
Reclrculation
Closed Blowby Control System
Fuel Conditioner
Ignition Timing and Spark Modification
Air-Vapor Bleed to Intake Manifold
Closed or Open Blowby Control System
with Filter
Air-Vapor Bleed to Intake Manifold
Exhaust Gas Afterburner
Uater Injection
Capacltive Discharge Ignition
LP Gas Injection
Exhaust Gas and Blowby Recirculatlon with
Intake Vacuum Control and Turbulent
Mixing
Air-Fuel Mixture Deflector Plate
Fuel Evaporation Control System
CRITERIA
INDEX
0
0
0
0
0
0
0
0
0
(1)
0
(I)
0
0
(1)
(1)
(1)
0
0
(1)
' 0
NUMBER
OF
TESTS
1
1
1
1(13)
2
(15)
1
1
1
1
7
2
7
3(14)
(14)
(10)
(10)
(10)
(10)
(10)
(10)
AVERAGE
EMISSION
INDEX
PER UNIT(2)
REDUCTION
-0.258
0.297
0.094
0.970
0.267
-0.016
(10)
0.087
0.107
0.027
0.239
0.182
0.239
-0.047
0.250
(10)
(10)
(10)
(10)
(10)
(10)
(1) Criteria Index not totally determined due to lack of emission standards
(2)
(3)
t
(4) 1
(5) >
c
(6) h
I
(7)
(8) 6
t
(9) 1
(10) I
(11) 1
ndlvldual Criteria Index parameter evaluations.
egatlve sign indicates emission increase from baseline.
egatlve sign indicates cost saving due to more miles per gallon with
evlce installed.
o lead gasoline at $0.38/gallon. For the other devices, gasoline cost
alculated on basis of $0.35/gallon.
riveability Index not determinable for thl
PI not determinable due to lack of DI's for
baseline and 5 device tests for HC and CO
eats for NOx.
nknown
baseline test, and 11 device teats for HC
B or subsequent devices.
this and subsequent devices
3 baseline and 4 device
ara.
and CO only.
AVERAGE
DRIVEABILITY
INDEX
RATING
POINTS
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(io)
(10)
(10)
(10)
(12)
• (13)
(14)
(15)
(16)
(17)
(18)
(19)
(20)
(21)
COST INDEX
$/100 MILES (3)
(10)
(10)
0.442
0.377
0.030
(10)
0.549
0.065
0.033
0.031
0.454
0.271
0.454
0.250
(10)
0. 104
0.046
0.309
0.139
0.020
(10)
PERFORM-
ANCE
INDEX(4)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
COST
EFFECTIVENESS
INDEX
UNIT REDUCTION
S/100 MILES
(10)
(10)
0.21
2.57
8.90
(10)
(10)
1.34
3.24
0.87
0.53
0.67
0.53
-0.19(19)
(10)
(10)
(10)
(10)
(10)
(10)
(10)
4 tests for HC and CO; 1 teat for NOx.
HC and CO only.
1 baseline and 2 device tests on 1 car.
D - Developer Supplied Data
INITIAL
COST FOR
INSTAL-
LATION
$
(10)
(10)
46
159
19
(10)
238
39
16
23
56
68
56
71
(10)
59
69
118
36
- 12
137
TEST
TYPE
n9r
MS
1 =
8
7-CYCLE 7-MODE HOT
START
W (/>
™S~|
a
(/)
H
1
(16)
DATA
SOURCE
E
D
D
D
D
E
D
D
D
D
D
D
D
D
E
D
D
D
D
D
(10)
EPA Interim 9-Cycle, 7-Mode CVS Emission Test Procedure (refer
to Volume II, Reference 16).
gallon of fuel.
above baseline.
Validity of thla driveabillty test doubtful (see Table 4-6).
10 baseline and 9 device tests for HC and CO, and 6 baseline
and 6 device teats for NOx, on 2 cara.
Section 3 of Volume III presents a discussion of the individual Criteria Index
factors.
5.2 PERFORMANCE INDEX
The Performance Index (PI) measures the relative performance rating of the devices
and enables a further quantitative refinement beyond the Criteria Index, which is a
qualitative evaluation. The devices are listed in Table 5-1 in terms of emission
reduction, driveability, and cost indexes. The negative values shown in Table 5-1
for the Emission Index indicate an overall increase in the emission levels as a re-
sult of device installation. The highest positive numerical Emission Index value
represents the greatest ability to control (or reduce) emissions. The percentage
reductions for the individual pollutants achieved by each device are listed in
Table 4-2.
Note that all reported emission indexes were not obtained using the same testing
procedures, nor the same number of tests. This should be kept in mind when judging
the relative significance of the data.
5-3
-------
The Driveability Index, an indication of a penalty, becomes numerically smaller as
the driveability penalty becomes less. Negative values indicate an improvement in
vehicle driveability with the device installed. The devices are relatively worse
as their index values increase. The developers of devices that were not tested in
the retrofit program were generally unable to provide driveability data because of
the lack of information on their own test vehicles prior to device installation.
The Cost Index combines those parameters which determine the initial costs of a
device and the recurring costs. The initial costs are measured in terms of device
retail cost and installation cost amortized over the device lifetime. The recur-
ring costs, such as maintenance and gasoline mileage changes, are added expenses
for keeping the retrofit device in operation after installation.
Negative values for the Cost Index represent a cost savings attributable to
increased gasoline mileage. Devices are rated relatively worse as their Cost Index
values increase, since increased cost is a penalty.
The Performance Index provides the overall performance rating of devices for which
Emission, Driveability, and Cost Indexes could be calculated. The set of weighting
factors used in this analysis rate emissions twice as important as cost and cost is
rated twice as important as driveability. Other weighting factors may be used as
described in paragraph 3.4 and Table 6-13 of Volume III.
5.3 COST EFFECTIVENESS INDEX
The Cost Effectiveness Index (CEI) is intended to provide additional information to
complement the Performance Index. Should two or more devices have essentially the
same Performance Index, the one with the highest Cost Effectiveness Index would be
preferred. Cost Effectiveness is usually defined as the rate of the desired results
or the desired output versus the required cost input. In this discussion, the CEI
is defined as the ratio of the Emission Index to the Cost Index.
A thorough comparative analysis of devices by the evaluator should incorporate and
review the absolute Emission and Cost Indexes along with the Performance and Cost
Effectiveness Indexes. The reason for this is that the pure CEI ratio (by itself)
will not reveal the difference between two devices that have different absolute
Emission and Cost Indexes. The evaluator must question the merits of a device to
fit his requirements. He must ask "How much emission reduction do I need to fit
my requirements, and how much money will it cost for that reduction?" Once he has
these questions answered, he may then compare devices by reviewing the PI.
Negative values for the Cost Effectiveness Index are obtained for two reasons:
a. A cost savings was achieved due to better fuel economy. This is indicated
by a negative Cost Index.
b. An overall increase in emissions was achieved. This is indicated by a
negative Emission Index.
The first case is clearly favorable, while the second case would mean spending
money to increase emissions.
5-4
-------
For positive Cost Effectiveness Index values, the higher numbers indicate the larger
emission reductions per dollar.
5.4 FEASIBILITY
The feasibility and infeasibility of a retrofit device, within the context of this
study, can only be determined with respect to the device's applicability for use as
a retrofit method for controlling vehicle emissions. A device may be rated infeas-
ible for emission control without infringing upon its use for other applications.
For example, some devices, while being claimed as emission reduction devices, actu-
ally are devices for enhancing some engine performance parameter that only indirectly
or insignificantly reduces emissions. Any additional claims made for a device by the
developer are not considered here, because the findings of this study pertain bnly
to a device's use as a retrofit method to control vehicle emissions effectively and
without unacceptable vehicle performance and cost penalties.
To determine which devices are feasible and which are not, the evaluation criteria
presented in Table 1-2 can be applied. These criteria can be changed to fit the
specific requirements of the particular air quality control agency. In effect,
the evaluation criteria determine the feasibility or infeasibility of a device.
Those devices that passed the evaluation criteria levels would be the feasible
retrofit systems and the rest may be infeasible to some degree.
It should be mentioned that most of the devices evaluated in this study are prototype
systems. In some cases, sound engineering and manufacturing techniques may remove
the reasons for device infeasibility.
5-5
-------
6 - DEVELOPMENT STATUS
AND APPLICABILITY
-------
• SECTION 6
RETROFIT DEVICE DEVELOPMENT STATUS AND VEHICLE APPLICABILITY
Ultimately, the feasibility of a retrofit device for control of used car emissions
depends on its development status and the extent to which it is applicable to the
vehicle population which must be controlled. A device may theoretically and
experimentally indicate substantial emission reduction effectiveness at an accept-
able cost and yet require too long a period of development to be producible for
mass application. Developmental requirements may be compounded by accreditation
requirements. In a rigorously regulated accreditation program, in which specific
and perhaps severe accreditation criteria have to be met, it may take more than a
year for a device to meet the criteria and be put on the market. This would
assume, in most cases, that the device was ready for mass production at the time
the accreditation was begun. For example, although accreditation criteria for
used car exhaust control emission and fuel evaporative loss control devices were
initiated in California in 1968, only two exhaust control devices for gasoline-
fueled vehicles had been accepted under these criteria as of this report. These
were accepted in late 1971 and early 1972. Special incentives, such as State-
financed accreditation programs, could possibly accelerate and shorten the time
required for accreditation and marketing of a device.
6.1 VEHICLE APPLICABILITY OF RETROFIT DEVICES
The retrofit study program was focused on the evaluation of those devices designed
for use on "uncontrolled" vehicles. These vehicles are considered those which have
no exhaust or fuel evaporative controls, but may have crankcase blowby controls.
As shown in Table 6-1, the uncontrolled vehicle population varies nationally in
terms of model year depending on whether a car was sold new in or outside California.
Exhaust controls were required on new cars sold in California beginning in 1966 and
on new cars sold nationally in 1968. These controls are for CO and HC only. NOx
controls will not be required Federally until 1973, but were required on new cars
in California beginning in 1971.(1) Crankcase blowby controls have been in effect
since 1961 in California and since 1963 nationally; and fuel evaporative controls
were required in California and nationally in 1970 and 1971, respectively.
6.1.1 Pre-1968 Model Vehicles
Since approximately 10 percent of the nation's cars are located in California, it
is evident that the retrofit controls for exhaust systems documented in this study
(l)The 1973 national emission standard for NOx was specified in Federal Register
Volume 36, No. 128, Part II, dated 2 July 1971. The California NOx standard
for 1971 was specified in the California Health and Safety Code, Chapter 4,
Article 2, Paragraph 39101.5.
6-1
-------
Table 6-1. LIGHT-DUTY VEHICLE POPULATION AND TYPE OF EMISSION CONTROL (1)
ITEM
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
MODEL
YEAR
1970
1969
1968
1967
1966
1965
1964
1963
1962
1961
1960
1959
1958
1957
1956
1955-
AGE
YEARS
1.5
2.5
3.5
4.5
5.5
6.5
7.5
8.5
9.5
10.5
11.5
12.5
13.5
14.5
15.5
16.5+
MILEAGE (1)
13,100
22,500
31,900
41,300
50,700
60,100
69,500
78,900
88,300
97,700
107,100
116,500
125,900
135,300
144,700
154,100+
PERCENT
OF
TOTAL
9
12
11
10
9
9
7
7
6
5
4
3
3
1
1
3
VEHICLE
QUANTITY
(MILLIONS)
8.5
11.0
10.2
9.3
8.5
8.5
6.8
6.8
6.0
4.9
4.3
3.4
3.4
1.7
1.7
3.4
DEGREE OF CONTROL
EXHAUST
|
«
(1) Based on an average of 9,400 miles per year.
j^j Federal control coverage
yff\ California control coverage
1
1
Wx
wk.
W,
BLOW-
BY
1
iS
M
•
i
ii
it
m.
H
EVAPOR-
ATION
2
PERCENT
TOTAL
32
42
26
6-2
-------
would be applicable to 90 percent of the pre-1968 light duty vehicle fleet. This
would represent about 60 percent/of the light duty vehicles in the nation. Blowby
controls, however, would be applicable to only 90 percent of the pre-1963 vehicles,
or less than 25 percent of the vehicle population. A fuel evaporative loss control
system would be applicable to 90 percent of the pre-1971,vehicles. Thus, the
exhaust control systems and the fuel evaporative loss control systems are the
principal methods for retrofit to pre-1968 and pre-1971 vehicles.
6.1.2 Post-1968 Vehicles
The applicability of exhaust control retrofit devices to vehicles already equipped
with exhaust controls depends on the type of control incorporated in the vehicles
when produced. The factory installed control devices used on post-1965 vehicles
in California and on post-1967 nationally fall into two categories: engine modifi-
cation and air injection. .
The engine modification systems include many functional changes such as lean carbu-
retion, ignition timing retard at idle speed, combustion chamber redesign, and
manifold redesign. Several of the engine modification systems incorporate one or
more of the design principles on which the retrofit devices are based.
The air injection system incorporates some, of the features of.the engine modifica-
tion system. It includes an air pump that injects air into the exhaust manifold
to'more completely oxidize the hydrocarbons and carbon monoxide.
To specifically determine the applicability of each retrofit device or generic
group to these production-controlled vehicles, a detailed study and test program
would have to be performed. The functional characteristics of each original equip-
ment modification of each auto manufacturer would have to be compared to the retro-
fit device characteristics and a cost effectiveness determination made. In general,
it can be stated that not all of the retrofit devices would be feasible or practical
for additional emission reduction of vehicles already controlled. Those retrofit
devices which appear to be reasonably feasible for retrofit to controlled vehicles .
(1968 through 1971 for all of U.S. and 1966 through 1971 for California vehicles)
are discussed below.
6.1.2.1 Catalytic Reactors, Thermal Reactors, and Exhaust Gas Afterburners
In most cases, catalytic reactors, thermal reactors, and exhaust gas afterburners
could be retrofitted to 1968-1971 model cars which already have some form of exhaust
control, to provide further control of CO and HC. Installation requirements and
costs would be similar to those of the pre-1968 vehicles evaluated in the retrofit
study program. .
The main difference in cost would be whether the vehicle is already equipped with an
air injection pump, or if it has lean carburetion. The 1968-1971 model vehicles
which are already equipped with exhaust control systems generally have lean air fuel
carburetion, which might provide sufficient air. Some of the newer developments in
catalysts will reportedly convert HC, CO, and NOx when carburetor mixtures are near
stoichiometric. The catalyst systems generally, however, need external air injection
into the reactor for maximum effectiveness, as do the thermal reactors and after- '
burners. Since the latter, in addition, usually require rich air-fuel carburetion to
support the oxidation process, they would not generally be compatible with vehicles
6-3
-------
incorporating lean carburetion. Catalytic systems, therefore, would be the most like-
ly candidate in this group for retrofit to controlled vehicles. The cost versus ef-
fectiveness of this approach would have to be determined.
6.1.2.2 Exhaust Gas Recirculation
Exhaust gas recirculation (EGR) systems recirculate exhaust gases to the induction
system and dilute the air-fuel mixture delivered by the carburetor, with resultingly
lower combustion temperature and inhibition of NOx formation. These systems can be
retrofitted to cars already equipped with exhaust controls for CO and HC. The in-
stallation requirements and costs would be quite similar to those evaluated in the
retrofit program for pre-1968 cars. On cars which are factory equipped with exhaust
emission control systems with relatively lean carburetor mixtures, the addition of
an EGR system may present some driveability problems if the rate of exhaust gas re-
circulation is excessive.(1)
6.1.2.3 Distributor Vacuum Advance Disconnect
The distributor vacuum advance disconnect system provides a means of lowering HC and
NOx emissions at part throttle operation. This approach would probably be the most
cost effective to install on vehicles already equipped with HC and CO exhaust control
systems. However, this system may degrade part-throttle driveability operation and
fuel consumption. Wide open throttle performance would not be affected, because in
this mode of operation there is no manifold vacuum to operate the distributor vacuum
advance unit anyway.(1)
6.1.2.4 Air Bleed to the Intake Manifold
Air bleed systems can be retrofitted to vehicles already equipped with HC and CO ex-
haust control systems. However, it is possible that these retrofit devices could
cause serious problems by overleaning the carburetor mixture, since the 1968-71 ve-
hicles equipped with exhaust control systems already have a lean main circuit car-
buretor mixture. The air bleed system, in metering additional air, may cause exces-
sive leaning. This is particularly true in part throttle operation (10-18 inches of
mercury manifold vacuum), because the air-bleed-to-carburetor-mixture flow ratio in
the manifold may be excessive. This condition could lead to surging problems during
cruise mode operations and could also result in lean misfire. Air bleed systems may
also increase NOx slightly because of the increased availability of oxygen in the
combustion chamber.
As higher engine loads are required (less than 10 inches of mercury manifold vacuum),
the air-bleed-to-carburetor-mixture flow ratio becomes less. Therefore, the air
bleed systems should not affect driveability or engine performance at heavy engine
loads.
6.1.2.5 Gaseous Fuel Conversions
Most light duty vehicles could be converted to run on liquefied petroleum gas or
compressed natural gas, if the initial costs were not so high and if the supply of
these fuels was adequate. Gaseous fuels enable the CO, HC, and NOx reduction advan-
tages provided by high air-fuel ratios. In addition, it is generally agreed that the
(1) California recently passed a law requiring NOx control systems on 1966-70 model
vehicles, as specified in California Air Resources Board Resolution 71-110,
17 November 1971.
6-4
-------
HC emission byproducts from gaseous fueled vehicles are of lower photochemical smog
reactivity than those from gasoline fueled vehicles; however, no Federal reactivity
scale has been defined to allow quantitative correction for this factor.
The reduction in recurring vehicle maintenance costs that use of gaseous fuel sys-
tems has indicated, could offset their high initial costs, possibly within a 50,000-
mile service life. Since the natural gas and oil industry is not presently geared
to supply the quantity of fuel that would be needed to support widespread conver-
sions, the application of these conversions appears to be limited to fleet vehicles
through the 1970's.(l)
6.1.2.6 Evaporative Emission Control Systems
Fuel evaporative control systems control the hydrocarbons which would otherwise
evaporate from the fuel tank and carburetor vents of a car. Most of the evaporation
losses come from the carburetor external vents, and controls for this would be rela-
tively difficult to retrofit. Fuel tank evaporation control systems would be easier
to retrofit than carburetor vents.
Evaporative control system retrofitting may produce some serious safety hazards. An
example would be a fuel tank evaporation control system installed in the trunk of a
car. Any leaks could cause excessive fumes, which could enter the passenger com-
partment. Installation of these systems would require careful design to avoid these
hazards.
No retrofit evaporative control systems were supplied for evaluation in the retrofit
study program.
6.2 RETROFIT DEVICE DEVELOPMENT STATUS AND APPLICABILITY SUMMARY
Table 6-2 summarizes the development, manufacturing, and marketing status of devices
evaluated in the retrofit study, as well as the estimated uncontrolled vehicle
applicability. The table columns are defined as follows:
a. Development Status; This column defines the development status of the
device in that it indicates that a prototype (P) was developed and
tested on a vehicle, or that the device is in a production (PR) con-
figuration. Also of importance is whether or not the developer has
applied for a patent (DPP) - Patent Pending, or has an existing patent
(DP) on his device.
b. Estimated Applicability to Uncontrolled Used Cars; The percentage of
the uncontrolled used car population which could be retrofitted with
the device is represented by this column. Values are estimated from
retrofit developer inputs.
(1) "Emission Reduction Using Gaseous Fuels for Vehicular.-Propulsion," Final Report
on EPA Contract 70-69 by the Institute of Gas Technology, June 1971.
6-5
-------
Table 6-2. DEVELOPMENT STATUS AND APPLICABILITY OF DEVICES
EVALUATED IN RETROFIT PROGRAM
DEVICE
NO.
DESCRIPTION
DEVELOPMENT
STATUS'!)
ESTIMATED
APPLICA-
BILITY TO
UNCONTROLLED
USED CARS
00
GROUP 1 EXHAUST EMISSION CONTROL SYSTEMS
Exhaust Gas Control Systems - Type 1.1
62
93
96
292
31
244
463
468
308
425
164
322
Catalytic Converter
Catalytic Converter with Exhaust Gas Recirculation, Spark Modification, and Lean Idle Mixture
Catalytic Converter with Distributor Vacuum Advance Disconnect
Catalytic Converter
Thermal Reactor by Turbine Blower Air Injection
Rich Thermal Reactor
Rich Thermal Reactor with Exhaust Gas Recirculation and Spark Retard
Lean Thermal Reactor with Exhaust Gas Recirculation
Exhaust Gas Afterburner
Exhaust Gas Afterhurner
Exhuast Gas Filter
Exhaust Gas Backpressure Valve
p
p
P/DP
PR/DP
P
P/DP
P
P
P/DP
PR/ DP
P
P
No data
No data
90
90
No data
80
No data
No data
90
90
90
No data
Induction Control Systems - Type 1.2
1
42
57
325
401
418
433
458
462
10
245
'246
294
172
384
430
440
33
56
288
295
317
100
22
Air Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air Bleed with Exhaust Gas Recirculation and Vacuum Advance Disconnect
Air-Vapor Bleed to Intake Manifold
Air-Vapor Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air-Vapor Bleed to Intake Manifold
Air Bleed to Intake Manifold
Air Bleed to Intake and Exhaust Manifolds
Throttle-Controlled Exhaust Gas Recirculation with Vacuum Advance Disconnect
Variable Camshaft Timing
Speed-Controlled Exhaust Gas Recirculation with Vacuum Advance Disconnect
Exhaust Gas Recirculation with Carburetor Modification
Intake Manifold Modification
Air-Fuel Mixture Dlffuser
•Induction Modification
Air-Fuel Mixture Deflection Plate
Carburetor Modification, Main Jet Differential Pressure
Crankcase Blowby and Idle Air Bleed Modification
Carburetor Main Discharge Nozzle Modification
Carburetor with Variable Venturi
Carburetor Modification with Vacuum Advance Disconnect
Turbocharger
Electronic Fuel Injection
PR
PR
P
PR
PR
P
PR
P
P
PR
PR
P
P
P/DP
P
P
p/nr
p
P/DPP
P
PR
P/DPP
P
P
90
90
90
90
90
90
90
No data
No data
90
90
90
No data
90
90
90
90
90
90
90
90
90
No data
No data
Ignition Control Systems - Type 1.3
69
175
23
95
259
268
296
Electronic-Controlled Vacuum Advance Disconnect and Carburetor Lean Idle Modification
Ignition Timing Modification with Lean Idle Adjustment
Electronic Ignition Unit
Ignition Spark Modification
Photocell-Controlled Ignition System
Capacitive Discharge Ignition
Ignition Timing and Spark Modification
P
PR
P
PR/DPP
P
PR
P/DPP
90
90
No data
100
*)0
10
90
Fuel Modification - Type 1.4
52
182
465
36
279
282
457
459
460
461
464
466
LPG conversion
Fuel and Oil Additives
Fuel Additive
Fuel Conditioning by Exposure to Electromagnetic Field
Fuel Conditioner
LP Gas Injection
Water Injection
LPG Conversion with Deceleration Unit
Compressed Natural Gas Dual-Fuel Conversion
LPG Conversion with Exhaust Reactor Pulse Air Injection and Exhaust Gas Recirculation
Methanol Fuel Conversion with Catalytic Converter
LPG-Gasoline Dual-Fuel Conversion
PR/DP
PR
P
P
PR /DPP
PR/DP/DPP
No data
PR/DP
PR
No data
P
PR/DP
No data
No data
No data
No data
100
90
No data
No data
No data
No data
No data
No data
GROUP 2 CRANKCASE EMISSION CONTROL SYSTEMS
24
160
170
315
427
Heavy Duty Positive Crankcase Control Valve with Air Bleed
Closed or Open Blowby Control System with Filter
Closed Blowby Control System
Closed Blowby Control System
Closed or Open Rlowby Control System with Filter
PR
PR
PR/DP
PR /DP
PR
No data
90
90
90
90
GROUP 3 EVAPORATIVE EMISSION CONTROL SYSTEMS
467
Fuel evaporation control system
(2)
No data
GROUP 4 EMISSION CONTROL COMBINATIONS
59
165
408
469
Three-Stage Exhaust Gas Control System
Exhaust Gas Af terburner/Recirculation with Blowby and Fuel Evaporation Recirculation
Exhaust Gas and Blowby Recirculation with Intake Vacuum Control and Turbulent Mixing
Rich Thermal Reactor with Exhaust Gas Recirculation and Particulate Control
P
P
P/DP
P
90
75
90
No data
(1) P » PROTOTYPE . (2) No retrofit device of this type was found to exist except in combination with another
PR - PRODUCTION device (refer to paragraph 4.1.3).
DP - DEVICE PATENTED
DPP - DEVICE PATENT PENDING
6-6
-------
7 - GUIDELINES FOR
RETROFIT METHODS
-------
SECTION 7
GUIDELINES FOR SELECTING AND IMPLEMENTING RETROFIT METHODS
The determination that certain retrofit methods are feasible for use in controlling
used car emissions is only the starting point for applying these methods. Care-
fully planned effort is required on the part of agencies responsible for air quality
to define the requirements for retrofit methods and the standards or criteria they
must meet in their respective regions. Equally well planned and managed effort is
required to select those devices offering the optimum solution to a region's air
quality control requirements and then to manage the everyday affairs of an opera-
tional retrofit program.
The evaluation methodology developed in the retrofit study is a basic tool that can
be used by air quality control agencies to screen and select optimum retrofit
devices to meet their requirements. In addition to using this methodology, there
are a number of other steps which have to be planned for and accomplished in imple-
menting a retrofit program. The basic approach for selecting and implementing a
retrofit method of control may be summarized in the following steps:
a. Define the emission reduction that would be required from the used car
population.
b. Define the characteristics of the used vehicle population to which
retrofit methods would be applicable.
c. Identify feasible retrofit methods for application to that vehicle
population.
d. Determine which retrofit methods are most cost effective for the desired
level of emission control, giving due consideration to facilities
and labor requirements for implementing the retrofit program.
e. Define the retrofit device accreditation program.
f. Conduct the cost effectiveness studies required to verify the retrofit
program approach as being the most appropriate method of emission control.
g. Prepare an implementation plan.
h. Initiate and maintain the implementation plan.
7.1 DEFINING THE REQUIRED EMISSION REDUCTION
The State implementation plans required by the Clean Air Amendments Act of 1970
should be the means for identifying used car emission control requirements. The
air pollution caused by the used car population would have to be sufficiently
7-1
-------
detrimental to human health or welfare to justify a retrofit program. The control
of air quality is more complex than mere control of the motor vehicle population,
but those pollutants predominantly caused by vehicles can be identified and the
impact on human health and welfare assessed.
7.2 DEFINING THE RETROFIT VEHICLE POPULATION
The vehicle population to be controlled is a decisive factor in the type of retrofit
method to be implemented. The uncontrolled vehicle population has to be of suffi-
cient size and density to justify the program. Vehicle population surveys should
be conducted in air quality control regions where population densities and the
meteorological conditions of air basins are known to influence the air pollution
problems caused by vehicles. These surveys should be designed to establish the
vehicle population profile in terms of vehicle model year, engine displacement, and
ownership. Further, the survey should establish the vehicle owner attitudes and
preferences concerning retrofit controls, their costs, and the means of implementing
such controls.
7.3 IDENTIFYING CANDIDATE RETROFIT METHODS
Retrofit methods offering the type and level of control required by the air pollution
problem of the region under study should be identified. All candidate methods should
be identified on the basis of the following performance parameters:
a. Emission reduction effectiveness
b. Effect on safety, driveability, and vehicle performance including fuel
consumption changes
c. Reliability and maintainability
d. Development status
e. Initial and recurring cost
Each parameter should be given a quantitative value that represents the minimum
criteria that a device has to meet in order to be identified as a candidate for
use. These criteria will provide a means of screening devices on an initial basis
prior to indepth evaluation.
The feasibility of a retrofit control system can be determined by comparing its
performance to a set of evaluation criteria. Table 1-2 lists the evaluation
criteria used in this study and may be changed to fit the requirements of
the evaluator. A device would be considered feasible if it can meet the evalu-
ation criteria.
7.4 DETERMINING COST EFFECTIVE RETROFIT METHODS
Each device identified as a candidate should be evaluated by means of the formal
analytical evaluation methodology developed through the retrofit study. This
evaluation methodology provides a systematic means of objectively evaluating alter-
native devices in terms of their relative effectiveness and costs and performance.
The methodology can be exercised either by computer or by manual means. A sample
manual exercise of the evaluation methodology is shown in Appendix A.
7-2
-------
7.5 DEFINING THE CERTIFICATION PROGRAM
An essential element in approving a particular device or devices for use in a State
or region is the accreditation program that demonstrates that the .device actually
performs in the manner in which it was intended. If the air quality control agency
does not have significant statistical confidence in a device then an accreditation
program of adequate size should be conducted by the developer. Such elements as
sample size, reliability, durability, maintainability, and effectiveness should be
addressed in the design of the accreditation test program. The accreditation plan
must include several key elements such as:
a. General provisions for retrofit systems
b. Emission level standards
c. Accreditation procedures
d. Test procedures
e. Compliance to standards.
7.6 COST EFFECTIVENESS STUDIES OF ALTERNATIVE PROGRAMS
The cost effectiveness of a retrofit device program for the uncontrolled vehicle
population must be evaluated in order to decide whether the retrofit method of con-
trol is the most effective when all alternative methods are taken into consideration.
Alternative methods for used car control such as periodic vehicle inspection and
maintenance must be weighed against the retrofit approach to determine which is the
most cost effective for a particular region.
7.7 PREPARING AN IMPLEMENTATION PLAN
A detailed plan is required by which to control the accreditation of feasible
devices for use, to control the installation, and to control the long term mainte-
nance and continuing effectiveness of the installed devices.
An accreditation program for the certification of retrofit emission control systems
for used vehicles must be rigorously planned and managed if the retrofit systems
are to be effective in reducing vehicle air pollution.
The overall implementation plan should specify how and when the selected retrofit
method will be incorporated on the uncontrolled vehicle population, and what means
will be used to ensure long-term maintenance and effectiveness of the device.
7.8 IMPLEMENTING THE PLAN
A formally chartered agency should be assigned the responsibility for implementing
and maintaining the control plan. This responsibility includes such requirements as:
a. Training of retrofit installation, maintenance, and repair personnel.
b. Establishment of periodic inspection requirements or surveillance
techniques.
7-3
-------
c. Overall program administration within the air quality control regions
of concern.
The effective implementation and management of a sound retrofit plan is of paramount
importance, if the calculated reduction in vehicle emissions is to be realized.
This is the enforcement phase of the program, wherein the several millions of
uncontrolled vehicles are brought under control by the enforcement agency. As
indicated by the three requirements listed above, this phase implies controlling
the developers, the vehicle repair personnel, and the many vehicle owners. A task
of such a magnitude requires that the preparation described in the previous steps
be adequate and sound.
Of further consideration in the establishment and implementation of a viable
retrofit program is that the above steps not only consider the present time and
circumstances, but that all the predictable variations that could occur in the
future years be recognized and accommodated in the program. A continuing program
should be instituted which provides a periodic evaluation of the air quality problem
and the effectiveness of the program.
7-4
-------
APPENDIX A - SAMPLE
METHODOLOGY CALCULATIONS
-------
APPENDIX A
SAMPLE PERFORMANCE EVALUATION METHODOLOGY CALCULATION
A retrofit system was randomly selected to demonstrate the use of the evaluation
methodology developed in the retrofit study.
The data required to exercise the sample calculation are presented in Table A-l.
(The device is not identified for this sample calculation.) These data are from
Appendix E of Volume III. For the sample calculation, several references are made
to the equations in Section 3 of Volume III. The determination of the parameters
for the three indexes (Criteria, Performance, and Cost Effectiveness) is in the
order of natural flow. For example, the Driveability Index must be calculated to
provide an input to the Criteria Index and is later used in the calculation of the
Performance Index.
1.0 CRITERIA INDEX
The development of the Criteria Index is presented in paragraph 3.1 of Volume III.
The purpose of the Criteria Index is to identify any weak characteristics of a
particular device. For this sample calculation the assumed evaluation criteria
that a device should meet are listed in Table 1-2 (these values could vary for
different States or agencies according to their particular requirements).
1.1 EMISSION STANDARDS FACTOR
Using the assumed standards of 4.5 gm/mi for HC, 46.7 gm/mi for CO, and 3.0 gm/mi
for NOx, the evaluator compares the retrofit emission values as follows:
Assumed Retrofit Test Difference Between
Standards Emissions Stds & Retrofit
(gms/mile) (gm/mile) (gms/mile)
HC 4.50 6.17 -1.67
CO 46.70 89.83 -43.13
NOx 3.00 1.88 1.12
HC and CO levels are greater than the assumed standards. This causes the emission
standards factor to receive a rating of "0". The negative values indicate emission
levels are above standards.
A-l
-------
Table A-l. INPUT DATA FOR SAMPLE CALCULATION USING EVALUATION
METHODOLOGY
1. Emission Data (Gm/Mile):
Baseline:
Retrofit:
2. Safety Factor:
3. Driveability Test Data:
HC
A. 54
6.17
CO
70.78
89.83
NOx
2.39
1.88
This device received a safety factor of 1.
Baseline Retrofit Retrofit-Baseline
Test Parameter
Cold Stall at Idle 1 0
Stumble 2 6
Stretchiness 0 10
Start time, sec 0.5 0.5
Attempts 1 1
Hot Stretchiness 0 12
Start time, sec 0.5 0.5
Attempts 1 1
Avg Acceleration Time, sec 17.3 23.9
4. Installation and Recurring Cost Data:
Retrofit kit cost = $50.00
Installation time =2.25 hours
Labor rate = $12.50/hour
0-1 = -1
6-2 = 4
10-0 = 10
0.5(1)-0.5(1) = 0
12-0 = 12
0.5(1)-0.5(1) = 0
23.9-17.3 = 6.6
MTTR = 0 hrs (1)
MMBPF = 75,000 miles (1)
MMBTF = 75,000 miles (1)
MTTM = 0.50 hrs
MMBM = 25,000 miles
Lc = $12.50/hour
CRP = 0 (1)
CMP = 0 (2)
aD - 0.0661 gal/mile
(rB = 0.0594 gal/mile
G, = $0.35
NOTES: (1) For this device the engineering evaluation showed that the mean
miles before partial failure (MMBPF) and the mean miles before
total failure (MMBTF) are both 75,000 miles. Therefore, no labor
(MTTR) and repair parts cost (C ) are required.
RP
(2) No maintenance parts required for scheduled maintenance.
5. Reliability Data:
Mean-miles-before-total-failure (MMBTF) = 75,000 miles.
6. Maintainability:
Mean-miles-before-maintenance (MMBM) = 25,000
A-2
-------
1.2 EMISSION BASELINE FACTOR
The emission baseline factor prevents HC, CO, and NOx pollutant level increase from
baseline levels with the device installed. An experimental error is allowed due to
variations in test repeatability (10 percent used in this study) before the emission
baseline factor is set equal to zero. The per unit reductions for the three pollu-
tants are obtained using Eqs. (3.3), (3.4) and (3.5) from Section 3, Volume III and
the data from Table A-l:
HC Reduction, (R)
CO Reduction, (R)
HC
CO
LBHC "EDHC
BHC
JBCO
"EDCO
JBCO
4.54 -6.17
4.54
70.78 -89.83
70.78
-0.36 per unit
(A.I)
= -0.27 per unit (A.2)
NOx Reduction, (R)
NOx
EBNOx "EDNOx
EBNOx
2.39 -1.88
2.39
0.21 per unit (A.3)
The negative values indicate an emission increase above baseline levels. HC and CO
increased by more than 0.10 (10 percent). Therefore, the emission baseline factor
is zero.
1.3 SAFETY FACTOR
The safety factor was determined by an engineering evaluation of the device. Any
potential dangers were identifed with respect to design, installation, or modes of
operation. This device received a safety factor of 1 (Table A-l).
1.4 CRITICAL DRIVEABILITY FACTOR
In the Driveability Index (DI), the sum of the "without device" driving problems is
subtracted from the sum of the "with device" driving problems to arrive at a drive-
ability variation AD, for each parameter:
A.D = D
with device
- D
without device
There are five driveability test parameters that are considered to be critical.
These critical driveability parameters, if they exist, have an adverse effect on
the safety and, therefore, the acceptability of the device being evaluated. These
critical driveability parameters are:
Parameter
a. Stall on acceleration
b. Backfire
c. Stall at idle
d. Stall on acceleration
e. Backfire
Test AD
Cold Start driveaway test 0
Cold Start driveaway test 0
Hot Start driveaway test 0
Hot Start driveaway test 0
Hot Start driveaway test 0
A-3
-------
Since there were no critical driveability changes for this device, the critical
driveability factor is one.
1.5 GENERAL DRIVEABILITY FACTOR
The criterion for the general driveability factor requires that the Driveability
Index be no greater than 1.0. Therefore, it is necessary to calculate the Drive-
ability Index at this point. As defined in Eq. (3.7), Section 3, Volume III, the
Driveability Index equation is:
T,T nm-r ,-,™, R 5 D
'STM + "lO ADH
AD_ . -, „ ^n . -, „ ,,-„„ , , . , , -14 ^^TN . cold
D + ai2 ADs + ai3 ADsu)hot + (ai4 ADTN)
)hot + "
5 ADTNhot 16 A ai+az... +a16
Where: S. = 1/3 (Scaling factor)
The nine parameters measured during the cold driveability test and the hot drive-
ability test were:
AD = Rough Idle (Cold start and hot start test)
K..L
ADorm. = Stumble (Cold start and hot start test)
STM
AD = Hesitation (Cold start and hot start test)
H
AD = Detonation (Cold start and hot start test)
AD = Stretchiness (Cold start and hot start test)
O
AD = Surge (Cold start and hot start test)
b U
AD = Average cranking time (T) times number of engine start attempts (N)
(Cold start and hot start test)
AD = Stall at Idle (Cold test only)
b 1 i.
AD. = Acceleration from 0-60 mph, in seconds (Hot start only)
A-4
-------
Additionally, the weighting coefficients (a.) used in this study were:
Cold Driveability
CU
1-1
T3
H
JC
60
3
O
f*
ol
0.3333
-------
1.6 INSTALLATION COST FACTOR
The installation cost includes retail cost of the device, labor cost to install it,
and any special adaptive parts that may be needed. From Table A-l, the installation
cost is:
(Retrofit kit cost) plus (installation cost)
$50.00 + 2.25 hrs ($12.50/hr) = $78.13
(A. 6)
With an installation cost of less than the $85.00 criterion, the installation cost
factor is equal to one.
1.7 THE RECURRING COST FACTOR
The recurring cost of the device takes into account all of those incremental costs
due to the continued operation of the retrofit device. It includes the cost of
periodic maintenance of the device, repairs for failed parts, total replacement if
required, and any incremental losses in fuel economy. The recurring cost is given
by the equation:
Recur
Where:
MTTR
MMBPF
MTTM
MMBM
Lc
CRP
SlP
_ /MTTR MTTM\ CRP SlP ( .
\ TurMmjf TWO/TDM / -"/I •UVTDTCC' VtX/TDVt \ °T» ~ ® T>'
V MMBPF
/ C
MMBPF MMBM
(A. 7)
Mean-time-to-repair, hours
Mean-miles-before-partial-failure, miles
Mean-time-to-maintain, hours
Mean-miles-before-maintenance, miles
Labor rate, dollars per hour
Average cost of repairs, dollars per repair
Average cost of maintenance parts, dollars per maintenance action
Fuel consumed with device installed, gallons per mile
Fuel consumed without device installed (baseline), gallons per mile
Fuel cost, dollars/gallon
A-6
-------
Substituting the values from Table A-l into Eq. (A.7):
0
C
= / ° , 0.50 \/hours\ /$12.50\
\75,000 25,000/lmile / \ hour /
'Recur \ 75, 000 25,000/Vmile / \ hour / 75,000 25,000 \miles/
+ (0.0661 - 0.0594) Hr = $°-00259/mile (A-8>
The assumed recurring cost criterion is $0.00125/per mile and the limit is exceeded.
Therefore, the recurring cost factor is zero.
1.8 RELIABILITY FACTOR
From Table A-l, the MMBTF is 75,000 miles, which meets the minimum reliability
criterion. The reliability factor is one.
1.9 MAINTAINABILITY FACTOR
The MMBM given in Table A-l is 25,000 miles and is greater than the minimum maintain-
ability criterion of 12,000 miles. Therefore, the maintainability factor is one.
1.10 AVAILABILITY FACTOR
The availability factor reflects the inconvenience to the car owner and is the ratio
of the total miles of service life before device failure to the total hours for
failure repair and periodic maintenance of the device. The value for the avail-
ability factor is given by the following equation:
MMBPF
Availability, A = - . . - Miles per Repair and
(MT™) ""ntenance Hour (A.9)
Where:
MMBPF = Mean-miles-before-partial-failure
MMBM = Mean-miles-before-maintenance
MTTR = Mean- time-to-repair, hours
MTTM = Mean-time-to-maintain, hours
Substituting values:
A = - * nn_ - = 50,000 miles/repair and maintenance
(0.5) hour (A. 10)
This far exceeds the minimum criterion of 12,000 miles per repair hour so the
availability factor is equal to one.
A-7
-------
1.11 CRITERIA INDEX ANALYSIS
A summary of the Criteria Index Factor is as follows:
Criterion Does the Device Pass
Factor the Evaluation Criteria?
a. Emission standards factor 0 No
b. Emission baseline factor 0 No
c. Safety factor 1 Yes
d. Critical driveability factor 1 Yes
e. General driveability factor 1 Yes
f. Installation cost factor 1 Yes
g. Recurring cost factor 0 No
h. Reliability factor 1 Yes
i. Maintainability factor 1 Yes
j. Availability factor 1 Yes
The Criteria Index results show that the device does not meet the emission standards,
emission baseline, and recurring cost factors. This presents a warning to the
evaluator selecting a particular retrofit device to give these factors closer
attention. At this point the evaluator may exclude a particular device from further
evaluation as a retrofit emission control system.
The reader is cautioned to note that the device used for this example was randomly
selected and installed on one test vehicle. Several tests should be conducted on
each device being evaluated to establish mean values and statistical validity. The
results shown here are not conclusive.
2.0 PERFORMANCE INDEX
The Performance Index (PI) is represented by a summation equation designed to obtain
a quantitative rating of the devices under evaluation. This equation measures the
relative performance ratings of the device, and allows an objective evaluation even
if it does not pass State or regional evaluation criteria index requirements.
The general form of the Performance Index (PI) is given by the following equation:
(Emission \ /Drive- \ /
Index, Per\ _ c / ability\ . c / Cost
Unit of I M Index I Jl Index
Reduction / \Points / \$/100 miles/
Performance Index, PI = C + C + C (A.11)
A-8
-------
For this example, the weighting coefficients C]_, C2, and Cy are 4, 1, and 2, as
defined in paragraph 3.4 of Volume III.
2.1 EMISSION INDEX
The emission index (El) provides the per unit reduction of vehicle emission reduction
with the retrofit device installed from the baseline emission level of the vehicle
without the device installed. For each pollutant, this per unit reduction is
expressed by the following equation:
_T ± . , EBHC"EDHC\ . •• /EBCO"EDCOl
*" = _ : ~ I QTT^ I p 1' Pf, I p
BHC / 0 \ BCO
Where "S^" is a scale factor. It is "1" for the emission term.
Equal weighting is assumed for the emission weighting coefficients. Therefore,
Substituting the baseline and retrofit emission levels values given in Table A-l:
/4.54 - 6.17\
(70.78 - 89.83\ (2.39 - 1.88\]
y 70-78 j + a) \ 2>39 ;j
El =
= -0.139 (A.13)
2.2 DRIVEABILITY TERM
The driveability term (DI) was calculated in determining the general driveability
factor of the criteria index and the result was 0.895 See Eq. (A.5).
2.3 COST INDEX
The Cost Index (CI) combines those parameters which determine the initial costs of
a device and the recurring costs. The Initial Cost (CDj) is amortized over the
expected life (in miles) of the device.
* dollars per mile (A
Where (L- = initial cost for parts and installation and MMBTF = mean-miles-
before-total-failure.
A-9
-------
The Cost Index (CI) is:
T5iT? + CRecurr d°llarS ^ 10° miles
Where S- = Scaling factor = 100
Substituting the values given in Table A-2 and from Eqs. (A. 6) and (A. 8):
CI = IQO [ $78.13 + $0,00251 = $0.364/100 miles (A.15)
| 75,000 miles mile J
2.4 PERFORMANCE INDEX CALCULATION
Substituting equation results Eq. (A. 13) for the El, Eq. (A. 5) for the DI, and
Eq. (A.15) for the CI into Eq. (A. 11) we obtain:
PI = 44^+2 [4(-°-139) - 1(0-895) - 2(0.364)] = -0.312 (A. 16)
In general, the negative sign indicates that the cost and/or driveability penalties
are greater than any emission benefits. In this example, the emission index increase
was also a penalty.
3.0 COST EFFECTIVENESS INDEX
The Cost' Effectiveness Index (CEI) is obtained by dividing the Emission Index by
the Cost Index. Using the results of Eqs. (A. 13) and (A.15):
PFT _ EI_ _ -0.139 _ Unit Reduction , .
CEI - Cf ~ ^364 ~ -°'382 $/100 Miles (A'17)
Negative El means increased emission levels above baseline as a result of device
installation. For this example, the CEI indicates that money was spent to increase
emissions, a clearly unfavorable situation.
A-10
-------
APPENDIX B - RETROFIT
DESCRIPTION INDEX
-------
APPENDIX B
RETROFIT SYSTEM DESCRIPTION INDEX
NOTE: This appendix correlates the retrofit devices evaluated
with the respective Volume II paragraphs in which the
devices are described.
B-l
-------
RETROFIT SYSTEM DESCRIPTION INDEX
DEVICE
NO.
1
10
22
23
24
31
33
36
42
52
56
57
59
62
69
93
95
96
100
160
164
165
VOL. II
PARA.
4.1.1
4.2.1
4.6.1
5.2.1
7.1.1
3.2.4
4.4.1
6.3.1
4.1.2
6.1.1
4.4.2
4.1.3
9.1
3.1.3
5.1.1
3.1.4
5.2.2
3.1.1
4.5.1
7.2.1
3.4.1
9.2
PAGE
4-3
4-50
4-141
5-22
7-3
3-64
4-104
6-76
4-14
6-5
4-112
4-22
9-1
3-26
5-3
3-29
5-23
3-3
4-139
7-21
3-89
9-5
DEVICE
NO.
170
172
175
182
244
245
246
259
268
279
282
288
292
294
295
296
308
315
317
322
325
384
VOL. II
PARA.
7.1.2
4.3.1
5.1.2
6.2.1
3.2.1
4.2.2
4.2.3
5.2.3
5.2.4
6.3.2
6.2.3
4.4.3
3.1.2
4.2.4
4.4.4
5.2.5
3.3.1
7.1.3
4.4.5
3.5.1
4.1.4
4.3.4
PAGE
7-7
4-80
5-12
6-61
3-31
4-58
4-67
5-25
5-32
6-78
6-67
4-117
3-19
4-79
4-123
5-36
3-73
7-15
4-132
3-95
4-30
4-97
DEVICE
NO.
401
408
418
425
427
430
433
440
457
458
459
460
461
462
463
464
465
466
467
468
469
VOL. II
PARA.
4.1.5
9.3
4.1.6
3.3.2
7.2.2
4.3.2
4.1.4
4.3.3
6.2.4
4.1.7
6.1.3
6.1.6
6.1.4
4.1.8
3.2.2
6.1.5
6.2.2
6.1.2
8.1
3.2.3
9.4
PAGE
4-39
9-15
4-43
3-79
7-27
4-86
4-30
4-91
6-73
4-45
6-35
6-47
6-40
4-46
3-51
6-43
6-66
6-31
8-3
3-58
9-21
B-3
-------
APPENDIX C
VOL. II-VI CONTENTS
-------
APPENDIX C
TABLES OF CONTENTS
FOR
VOLUMES II, III, IV, V, AND VI
The tables of contents from Volumes II, III, IV, V, and
VI are presented in this appendix to provide an overview
of the subject matter of this report and to aid the
reader in locating subjects of interest.
Volume Page
II System Descriptions C-3
HI Performance Analysis C-21
IV Test and Analytical Procedures C-25
V Appendices C-21
VI Addendum for Durability Tests C-29
C-l
-------
VOLUME II
CONTENTS
Section . Page
FOREWORD „ iii
PREFACE . . . o . . v
ACKNOWLEDGMENTS . . . . . vii
GLOSSARY , viii
1 INTRODUCTION ................. 1-1
1.1 Definition of Retrofit Method and Light Duty
Vehicle '................ 1-1
1.2 Retrofit Method Classification System ....... 1-2
1.3 Data Search and Development Requirements ... ... 1-3
1.4 System Description Approach 1-4
1.5 Data Survey Results ........... 1-6
2 RETROFIT EMISSION CONTROL TECHNOLOGY ............. 2-1
2.1 Pollutants Attributable to Gasoline- and Gaseous-
Fueled Vehicles ...„ <...<, 2-1
2.2 Vehicle Sources of HC, CO and NOx ......... 2-1
2.3 Principles of Retrofit Methods for Controlling
Vehicle Emissions 2-2
2.3.1 Exhaust Emission Control Systems - Group 1 2-2
2.3.2 Crankcase Emission Control Systems - Group 2 .... 2-9
2.3.3 Evaporative Emission Control Systems - Group 3 ... 2-10
3 GROUP 1 RETROFIT METHOD DESCRIPTIONS: TYPE 1.1 - EXHAUST
GAS CONTROL SYSTEMS 3-1
3.1 Catalytic Converters - Retrofit Subtype 1.1.1 ... 3-3
3.1.1 Device 96: Catalytic Converter with Distributor
Vacuum Advance Disconnect .... . 3-3
3.1.2 Device 292: Catalytic Converter .......... 3-19
3.1.3 Device 62: Catalytic Converter ........... 3-26
3.1.4 Device 93: Catalytic Converter with Exhaust Gas
Recirculation, Spark Modification, and Lean
Idle Mixture . 3-29
3.2 Thermal Reactor - Retrofit Subtype 1.1.2 ...... 3-31
3.2.1 Device 244: Rich Thermal Reactor 3-31
3.2.2 Device 463: Rich Thermal Reactor with Exhaust Gas
Recirculation and Spark Retard .... 3-51
3.2.3 Device 468: Lean Thermal Reactor with Exhaust Gas
Recirculation .„ „ 3-58
3.2.4 Device 31: Thermal Reaction by Turbine Blower Air
Injection ..... 3-64
3.3 Exhaust Gas Afterburner - Retrofit Subtype 1.1.3 . . 3-73
3.3.1 Device 308: Exhaust Gas Afterburner „ 3-73
3.3.2 Device 425: Exhaust Gas Afterburner 3-79
C-3
-------
Section
VOLUME II
CONTENTS (CONTINUED)
3.4 Exhaust Gas Filter - Retrofit Subtype 1.1.4 .... 3-89
3.4.1 Device 164: Exhaust Gas Filter 3-89
3.5 Exhaust Gas Backpressure Control - Retrofit Sub-
type 1.1.5 3-95
3.5.1 Device 322: Exhaust Gas Backpressure Valve ..... 3-95
GROUP 1 RETROFIT METHOD DESCRIPTIONS: TYPE 1.2 - INDUCTION
CONTROL SYSTEMS . . 4-1
4.1 Air Bleed to Intake Manifold - Retrofit Subtype
1.2.1 4-3
4.1.1 Device 1: Air Bleed to Intake Manifold 4-3
4.1.2 Device 42; Air Bleed to Intake Manifold 4-14
4.1.3 Device 57: Air Bleed with Exhaust Gas Recircula-
tion and Vacuum Advance Disconnect 4-22
4.1.4 Device 325/433: Air Vapor Bleed to Intake
Manifold 4-30
4.1.5 Device 401: Air-Vapor Bleed to Intake Manifold . . . 4-39
4.1.6 Device 418: Air Bleed to Intake Manifold 4-43
4.1.7 Device 458: Air Bleed to Intake Manifold 4-45
4.1.8. Device 462: Air Bleed to Intake and Exhaust
Manifolds 4-46
4.2 Exhaust Gas Recirculation - Retrofit Subtype 1.2.2 . 4-49
4.2.1 Device 10; Throttle-Controlled Exhaust Gas Recir-
culation with Vacuum Advance Disconnect 4-50
4.2.2 Device 245: Variable Camshaft Timing 4-58
4.2.3 Device 246: Speed-Controlled Exhaust Gas Recircu-
lation with Vacuum Advance Disconnect 4-67
4.2.4 Device 294: Exhaust Gas Recirculation with
Carburetor Modification 4-79
4.3 Intake Manifold Modification - Retrofit Sub-
type 1.2.3 4-80
4.3.1 Device 172: Intake Manifold Modification 4-80
4.3.2 Device 430: Induction Modification 4-86
4.3.3 Device 440: Intake Deflection Plate 4-91
4.3.4 Device 384: Air-Fuel Mixture Diffuser 4-97
4.4 Carburetor Modification - Retrofit Subtype 1.2.4 . . 4-103
4.4.1 Device 33: Carburetor Modification, Main Jet
Differential Pressure 4-104
4.4.2 Device 56: Crankcase Blowby and Idle Air Bleed
Modification 4-112
4.4.3 Device 288: Carburetor Main Discharge Nozzle
Modification 4-117
4.4.4 Device 295: Variable Venturi Carburetor 4-123
4.4.5 Device 317: Carburetor Modification with Vacuum
Advance Disconnect 4-132
4.5 Turbocharged Engine - Retrofit Subtype 1.2.5 .... 4-139
4.5.1 Device 100; Turbocharger 4-139
4.6 Fuel Injection - Retrofit Subtype 1.2.6 4-141
4.6.1 Device 22; Electronic Fuel Injection 4-141
C-4
-------
Section
VOLUME II
CONTENTS (CONTINUED)
GROUP 1 RETROFIT METHOD DESCRIPTIONS: TYPE 1.3 -
IGNITION CONTROL SYSTEMS 5-1
5.1 Ignition Timing Modification - Retrofit Subtype
1.3.1 5-3
5.1.1 Device 69: Electronic-Controlled Vacuum Advance
Disconnect and Carburetor Lean Idle Modification . 5-3
5.1.2 Device 175: Ignition Timing Modification with
Lean Idle Adjustment 5-12
5.2 Ignition Spark Modification - Retrofit Subtype
1.3.2 5-21
5.2.1 Device 23: Electronic Ignition Unit 5-22
5.2.2 Device 95: Ignition Spark Modification 5-23
5.2.3 Device 259: Photocell-Controlled Ignition System . . 5-25
5.2.4 Device 268: Capacitive Discharge Ignition 5-32
5.2.5 Device 296: Ignition Timing and Spark Modification . 5-36
GROUP 1 RETROFIT METHOD DESCRIPTIONS: TYPE 1.4 -
FUEL MODIFICATION 6-1
6.1 Gas Conversion - Retrofit Subtype 1.4.1 6-1
6.1.1 Device 52: LPG Conversion 6-5
6.1.2 Device 466: LPG-Gasoline Dual-Fuel Conversion . . . 6-31
6.1.3 Device 459: LPG Conversion with Deceleration Unit. . 6-35
6.1.4 Device 461: LPG Conversion with Exhaust Reactor
Pulse Air Injection and Exhaust Gas Recirculation. 6-40
6.1.5 Device 464: Methanol Fuel Conversion with Catalytic
Converter 6-43
6.1.6 Device 460: Compressed Natural Gas Dual-Fuel
Conversion 6-47
6.2 Fuel Additive - Retrofit Subtype 1.4.2 6-61
6.2.1 Device 182: Fuel and Oil Additives 6-61
6.2.2 Device 465: Fuel Additive 6-66
6.2.3 Device 282: LP Gas Injector 6-67
6.2.4 Device 457: Water Injection 6-73
6.3 Fuel Conditioner - Retrofit Subtype 1.4.3 6-76
6.3.1 Device 36: Fuel Conditioning by Exposure to
Electromagnetic Field ..... . . 6-76
6.3.2 Device 279: Fuel Activator 6-78
GROUP 2 RETROFIT METHOD DESCRIPTIONS CRANKCASE EMISSION
CONTROL SYSTEMS 7-1
7.1 Closed System - Retrofit Type 2.1 7-3
7.1.1 Device 24: Heavy Duty Positive Crankcase
Control Valve with Air Bleed 7-3
7.1.2 Device 170: Closed Blowby Control System 7-7
7.1.3 Device 315: Closed Blowby Control System 7-15
. C-5
-------
Section
VOLUME II
CONTENTS (CONTINUED)
7.2 Open Systems - Retrofit Type 2.2 7-21
7.2.1 Device 160: Closed or Open Blowby Control System . . 7-21
7.2.2 Device 427: Closed or Open Blowby Control System
with Filter 7-27
GROUP 3 RETROFIT METHOD DESCRIPTIONS EVAPORATIVE EMISSION
CONTROL SYSTEMS 8-1
8.1 Device 467 Absorption-Regenerative Fuel
Evaporation Control System 8-3
8.1.1 Typical Installation Description 8-3
8.1.2 Typical Installation Initial and Recurring Cost . . 8-3
8.1.3 Feasibility Summary 8-3
GROUP 4 RETROFIT METHOD DESCRIPTIONS EMISSION CONTROL
COMBINATIONS 9-1
9.1 Device 59: Three-Stage Exhaust Gas Control System . 9-1
9.1.1 Physical Description 9-2
9.1.2 Functional Description 9-2
9.1.3 Performance Characteristics 9-2
9.1.4 Reliability 9-2
9.1.5 Maintainability 9-2
9.1.6 Driveability and Safety 9-2
9.1.7 Installation Description 9-3
9.1.8 Initial and Recurring Costs 9-3
9.1.9 Feasibility Summary 9-3
9.2 Device 165: Exhaust Gas Afterburner/Recirculation
with Blowby and Fuel Evaporation Recirculation . . 9-5
9.2.1 Physical Description 9-5
9.2.2 Functional Description 9-6
9.2.3 Performance Characteristics 9-7
9.2.4 Reliability 9-8
9.2.5 Maintainability 9-9
9.2.6 Driveability and Safety 9-9
9.2.7 Installation Description 9-9
9.2.8 Initial and Recurring Costs 9-10
9.2.9 Feasibility Summary 9-10
9.3 Device 408: Exhaust Gas and Blowby Recirculation
with Intake Vacuum Control and Turbulent Mixing . 9-15
9.3.1 Physical Description 9-15
9.3.2 Functional Description 9-15
9.3.3 Performance Characteristics 9-17
9.3.4 Reliability 9-17
9.3.5 Maintainability 9-17
9.3.6 Driveability and Safety 9-17
9.3.7 Installation Description 9-17
9.3.8 Initial and Recurring Costs 9-18
9.3.9 Feasibility Summary 9-18
C-6
-------
VOLUME II
CONTENTS (CONTINUED)
Section Page
9.4 Device 469: Thermal Reactor with Exhaust Gas Recir-
culation and Particulate Control 9-21
9.4.1 Physical Description 9-21
9.4.2 Functional Description 9-21
9.4.3 Performance Characteristics 9-23
9.4.4 Reliability 9-24
9.4.5 Maintainability 9-25
9.4.6 Driveability and Safety 9-25
9.4.7 Installation Description 9-25
9.4.8 Initial and Recurring Costs 9-26
9.4.9 Feasibility Summary 9-26
10 REFERENCES 10-1
11 RETROFIT DEVICE INDEX . . 11-1
ILLUSTRATIONS
Figure Page
2-1 Effects of Air-Fuel Ratio (Reference 114) 2-5
3-1 Device 96 Catalytic Converter Configuration Tested in
Retrofit Program - Development Model 3-4
3-2 Device 96 Catalytic Converter with Vacuum Advance Disconnect
Installation 3-5
3-3 Device 96 Catalytic Converter with Vacuum Advance Disconnect
Functional Diagram 3-7
3-4 Typical Device 292 Configuration for LPG-Fuel Material
Handling Vehicle (Reference 12) 3-19
3-5 Device 292 Configuration for Gasoline Engine (Reference 12). . 3-19
3-6 Device 292 LPG Configuration Catalytic Converter Functional
Diagram (Reference 12) 3-20
3-7 Device 292 Catalytic Converter Light Duty Vehicle Develop-
mental Configuration (Reference 12) 3-24
3-8 Device 62 Catalytic Converter Emission Reduction Performance
Versus Catalyst Temperature (Reference 8) 3-27
3-9 Device 244 Type V Thermal Reactor Physical Configuration
(Reference 72) 3-32
3-10 Device 244 Exhaust Gas Flow Through Rich Thermal Reactor
(Reference 71) 3-34
3-11 Device 244 Rich Thermal Reactor and Intake Manifold Heat
Interface (Reference 71) 3-36
3-12 Device 244 Rich Thermal Reactor Exhaust Port Insert
Alternative Configurations (Reference 71) 3-38
3-13 Device 244 Rich Thermal Reactor Emission Reduction Charac-
teristics Compared to Standard Air Injection (Reference 71). 3-39
C-7
-------
VOLUME II
ILLUSTRATIONS (CONTINUED)
Figure
3-14 Device 244 Rich Thermal Reactor Temperature Profile for
One 7-Mode Cycle (Reference 71) 3-39
3-15 Effect of Fuel Variables on Average Thickness Losses of OR-1
Alloy During Continuous Thermal Cycling (Reference 2) ... 3-41
3-16 . Device 244 Rich Thermal Reactor Core Equilibrium Tempera-
tures for Vehicle Operating Modes (Reference 71) 3-42
3-17 Condition of Device 244 Rich Thermal Reactor Components
After One Hour of Light-Off (Reference 71) 3-43
3-18 Device 244 Thermal Reactor Installation (Reference 72) .... 3-47
3-19 Device 463 Rich Thermal Reactor Model II Configuration
(Reference 101) 3-51
3-20 Effect of Flame Holders on Device 463 Rich Thermal Reactor
Warmup Time During 1968 Federal Test Procedure (Refer-
ence 101) 3-53
3-21 Device 463 Rich Thermal Reactor Installation on 1971 Ford
LTD 351-CID Engine (Reference 101) 3-56
3-22 Device 31 Turbine Blower Configuration (Developer Photo) . . . 3-64
3-23 Device 31 Air Injection System Configuration (Developer
Sketch) 3-65
3-24 Device 31 Turbine Blower Air Pumping Characteristics
(Developer Data) 3-66
3-25 Device 31 Turbine Blower Output as Percent of Engine Inlet
Airflow (Developer Data) 3-66
3-26 Device 31 Turbine Blower Emission Test Comparison with
Conventional Air Pump System (Developer Data) 3-68
3-27 Device 31 Turbine Blower Air Injection System Installation
(Developer Photo) . . 3-71
3-28 Device 308 Exhaust Gas Afterburner Showing Spark Plug (Right
Side) and Diametrically Opposed Electrode (Left Side) . . . 3-74
3-29 Device 425 Exhaust Gas Afterburner (U.S. Patent No.
3,601,982) 3-80
3-30 Device 164 Exhaust Gas Filter Components (Developer
Photograph) 3-89
3-31 Device 164 Exhaust Gas Filter Functional Schematic 3-90
4-1 Device 1 Air Bleed Components 4-4
4-2 Device 1 - Functional Schematic Diagram 4-5
4-3 Device 1 Air Bleed to Intake Manifold Typical Installation
(Developer Sketch) 4-12
4-4 Device 42: Air Bleed to Intake Manifold 4-14
4-5 Device 42 Air Bleed to Intake Manifold Functional Schematic
(Developer Diagram) . 4-15
4-6 Device 42 Air Bleed to Intake Manifold: Typical Installation
of Air Valve on Carburetor Air Cleaner (Developer Photo) . . 4-19
4-7 Device 57 Air Bleed with EGR and Vacuum Advance Disconnect
System Components .... 4-22
4-8 Device 57 Air Bleed with EGR and Vacuum Advance Disconnect
Installed on V-8 Intake Manifold (Developer Photo) 4-26
4-9 Device 325/433 Air-Vapor Bleed to Intake Manifold System
Components 4-31
C-8
-------
VOLUME II
ILLUSTRATIONS (CONTINUED)
Figure Page
4-10 Device 325/433 Air Injection Needles 4-31
4-11 Device 325/433 Air-Vapor Bleed to Intake Manifold Func-
tional Schematic (Developer Diagram) 4-32
4-12 Device 325/433 Air Needle System Compared to Standard Needle
(Developer Diagram) 4-33
4-13 Device 401 Air-Vapor Bleed to Intake Manifold System
Configuration (Developer Diagram) .... 4-39
4-14 Device 462 Air Bleed to Intake and Exhaust Manifolds Func-
tional and Installation Schematics (Reference 90) 4-47
4-15 Device 10 Throttle-Controlled EGR with Vacuum Advance
Disconnect System Configuration 4-51
4-16 Device 245 Variable Camshaft Timing Gear 4-58
4-17 Device 245 Variable Camshaft Installation 4-63
4-18 Device 246 Speed-Controlled EGR with Vacuum Advance
Disconnect System Components 4-68
4-19 Device 246 Speed-Controlled EGR with Vacuum Advance Dis-
connect Functional Schematic (Developer's Diagram) 4-68
4-20 Device 246 Speed-Controlled EGR with Vacuum Advance Dis-
connect Installation (Developer Sketch) 4-77
4-21 Device 246 Typical Installation on Retrofit Program Test
Vehicle 4-77
4-22 Device 172 Intake Manifold Modification (Developer Sketch) . . 4-81
4-23 Device 430 Intake Manifold Nozzle Screen Configuration .... 4-86
4-24 Device 430 Intake Manifold Nozzle Screen Installation .... 4-87
4-25 Device 440 Intake Deflection Plate Vehicle Manufacturer
Configurations 4-92
4-26 Device 440 Intake Deflection Plate Installed and Typical
Variations (Developer Sketch) 4-92
4-27 Device 384 Air-Fuel Mixture Diffuser (Configuration for
Two-Barrel Carburetor) 4-97
4-28 Device 384 Air-Fuel Mixture Diffuser Installation Sketch
(from Developer's Patent Disclosure) 4-99
4-29 Device 33 Carburetor Modification (Main Jet Differential
Pressure) Configuration 4-104
4-30 Device 33 Carburetor Modification (Main Jet Differential
Pressure) Air-Fuel Ratio Test Results (Developer Data) . . . 4-106
4-31 Device 56 Crankcase Blowby and Idle Air Bleed Modification
(Developer Photo) . . . 4-113
4-32 Device 56 Special Air Bleed Idle Jet 4-113
4-33 Device 288 Carburetor Main Discharge Nozzle Modification . . . 4-117
4-34 Device 295 Variable Venturi Carburetor 4-124
4-35 Device 295 Variable Venturi Carburetor Functional Diagram
(Developer Sketch) 4-125
4-36 Device 317 Carburetor Modification With Vacuum Advance
Disconnect Installation (Developer Photo) 4-133
4-37 Device 317 Carburetor Modification With Vacuum Advance
Disconnect: Principal Components (Developer Sketch) .... 4-134
C-9
-------
VOLUME II
ILLUSTRATIONS (CONTINUED)
Figure
5-1 Device 69 Electronic-Controlled Vacuum Advance Disconnect
with Carburetor Lean Idle Modification 5-5
5-2 Device 69 Electronic-Controlled Vacuum Advance Disconnect
Functional Schematic (Developer Sketch) 5-6
5-3 Device 175 Electronic Control Module Installed on Fender
Well 5-13
5-4 Device 259 Photocell-Controlled Ignition System Components
(4-Cylinder Ignition System) 5-25
5-5 Device 259 Photocell-Controlled Ignition System Electrical
Schematic (Developer Sketch) 5-27
5-6 Device 259 Photocell Controlled Ignition System Typical
Installation 5-29
5-7 Device 268 Capacitive Discharge Ignition 5-32
5-8 Device 268 Capacitive Discharge Ignition Schematic
(Developer Sketch) 5-33
5-9 Device 259 Ignition Timing and Spark Modification 5-37
6-1 Device 52 Gaseous Fuel Carburetor Types 6-6
6-2 Device 52 Single-Fuel System Diagram (Reference 35) 6-7
6-3 Device 52 Dual-Fuel System Diagram (Reference 36) 6-7
6-4 Device 52 Single-Fuel System Converter and Carburetor
Diagram (Reference 37) 6-9
6-5 Device 52 Dual-Fuel System Converter and Carburetor Diagram
(Reference 38) 6-9
6-6 Device 52 LPG Conversion Representative Carburetor
(Reference 37) 6-10
6-7 Device 52 Variation of Air-Fuel Ratio with Fuel Pressure
(Engine: Ford 352 CID with Type D - Reference 37) 6-11
6-8 Effect of Air-Fuel Ratio and Spark Advance on LPG
Emissions (Reference 41) 6-14
6-9 Device 52 Single-Fuel LPG Installation (Reference 52) .... 6-25
6-10 Device 459 LPG Conversion System Illustration (Reference 66) . 6-36
6-11 Device 459 Single-Fuel Air Valve Carburetor (Reference 66) . . 6-36
6-12 Device 460 Compressed Natural Gas Dual Fuel Conversion
System Installed on a Chrysler New Yorker (Reference 68) . . 6-49
6-13 CNG Instrument Panel Controls (Reference 103) 6-51
6-14 CNG Dual-Fuel Conversion System Functional Schematic
(Reference 46) 6-51
6-15 Device 282 LP Gas Injection System Components 6-68
6-16 Device 282 LP Gas Injection Functional Schematic 6-68
6-17 Device 279 Fuel Conditioner Functional Schematic (Developer
Data) 6-78
7-1 Device 24 System Components (Developer Drawing) 7-4
7-2 Device 170 Closed Blowby Control System (Developer Drawing). . 7-8
7-3 Device 170 Closed Blowby Control System Adjustable Blowby
Flow and Pressure Relief Valve (Developer Drawing) 7-8
7-4 Device 170 Closed Blowby Control System Adjustment Procedure . 7-12
7-5 Device 170 Closed Blowby Control System Installation
(Developer Photos) „ 7-12
7-6 Device 315 Closed Blowby Control System Installed on
Carburetor 7-16
C-10
-------
VOLUME II
ILLUSTRATIONS (CONTINUED)
7-7 Device 315 Closed Blowby Control System Vent Valve
Configuration (Based on Developer Drawings) 7-16
7-8 Device 315 Slide Mechanism (Based on Developer Drawings) ... 7-17
7-9 Device 160 Closed System with Filter Typical Installation
(Developer Drawings) 7-21
7-10 Device 160 Closed Blowby Control System with Filter: PCV
Valve and Filter Assembly 7-22
7-11 Device 160 Oil-Bath Type Air Cleaner for Open Blowby
Systems (Developer Drawing) 7-22
7-12 Device 427 Closed Blowby Control System Filter-Valve
Assembly 7-27
7-13 Device 427 Closed Blowby Control System Filter-Valve
Assembly Details (Developer Drawing) 7-28
7-14 Device 427 Closed Blowby Control System with Filter
Functional Diagram (Developer Drawing) 7-28
8-1 Absorption-Regenerative Fuel Evaporation Control System . . . 8-2
9-1 Device 165 Exhaust Gas Afterburner/Recirculation with
Blowby and Fuel Evaporation Recirculation Installation . . . 9-6
9-2 Device 165 Exhaust Gas Afterburner/Recirculation with
Blowby and Fuel Evaporation Recirculation Functional
Block Diagram 9-7
9-3 Device 408 Exhaust Gas and Blowby Recirculation with Intake
Vacuum Control and Turbulent Mixing Assembly 9-16
9-4 Device 408 Exhaust Gas and Blowby Recirculation with Intake
Vacuum Control and Turbulent Mixing Components 9-16
9-5 Exhaust Gas Recirculation System 9-22
9-6 Exhaust Particulate Matter Trapping System A . 9-22.
9-7 Cyclone Separator and Collection Box 9-23
C-ll
-------
VOLUME II
TABLES
Table Page
1-1 Type of Vehicle Emission Controls Incorporated on Existing
"Used Cars" at Time of Manufacture 1-3
1-2 Data Survey Results 1-8
2-1 Classification of Retrofit Methods 2-3
3-1 Type 1.1 - Exhaust Gas Control System Retrofit Devices .... 3-2
3-2 Device 96 Catalytic Converter with Vacuum Advance Disconnect
Emission Reduction and Fuel Consumption Performance .... 3-8
3-3 Device 96 Average Emission Reduction Performance . 3-8
3-4 Device 96 Emission Reduction Performance Reported by
Developer 3-9
3-5 Emission Test Results Obtained by EPA on Tricomponent Cata-
lytic Converter Provided by Device 96 Developer . 3-10
3-6 Device 96 Catalytic Converter with Vacuum Advance Disconnect
Driveability Test Results . 3-13
3-7 Device 96 Catalytic Converter with Vacuum Advance Disconnect
Installation Procedure .... 3-15
3-8 Device 96 Catalytic Converter with Vacuum Advance Disconnect
Initial and Recurring Costs 3-18
3-9 Device 292 LPG-Fuel Emission Reduction Performance Reported
by Developer 3-21
3-10 Device 292 Catalytic Converter EPA Emission Test Results with
Auxiliary Air Pump 3-21
3-11 Device 292 Catalytic Converter Emission Reduction Reliability
Reported by Developer for 48,300 Miles of Operation .... 3-22
3-12 Device 292 Catalytic Converter Installation Procedure .... 3-24
3-13 Device 292 Catalytic Converter Initial and Recurring Costs . . 3-25
3-14 Device 62 Catalytic Converter EPA Emission Test Results . . . 3-27
3-15 Device 93 Catalytic Converter with Exhaust Gas Recirculation,
Spark Modification, and Lean Idle Mixture EPA Emission
Test Results 3-30
3-16 Composition of Candidate Alloys for Device 244 Rich Thermal
Reactor 3-34
3-17 Device 244 Rich Thermal Reactor Developer Acceleration Test
Results 3-45
3-18 Device 244 Rich Thermal Reactor Developer Fuel Consumption
Test Results 3-46
3-19 Device 244 Rich Thermal Reactor Installation Procedure .... 3-48
3-20 Device 244 Rich Thermal Reactor Initial and Recurring Costs . 3-49
3-21 Device 463 Rich Thermal Reactor Emission Levels Compared to
1975 Standards 3-54
3-22 Device 463 Rich Thermal Reactor Emission Levels Reported by
EPA 3-54
3-23 Device 463 Rich Thermal Reactor Exhaust Backpressure Reported
by Developer 3-55
3-24 Device 463 Rich Thermal Reactor Vehicle Acceleration Time
Increase Reported by Developer 3-55
C-12
-------
VOLUME II
TABLES (CONTINUED)
Table Page
3-25 Device 468 Emission Test Results without Air Injection .... 3-60
3-26 Device 468 Emission Test Results with Air Injection 3-60
3-27 Device 468 LTR-EGR Durability Emission Test Results 3-61
3-28 Device 468 LTR-EGR Fuel Consumption Compared to Conventional
Cars . -.- 3-63
3-29 Device 31 Turbine Blower and Conventional Air Pump System
Emission Test Results (Developer 7-Mode Data) 3-67
3-30 Device 31 Turbine Blower Air Injection System Installation
Procedure 3-70
3-31 Device 31 Turbine Blower Air Injection System Initial and
Recurring Costs 3-72
3-32 Device 308 Exhaust Gas Afterburner Emission Test Results
Reported by Developer 3-75
3-33 Device 308 Exhaust Gas Afterburner Installation Procedure . . 3-77
3-34 Device 308 Exhaust Gas Afterburner Initial and Recurring Costs 3-78
3-35 Device 425 Exhaust Gas Afterburner Emission Test Results
Reported by Developer 3-81
3-36 Device 425 Exhaust Gas Afterburner Installation Procedure . . 3-85
3-37 Device 425 Exhaust Gas Afterburner Initial and Recurring Costs 3-86
3-38 Device 164 Exhaust Gas Filter Emission Test Results Reported
by the Developer 3-91
3-39 Device 164 Exhaust Gas Filter Installation Procedure 3-92
3-40 Device 164 Exhaust Gas Filter Initial and Recurring Costs . . 3-93
3-41 Device 322 Exhaust Gas Backpressure Valve Emission Test
Results 3-95
4-1 Type 1.2 Induction Control System Retrofit Devices 4-2
4-2 Device 1 Air Bleed to Intake Manifold Emission Results
Reported by Developer 4-6
4-3 Device 1 Air Bleed to Intake Manifold Emission Reduction and
Fuel Consumption Performance 4-7
4-4 Device 1 EPA Emission Test Results 4-8
4-5 Device 1 Air Bleed to Intake Manifold Driveability Test
Results 4-9
4-6 Device 1 Air Bleed to Intake Manifold Installation Procedure . 4-10
4-7 Device 1 Air Bleed to Intake Manifold Initial and Recurring
Costs 4-13
4-8 Device 42 Air Bleed to Intake Manifold Emission Reduction and
Fuel Consumption Performance 4-17
4-9 Device 42 Mean Emission Test Results Based on Tests Reported
by Developer 4-17
4-10 Device 42 Air Bleed to Intake Manifold Driveability Test
Results 4-18
4-11 Device 42 Air Bleed to Intake Manifold Installation Procedure. 4-20
4-12 Device 42 Air Bleed to Intake Manifold Initial and Recurring
Costs 4-21
4-13 Device 57 Air Bleed with EGR and Vacuum Advance Disconnect
Emission Test Results Reported by Developer 4-25
4-14 Device 57 Air Bleed with EGR and Vacuum Advance Disconnect
Installation Procedure 4-27
C-13
-------
VOLUME II
TABLES (CONTINUED)
Table • Page
4-15 Device 57 Air Bleed with EGR and Vacuum Advance Disconnect
Initial and Recurring Costs 4-29
4-16 Device 325/433 Air-Vapor Bleed to Intake Manifold Emission
Test Results Provided by Developer 4-34
4-17 Device 325/433 Air-Vapor Bleed to Intake Manifold Average
Percentage Emission Reduction 4-35
4-18 Device 325/433 Air-Vapor Bleed to Intake Manifold Installation
Procedure 4-37
4-19 Device 325/433 Air-Vapor Bleed to Intake Manifold Initial and
Recurring Costs 4-38
4-20 Device 401 Air-Vapor Bleed to Intake Manifold Emission Test
Results Reported by Developer 4-40
4-21 Device 401 Air-Vapor Bleed to Intake Manifold Installation
Procedure 4-41
4-22 Device 401 Air-Vapor Bleed to Intake Manifold Initial and
Recurring Costs 4-42
4-23 Device 418 Air Bleed to Intake Manifold Mean Emission Test
Results 4-44
4-24 Device 458 Air Bleed to Intake Manifold Emission Test Results . 4-45
4-25 Device 462 Air Bleed to Intake and Exhaust Manifolds Mean
Emission Test Results 4-48
4-26 Device 10 Throttle-Controlled EGR with Vacuum Advance Dis-
connect Emission Reduction and Fuel Consumption Performance . 4-52
4-27 Device 10 Throttle-Controlled EGR with Vacuum Advance Dis-
connect Driveability Test Results 4-53
4-28 Device 10 Throttle-Controlled EGR with Vacuum Advance Dis-
connect Installation Procedure 4-55
4-29 Device 10 Throttle-Controlled EGR with Vacuum Advance Dis-
connect Initial and Recurring Costs 4-56
4-30 Device 245 Variable Camshaft Emission Reduction and Fuel Con-
sumption Performance 4-60
4-31 Comparative Emission Test Results for a Device Tested by EPA
with Variable Camshaft Timing, Vacuum Advance Disconnect and
Lean Carburetion 4-61
4-32 Device 245 Driveability Test Results 4-62
4-33 Device 245 Variable Camshaft Timing Installation Procedure . . 4-64
4-34 Device 245 Variable Camshaft Timing Initial and Recurring Costs 4-66
4-35 Device 246 Speed-Controlled EGR with Vacuum Advance Disconnect
Emission Reduction and Fuel Consumption Performance 4-70
4-36 Device 246 Speed-Controlled EGR with Vacuum Advance Disconnect
Emission Test Results Reported by Developer 4-71
4-37 Device 246 Speed-Controlled EGR with Vacuum Advance Disconnect
Emission Test Results Reported by EPA 4-72
4-38 Device 246 Speed-Controlled EGR with Vacuum Advance Disconnect
Driveability Test Results 4-73
4-39 Device 246 Speed-Controlled EGR with Vacuum Advance Disconnect
Installation Procedure 4-75
4-40 Device 246 Speed-Controlled EGR with Vacuum Advance Disconnect
Initial and Recurring Costs 4-78
C-14
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VOLUME II
TABLES (CONTINUED)
Table Page
4-41 Device 294 Emission Test Results 4-79
4-42 Device 172 Intake Manifold Modification Emission Test Results
Reported by Developer 4-82
4-43 Device 172 EPA Emission Test Results 4-82
4-44 Device 172 Intake Manifold Modification Fuel Consumption Data
Reported by Developer 4-83
4-45 Device 172 Intake Manifold Modification Installation Procedure. 4-84
4-46 Device 172 Intake Manifold Initial and Recurring Costs .... 4-85
4-47 Device 430 Induction Modification Emission Test Results Pro-
vided by Developer 4-88
4-48 Device 430 Induction Modification Installation Procedure . . . 4-89
4-49 Device 430 Induction Modification Initial and Recurring Costs . 4-90
4-50 Device 440 Intake Deflection Plate Test Experience Summary
Provided by Developer 4-93
4-51 Device 440 Intake Deflection Plate Installation Procedure . . . 4-95
4-52 Device 440 Intake Deflection Plate Initial and Recurring Costs. 4-96
4-53 Summary of Device 384 Air-Fuel Mixture Diffuser Exhaust
Emission Data Provided by Developer 4-100
4-54 Device 384 Air-Fuel Mixture Diffuser Installation Procedures. . 4-102
4-55 Device 33 Carburetor Modification (Main Jet Differential Pres-
sure) Emission Test Results Reported by Developer 4-107
4-56 Device 33 Carburetor Modification (Main Jet Differential Pres-
sure) Emission Reduction and Fuel Consumption Performance . . 4-107
4-57 Device 33 Carburetor Modification (Main Jet Differential
Pressure) 4-109
4-58 Device 33 Installation Procedure .... 4-109
4-59 Device 33 Initial and Recurring Costs 4-111
4-60 Device 56 Crankcase Blowby and Idle Air Bleed Modification:
Summary of Exhaust Emission Data Reported by Developer . . . 4-114
4-61 Device 56 Installation Procedure 4-115
4-62 Device 56 Initial and Recurring Costs 4-116
4-63 Device 288 Carburetor Main Discharge Nozzle Modification
Emission Reduction and Fuel Consumption Performance 4-118
4-64 Device 288 Summary of Developer-Reported Measurements by
Independent Laboratories 4-119
4-65 Device 288 Carburetor Main Discharge Nozzle Modification
Driveability Test Results 4-120
4-66 Device 288 Carburetor Main Discharge Nozzle Modification
Installation Procedure . 4-121
4-67 Device 288 Carburetor Main Discharge Nozzle Modification
Initial and Recurring Costs 4-122
4-68 Device 295 Variable Venturi Carburetor Emission Reduction and
Fuel Consummation Performance 4-128
4-69 Device 295 Variable Venturi Carburetor Driveability Test
Results 4-129
4-70 Device 295 Variable Venturi Carburetor Installation Procedure . 4-130
4-71 Device 295 Variable Venturi Carburetor Initial and Recurring
Costs 4-131
4-72 Device 317 Emission Test Results Reported by Developer .... 4-135
C-15
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VOLUME II
TABLES (CONTINUED)
Device 317 Carburetor Modification with Vacuum Advance Dis-
connect Installation Procedure 4-137
Device 317 Carburetor Modification with Vacuum Advance Dis-
connect Installation Costs 4-138
4-75 Device 100 Turbocharger Emission Test Results 4-139
4-76 Device 22 Electronic Fuel Injection Emission Test Results
Reported by EPA 4-141
4-77 Device 22 Electronic Fuel Injection Acceleration Results . . . 4-142
5-1 Type 1.3 Ignition Control System Retrofit Devices 5-1
5-2 Device 69 Electronic-Controlled Vacuum Advance Disconnect and
Carburetor Lean Idle Modification Emission Reduction and Fuel
Consumption Performance 5-7
5-3 Device 69 Driveability Test Results 5-8
5-4 Device 69 Electronic-Controlled Vacuum Advance Disconnect and
Carburetor Lean Idle Modification Installation Procedure . . 5-9
5-5 Device 69 Electronic-Controlled Vacuum Advance Disconnect and
Carburetor Lean Idle Modification Initial and Recurring Costs 5-11
5-6 Device 175 Ignition Timing Modification with Lean Idle Adjust-
ment Emission Test Results Submitted by Developer 5-14
5-7 Device 175 Ignition Timing Modification with Lean Idle Adjust-
ment Emission Reduction and Fuel Consumption Performance . . 5-15
5-8 Device 175 Driveability Test Results 5-17
5-9 Device 175 Installation Procedure 5-18
5-10 Device 175 Initial and Recurring Costs 5-19
5-11 Device 23 Electronic Ignition Unit Emission Test Results Re-
ported by HEW/NAPCA 5-22
5-12 Device 95 Ignition Spark Modification Emission Test Results . . 5-23
5-13 Device 95 Emission Test Results 5-24
5-14 Device 259 Photocell-Controlled Ignition System Installation
Procedure 5-30
5-15 Device 259 Photocell-Controlled Ignition System Initial and
Recurring Costs 5-31
5-16 Device 268 Capacitive Discharge Ignition Installation Procedure 5-34
5-17 Device 268 Capacitive Discharge Ignition Initial and Recurring
Costs 5-35
5-18 Device 296 Ignition Timing and Spark Modification Emission Test
Results Reported by Developer ..... 5-38
5-19 Device 296 Ignition Timing and Spark Modification Installation
Procedure 5-39
5-20 Device 296 Ignition Timing and Spark Modification Initial and
Recurring Costs 5-39
6-1 Type 1.4 Fuel Modification Retrofit Devices 6-2
6-2 Device 52 LPG Conversion Emission Test Results with 1968 Buick
Skylark 6-12
6-3 Device 52 LPG Conversion Emission Test Results with Vacuum
Advance Disconnect and Retarded Timing on 1970 Falcons and
Rebels ..... 6-12
6-4 Device 52 Emission Test Results with Ford Fairlane and
Mustang 6-13
C-16
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VOLUME II
TABLES (CONTINUED)
6-5 Device 52 LPG Conversion Emission Data Obtained by California
Gaseous Fuel Test Procedure 6-15
6-6 Device 52 LPG Conversion Vehicle Maintenance Cost
Comparison 6-17
6-7 Device 52 LPG Conversion Acceleration Test Results with Spark
Retard and Vacuum Advance Disconnected 6-18
6-8 Device 52 LPG Conversion Fuel Consumption Comparison 6-19
6-9 Device 52 LPG Conversion Installation Procedure 6-21
6-10 Device 52 LPG Conversion Initial and Recurring Costs for
Typical Conversion to Meet Emission Standards 6-26
6-11 Device 466 LPG Gasoline Dual-Fuel Conversion Emission Test
Results 6-32
6-12 Device 466 Exhaust Hydrocarbon Composition by Subtractive
Column Analysis 6-32
6-13 Device 466 Emission Test Results 6-33
6-14 Device 459 LPG Conversion with Deceleration Unit Emission Test
Results 6-37
6-15 Device 461 Emission Test Results 6-40
6-16 Device 464 Emission Test Results 6-44
6-17 Compressed Natural Gas Tank Characteristics 6-48
6-18 Device 460 Compressed Natural Gas Dual-Fuel Conversion Emission
Test Results 6-50
6-19 Device 460 CNG Dual-Fuel Conversion Emission Test Results . . . 6-52
6-20 Device 460 CNG Hydrocarbon Reactivity 6-52
6-21 Device 460 Acceleration Test Results with a 1971 Ford
Mustang 6-55
6-22 Device 460 CNG Dual-Fuel Conversion Initial and Recurring
Costs 6-57
6-23 Device 182 Fuel and Oil Additives Emission Test Results
Reported by City of Los Angeles 6-62
6-24 Device 182 Fuel and Oil Additives Emission Test Results
Reported by Olson Laboratories 6-62
6-25 Device 182 Fuel Consumption Reduction Reported by McDonnell
Douglas Aircraft Division 6-63
6-26 Device 182 Fuel and Oil Additives Initial and Recurring Costs . 6-64
6-27 Device 465 Emission Test Results 6-66
6-28 Device 282 LP Gas Injection Installation Procedure ...... 6-71
6-29 Device 282 LP Gas Injection Initial and Recurring Costs .... 6-72
6-30 Device 36 Fuel Conditioning by Exposure to Electromagnetic Field
Emission Test Results 6-77
6-31 Device 279 Fuel Conditioner Emission Test Results Reported by
Developer 6-79
6-32 Device 279 Fuel Conditioner Installation Procedure 6-80
6-33 Device 279 Initial and Recurring Costs 6-81
7-1 Group 2 Crankcase Emission Control Systems 7-2
7-2 Device 24 Heavy Duty Positive Crankcase Control Valve with Air
•Bleed Exhaust Emission Test Results Reported by EPA 7-4
7-3 Device 24 Heavy Duty Positive Crankcase Ventilation with Air
Bleed Initial and Recurring Costs 7-5
C-17
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VOLUME II
TABLES (CONTINUED)
Table
7-4 Device 170 Closed Blowby Control System Exhaust Emission Test
Results 7-10
7-5 Device 170 Closed Blowby Control System Installation
Procedure 7-13
7-6 Device 170 Closed Blowby Control System Initial and Recurring
Costs 7-14
7-7 Device 315 Closed Blowby Control System Exhaust Emission Test
Results Reported by Developer 7-18
7-8 Device 315 Closed Blowby Control System Installation
Procedure 7-19
7-9 Device 315 Closed Blowby Control System Initial and Recurring
Costs . , 7-20
7-10 Device 160 Closed or Open Blowby Control System with Filter
Emission Test Results Reported by Developer 7-23
7-11 Device 160 Closed Blowby Control System with Filter Installa-
tion Procedure 7-25
7-12 Device 160 Closed Blowby Control System with Filter Initial and
Recurring Costs 7-26
7-13 Device 427 Closed Blowby Control System with Filter Exhaust
Emission Reduction Performance 7-29
7-14 .Device 427 Closed Blowby Control System with Filter Drive-
ability Results Reported by Developer 7-30
7-15 Device 427 Closed Blowby Control System with Filter Installa-
tion Procedure 7-32
7-16 Device 427 Closed Blowby Control System with Filter Initial
and Recurring Costs 7-33
8-1 Device 467 Absorption-Regenerative Fuel Evaporation Control
System Installation Procedure ..... 8-4
8-2 Device 467 Absorption-Regenerative Fuel Evaporation Control
System Initial and Recurring Costs 8-5
9-1 Group 4 Emission Control Combination Retrofit Devices 9-1
9-2 Device 59 Three-Stage Exhaust Gas Control System Emission
Test Results 9-2
9-3 Device 59 Three-Stage Exhaust Gas Control System Driveability . 9-3
9-4 Device 165 Exhaust Gas Afterburner/Recirculation with Blowby
and Fuel Evaporation Recirculation Exhaust Emission Test
Results 9-8
9-5 Device 165 Exhaust Gas Afterburner/Recirculation with Blowby
and Fuel Evaporation Recirculation Driveability 9-9
9-6 Exhaust Gas Afterburner/Recirculation with Blowby and Fuel
Evaporation Recirculation Installation Procedure 9-11
9-7 Exhaust Gas Afterburner/Recirculation with Blowby and Fuel
Evaporation Recirculation Initial and Recurring Cost .... 9-13
9-8 Device 408 Exhaust Gas and Blowby Recirculation with Intake
Vacuum Control and Turbulent Mixing Driveability 9-18
9-9 Device 408 Exhaust Gas and Blowby Recirculation with Intake
Vacuum Control and Turbulent Mixing Installation
Procedure 9-19
C-18
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VOLUME II
TABLES (CONTINUED)
Table Page
9-10 Device 408 Exhaust Gas and Blowby Recirculation with Intake
Vacuum Control and Turbulent Mixing Initial and Recurring
Costs 9-20
9-11 Device 469 Emission Reduction Results Cold 9 Cycle CVS .... 9-24
C-19
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VOLUME III
TABLE OF CONTENTS
Section Page
FOREWORD iii
ACKNOWLEDGMENTS v
GLOSSARY vi
1 INTRODUCTION 1-1
1.1 Evaluation Objectives 1-1
1.2 Evaluation Approach 1-2
1.3 Evaluation Conclusions 1-2
2 RETROFIT METHOD APPLICABILITY TO USED CAR EMISSION CONTROL . . 2-1
2.1 The Impact of Retrofit Controls on Used Vehicles . . 2-1
2.2 Retrofit System Emission Control Capability 2-2
3 EVALUATION METHODOLOGY 3-1
3.1 The Criteria Index 3-2
3.1.1 Emission Standards Factor 3-4
3.1.2 Emission Baseline Factor 3-4
3.1.3 Safety Factor 3-4
3.1.4 Critical Driveability Factor ... 3-5
3.1.5 General Driveability Factor 3-5
3.1.6 Installation Cost Factor 3-6
3.1.7 Recurring Cost Factor 3-6
3.1.8 Reliability Factor 3-6
3.1.9 Maintainability Factor 3-6
3.1.10 Availability Factor 3-7
3.2 Performance Index 3-7
3.2.1 Emission Index 3-8
3.2.2 Driveability Index 3-9
3.2.3 Cost Index 3-10
3.3 Cost Effectiveness Index 3-12
3.4 Establishing Weighting Coefficients for the
Performance Index 3-12
4 RETROFIT PERFORMANCE ANALYSIS 4-1
4.1 Engineering Analysis 4-1
4.1.1 Engineering Analysis Team 4-1
4.1.2 Engineering Analysis Approach 4-2
4.2 Test Program 4-4
4.2.1 Test Vehicle Fleet 4-4
4.2.2 Selection of Retrofit Test Devices 4-8
4.2.3 Test Approach 4-8
4.2.4 Test Procedures 4-12
4.3 Performance Analysis Data Inputs and Results .... 4-13
C-21
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VOLUME III
CONTENTS (CONTINUED)
Section Page
5 CRITERIA INDEX ANALYSIS 5-1
5.1 Evaluation Criteria 5-1
5.2 Criteria Index Results 5-1
5.3 Retrofit System Feasibility 5-5
6 PERFORMANCE INDEX ANALYSIS 6-1
6.1 Emission Reduction Results . . . . 6-1
6.1.1 Device 1: Air Bleed to Intake Manifold 6-8
6.1.2 Device 96: Catalytic Converter with Vacuum
Advance Disconnect 6-9
6.1.3 Device 175: Ignition Timing Modification with
Lean Idle Adjustment 6-11
6.1.4 Device 246; Exhaust Gas Recirculation with Vacuum
Advance Disconnect 6-11
6.1.5 Emission Reduction Versus Engine Size 6-12
6.1.6 Emission Index Results 6-12
6.2 Driveability Index 6-12
6.2.1 Driveability Index Results 6-15
6.2.2 Driveability Index Sensitivity Analysis 6-18
6.3 Cost Index 6-18
6.3.1 Initial Costs 6-19
6.3.2 Recurring Costs 6-19
6.3.3 Cost Index Results 6-20
6.3.4 Cost Index Sensitivity Analysis 6-22
6.4 Performance Index 6-23
6.4.1 Performance Index Results 6-24
6.4.2 Weighting Coefficient Sensitivity Analysis 6-24
7 COST EFFECTIVENESS INDEX 7-1
7.1 Cost Effectiveness Results 7-1
8 GUIDELINES FOR SELECTING AND IMPLEMENTING RETROFIT METHODS . . 8-1
8.1 Defining the Required Emission Reduction 8-2
8.2 Defining the Uncontrolled Vehicle Population .... 8-2
8.3 Identifying Candidate Retrofit Methods 8-3
8.4 Determining Cost Effective Retrofit Methods 8-5
8.5 Defining the Certification Program 8-7
8.6 Cost Effectiveness Studies of Alternative Control
Programs 8-8
8.7 Preparing an Implementation Plan 8-8
8.8 Implementing the Plan 8-9
9 RECOMMENDATIONS 9-1
10 REFERENCES 10-1
C-22
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VOLUME III
CONTENTS (CONTINUED)
Appendix Page
A Baseline Exhaust Emissions for Test Vehicles Prior to Each
Retrofit Test (1972 Federal Test Procedure Grams/Mile) . . . A-l
B-l Retrofit Program Test Schedule B-l
B-2 Retrofit Program Test Summary Versus Contract Requirements . . B-l
C Devices Evaluated in Retrofit Program C-l
D Performance Analysis Input Data D-l
E Computer Analysis Results E-l
F Baseline and Retrofit Emission Levels in Grams/Mile for
Devices Tested in Retrofit Program by 1972 Federal Test
Procedure F-l
G Mean Emission Levels for Retrofit Devices Evaluated Based
on EPA and Retrofit Developer Test Data G-l
H Welch's Approximate t Solution of the Fisher-Behrens Problem . H-l
J Sensitivity Analysis of Retrofit Program Driveability and
Cost Indexes J-l
K Cost Index Results for Retrofit Devices with Cost Data .... K-l
L Fuel Consumption Measured During the 1972 Test for Devices
Tested in the Retrofit Program L-l
ILLUSTRATIONS
Figure Page
2-1 Sources and Quantities of Emissions from an Uncontrolled
Vehicle 2-3
4-1 Baseline and Retrofit System Test Sequence for Each Test
Vehicle 4-11
6-1 Mean Percentage Emission Reduction and 90 Percent Confidence
Limits for Exhaust Emission Control Retrofit Systems Tested
at Anaheim, California, and Taylor, Michigan 6-9
8-1 Typical Example of Program Management Structure for Periodic
Vehicle Inspection Program . . 8-10
C-23
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VOLUME III
TABLES
Table Page
2-1 Estimated Percentage of Vehicle Population that Could be
Retrofitted with Emission Control Systems 2-3
2-2 Potential Pollutant Control Capability of Retrofit Methods by
Generic Groups 2-5
3-1 Performance Parameters and Evaluation Criteria 3-3
3-2 Weighting Coefficients for the Performance Index 3-14
4-1 Test Vehicle Fleet 4-5
4-2 Test Fleet Exhaust Emissions 4-6
4-3 Taylor vs Anaheim Test Vehicle Baseline Emission Level
Differences in Mean Grams/Mile (Based on Appendix A) 4-9
4-4 Retrofit Devices Selected for Test Programs 4-10
5-1 Criteria Index Results for Devices Evaluated in Retrofit Program . 5-2
6-1 Percentage Emission Reduction of Devices Tested in Retrofit
Program 6-3
6-2 Average Percentage Exhaust Emission Reduction by Test
Procedure for Devices Evaluated in Retrofit Program 6-6
6-3 Discriminatory Power of t Tests 6-8
6-4 Mean Percentage Emission Reduction and 90 Percent Confidence
Intervals for Exhaust Emission Control Retrofit Systems
Tested at Anaheim, California and Taylor, Michigan 6-9
6-5 Rank Ordered Emission Index Values by Test Method for Retrofit
Devices Evaluated 6-13
6-6 Weighting Factors Used for General Driveability Index
Calculations 6-15
6-7 Driveability Index Results in Rank Order for Devices Tested in
Retrofit Program 6-16
6-8 Sensitivity Analysis Calculation for the Driveability Index . . . 6-18
6-9 Average Fuel Mileage Change for Exhaust Emission Control
Retrofit Systems Tested at Anaheim, California, and Taylor,
Michigan 6-20
6-10 Cost Index in Order of Rank for Retrofit Devices with Cost Data . 6-21
6-11 Cost Index Sensitivity Analysis Results 6-23
6-12 Mean Performance Index Results in Rank Order for Devices Tested
in Retrofit Program 6-25
6-13 Performance Index with Alternate Weighting Coefficients for
Devices Tested in Retrofit Program 6-27
7-1 Cost Effectiveness Index in Order of Rank for Retrofit Devices
with Cost and Emission Data 7-3
8-1 Light Duty Vehicle Population and Type of Emission Control .... 8-4
8-2 Performance Parameters and Evaluation Criteria 8-6
C-24
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VOLUME IV
CONTENTS
Section Page
FOREWORD iii
ACKNOWLEDGMENTS ...... v
GLOSSARY . o .... o ..... vi
1 INTRODUCTION 1-1
1.1 Program Objectives ...<>... 1-1
1.2 Program Approach „... 1-1
1.3 Program Schedule 1-2
1.4 Program Organization 1-3
2 RETROFIT METHOD SURVEY . 2-1
2.1 Survey Approach ............... 2-1
2.2 Recording System .................... 2-4
2.3 Retrofit Method Classification System .......... 2-5
3 SYSTEM TESTS „ 3-1
3.1 Identification of Candidate Retrofit Systems for Test . . 3-2
3.2 Test Vehicle Selection . 3-3
3.3 Retrofit Device Emission Tests ....... 3-9
3.4 Driveability Tests 3-10
3.5 Durability Tests ........... 3-12
3.6 Facilities 3-14
4 SYSTEM DESCRIPTIONS 4-1
4.1 System Description Outline 4-1
4.2 Approach to Performance Parameter Analyses . . 4-4
5 PERFORMANCE ANALYSIS ........ . . 5-1
5.1 Performance Index Equation 5-1
5.2 Methodology Implementation 5-3
Appendix
A Request for Retrofit Source Identification A-l
B Letter of Inquiry to Retrofit Developers B-l
C-25
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VOLUME IV
CONTENTS (CONTINUED)
Appendix Page
C News Release C-l
D Retrofit Data Questionnaire and Transmittal Letter D-l
E Excerpts from California Health and Safety Code Applicable
to Retrofit Methods for Vehicle Emission Control E-l
F California Blowby Device Test Procedure F-l
G AMA Driveability Procedure G-l
H Computer Program Printout for Analytical Methodology H-l
ILLUSTRATIONS
Figure Page
1-1 Program Approach to Determining Effectiveness and
Costs of Retrofit Methods 1-2
1-2 Program Master Schedule 1-3
1-3 Program Organization Structure 1-4
2-1 Data Survey Record Sheet ' 2-4
3-1 Test Vehicle Procurement Screening Data Sheet 3-6
3-2 Representative Test Vehicles 3-7
3-3 Baseline and Retrofit System Test Sequence for
Each Test Vehicle 3-11
3-4 Los Angeles Durability Test Route 3-13
3-5 Daily Shift Record for Durability Test 3-15
3-6 Vehicle Emission Test Facility at Anaheim, California . 3-16
3-7 Driveability Test Area 3-16
3-8 Olson Laboratories Emission Test Equipment 3-17
5-1 Retrofit Information Flow to Computer 5-5
5-2 Exhaust Emissions Computer Input Sheet 5-6
5-3 Driveability Test Data Input Sheet 5-7
5-4 Retrofit Device Data-Input Form 5-8
5-5 Computer Program Top Level Flow Chart 5-10
TABLES
Table Page
2-1 Retrofit Method Program News Release Mailing List 2-3
2-2 Classification of Retrofit Methods ... 2-6
3-1 Test Vehicle Fleet 3-6
3-2 Retrofit Test Vehicle Service and Tuneup Procedure 3-8
3-3 Durability Test Route 3-14
3-4 Durability Test Mileage Accumulation Schedule 3-14
4-1 Retrofit Method Performance Parameter Evaluation Matrix 4-2
. 4-2 Device No. Performance Characteristics 4-3
4-3 Installation Procedures: Device No. 4-6
4-4 Installation Cost: Device No. 4-7
5-1 Performance Parameters and Evaluation Criteria 5-4
C-26
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VOLUME V
CONTENTS
Appendix Page
FOREWORD o«.. iii
ACKNOWLEDGMENTS v
GLOSSARY ........ vi
V-l DATA SURVEY RESULTS . „ . V-l-1
V-2 INVENTORY OF RETROFIT SOURCE DATA V-2-1
V-3 DATA SURVEY: QUESTIONNAIRE RESPONSES ............ V-3-1
V-4 ALPHABETICAL INDEX - DEVELOPMENT SOURCES OF RETROFIT
DEVICES EVALUATED . . . V-4-1
C-27
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VOLUME VI
CONTENTS
Section Page
FOREWORD „ , iii
ACKNOWLEDGMENTS „ „ v
GLOSSARY o vi
1 SUMMARY AND CONCLUSIONS 1-1
1.1 Summary of Test Results 1-1
1.2 Conclusions (1)
2 INTRODUCTION 2-1
2.1 Background 2-1
2.2 Objectives (1)
3 DURABILITY TEST PROGRAM 3-1
3.1 Test Vehicles 3-1
3.2 Description of Devices .......... (1)
3.3 Vehicle Preparation and Maintenance ........... (1)
3.4 Device Installation and Maintenance (1)
3.5 Test Route and Driving Schedule (1)
3.6 Emission Test Procedures . (1)
4 TEST RESULTS AND DISCUSSION 4-1
4.1 Test Results 4-1
4.2 Discussion of Results (1)
Appendices (1)
(1) Missing page numbers were not established at the time of printing of this
volume; Volume VI to be published shortly.
C-29
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