EPA-AA-TAEB 76-29
Exhaust Emissions and Fuel Economy
of a Vehicle Equipped with the
Hausknecht Valve Train Modification
September 1976
Technology Assessment and Evaluation Branch
Emission Control Technology Division
Office of Mobile Source Air Pollution Control
U. S. Environmental Protection Agency
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Background
The Environmental Protection Agency receives information about many
devices for which emission reduction or fuel economy improvement claims
are made. In some cases, both claims are made for a single device. In
most cases, these devices are being recommended or promoted for retrofit
to existing vehicles although some represent advanced systems for meeting
future standards.
The EPA is interested in evaluating the validity of the claims for all
such devices, because of the obvious benefits to the Nation of identifying
devices that live up to their claims. For that reason the EPA invites
proponents of such devices to provide to the EPA complete technical data
on the device's principle of operation, together with test data on the
device made by independent laboratories. In those cases in which review
by EPA technical staff suggests that the data submitted holds promise of
confirming the claims made for the device, confirmatory tests of the
device are scheduled at the EPA Emissions Laboratory at Ann Arbor,
Michigan. The results of all such confirmatory test projects are set
forth in a series of Technology Assessment and Evaluation Reports, of
which this report is one.
The conclusions drawn from the EPA confirmatory tests are necessarily of
limited applicability. A complete evaluation of the effectiveness of an
emission control system in achieving its claimed performance improvements
on the many different types of vehicles that are in actual use requires
a much larger sample of test vehicles than is economically feasible in
the confirmatory test projects conducted by EPA. _!/ For promising
devices it is necessary that more extensive test programs be carried
out.
The conclusions from the EPA confirmatory tests can be considered to be
quantitatively valid only for the specific type of .vehicle used in the
EPA confirmatory test program. Although it is reasonable to extrapolate
the results from the EPA confirmatory test to other types of vehicles in
a directional or qualitative manner, i.e., to suggest that similar
results are likely to be achieved on other types of vehicles, tests of
the device on such other vehicles would be required to reliably quantify
results on other types of vehicles.
In summary, a device that lives up to its claims in the EPA confirmatory
test must be further tested according to protocols described in footnote
JY, to quantify its beneficial effects on a broad range of vehicles. A
device which when tested by EPA does not meet the claimed results would
not appear to be a worthwhile candidate for such further testing from
the standpoint of the likelihood of ultimately validating the claims
made. However, a definitive quantitative evaluation of its effective-
ness on a broad range of vehicle types would equally require further
tests in accordance with footnote I/.
_!/ See Federal Register 38 FR 11334, 3/27/74, for a description of the
test protocols proposed for definitive evaluations of the effectiveness
of retrofit devices.
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One system brought to the attention of the EPA is the Hausknecht valve
train modification. The Hausknecht modification employs a hydraulic
system to control the opening and closing of the intake valve. By
suitable control of the hydraulic system, the timing of the intake valve
opening can be varied.
The intent of the Hausknecht modification is to improve vehicle fuel
economy by varying the valve timing to suit the engine operating con-
ditions.
Test Vehicle Description
The Hausknecht modification was made to a 1965 Chevrolet equipped with a
350 cu in. engine and a two-speed automatic transmission. The original
engine had been removed from the vehicle and replaced with a 1973
Chevrolet engine. The remainder of the vehicle was not modified. A
listing of vehicle specifications is given on the vehicle description
sheet following the text of this report. The vehicle was tested at an
inertia weight of 4000 Ibs.
The Hausknecht modification employs hydraulic actuation of the intake
valves. The exhaust valves are actuated in a conventional manner, by
means of mechanical linkage between the camshaft and valve. For the
intake valves, the camshaft operates a master piston in a hydraulic
system which in turn operates a slave piston that opens the intake
valve. A control system is used to regulate the volume of the hydraulic
system. By manipulation of the control system, the timing of the opening
of the intake valve and the duration of the opening can be varied to
suit different engine operating modes. The control for the hydraulic
system is connected to the engine throttle linkage.
Test Program
Exhaust emission and fuel economy tests were conducted in accordance
with the 1975 Federal Test Procedure ('75 FTP) for light-duty vehicles
(Federal Register, June 30, 1975, Vol. 40 No. 126, Part III). Emissions
and fuel economy were also measured during the EPA Highway Fuel Economy
Test (HFET) and at selected steady state speeds.
The vehicle was tested twice according to the '75 FTP and HFET. Steady
state emission and fuel economy measurements were made at idle, 30 40,
50 and 60 mph. Duplicate steady state tests were conducted at 40, 50
and 60 mph.
Acceleration time from 0-60 mph was measured on a chassis dynamometer. A
short road test to evaluate driveability was also conducted.
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Test Results
Exhaust emission and fuel economy data are summarized in the following
tables.
1975 Federal Test Procedure
mass emissions in
grams per mile
(grams per kilometer)
Average of
2 tests
HC
8.12
(5.05)
CO
59.2
(36.8)
NO Fuel Economy
(Fuel Consumption)
4.30 13.4 miles/gal.
(2.67) (17.7 liters/100 km)
Average of
2 tests
HC
1.65
(1.03)
Highway Fuel Economy Test
mass emissions in
grams per mile
(grams per kilometer)
CO
14.0
(8.7)
NO
4.83
(3.00)
Fuel Economy
(Fuel Consumption)
19.1 miles/gal
(12.4 liters/100km)
Individual '75 FTP, HFET and steady state test data are presented in
Tables I-IV following the text of this report.
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The exhaust emission levels achieved by the test vehicle are comparable
to the emission levels of vehicles manufactured before Federal control
of exhaust emissions (pre-1968). It is not possible to compare the fuel
economy of the test vehicle to pre-1968 vehicles because of a lack of
data on vehicles of that age. However, the emissions and fuel economy
can be compared to current model vehicles. A 1976 Chevrolet Camaro
equipped with a 350 cu in. engine and using current emission control
technology, has a '75 FTP fuel economy of 14 miles/gal, and a HFET
economy of 18 miles/gal. The Camaro was tested at an inertia weight of
4000 Ibs. 1976 vehicles are designed to meet Federal emission standards
of 1.5 gm/mile HC, 15.0 gm/mile CO and 3.1 gm/mile NOx.
Based on an average of three runs, the 0-60 mph acceleration time of the
Hausknecht vehicle is 11.8 seconds.
A short test drive revealed no significant driveability faults.
Conclusions
The Hausknecht modified vehicle demonstrated fuel economy similar to
that of a comparable 1976 model vehicle. The exhaust emissions from the
Hausknecht vehicle are similar to those of vehicles manufactured prior
to the introduction of Federal emission standards, and much higher than
the 1973 Federal standards of 3.0 gm/mile HC, 28 gm/mile CO and 3.1 gm
(equivalent standards, 1975 FTP), which the unmodified engine was de-
signed to meet.
The disadvantages of the Hausknecht modification include added com-
plexity and cost compared to conventional valve actuation systems.
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Table I
1975 Federal Test Procedure
mass emissions in
grams per mile
(grams per kilometer)
Test #
77-4040
77-4039
Average
HC
CO
CO,
NO
miles/gal.
(liters/100 km)
7.37
(4.58)
8.87
(5.51)
8.12
(5.05)
64.7
(40.2)
53.7
(33.4)
59.2
(36.8)
544.
(338.)
550.
(342.)
547.
(340.)
4.20
(2.61)
4.40
(2.73)
4.30
(2.67)
13.3
(17.7)
13.4
(17.6)
13 JT
(17.7)
Table II
Highway Fuel Economy Test
mass emissions in
grams per mile
(grams per kilometer)
Test #
77-4041
77-4042
Average
HC
1.59
(0.99)
1.70
(1.06)
1.65
(1.03)
CO
13.7
(8.5)
14.2
(8.8)
14.0
(8.7)
co2
444.
(276.)
433.
(269.)
439.
(273.)
NO
X
4.57
(2.84)
5.08
(3.15)
4.83
(3.00)
miles
(liters
18.9
(12.5)
19.3
(12.2)
19.1
(12.4)
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Table III
'75 FTP Individual bag emissions in grams per mile
Bag 1: Cold Transient Bag 2: Stabilized Bag 3: Hot Transient
Test # HC NOx C02 CO MPG HC NOx C02 CO MPG HC NOx C02 CO MPG
77-4040 10.83 5.62 559. 75.9 12.5 7.31 3.13 539. 76.0 13.0 4.89 5.16 542. 34.8 14.5
77-4039 9.93 5.94 559. 60.9 12.9 10.69 3.26 554. 60.7 13.0 4.59 5.40 536. 35.0 14.7
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Table IV
Steady State Mass Emissions in
grams per mile
(grams per kilometer)
HC
CO
CO,
NO
Idle (drive) 66.26 gms/hr 1190gm/hr 5208gm/hr 6.54gm/hr
30mph(48kph)
40mph(64kph)
50mph(81kph)
60mph(97kph)
miles/gal.
(liters/100 km)
1.2gal./hr
6.75
(4.19)
0.86
(0.53)
3.14
(1.95)
0.88
(0.55)
0.76
(0.47)
0.46
(0.29)
0.39
(0.24)
19.2
(11.9)
9.3
(5.8)
12.3
(7.6)
16.9
(10.5)
12.5
(7.8)
5.5
(3.4)
3.3
(2.1)
363.
(225.)
409.
(254.)
384.
(239.)
409.
(254.)
404.
(251.)
455.
(283.)
448.
(278.)
0.97
(0.61)
1.37
(0.85)
0.80
(0.50)
3.19
(1.98)
1.73
(1.08)
5.11
(3.17)
3.47
(2.15)
21.4
(11.0)
20.8
(11.3)
21.5
(11.0)
20.3
(11.6)
20.8
(1.1.3)
19.1
(12.3)
19.5
(12,0)
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8
TEST VEHICLE DESCRIPTION
Chassis model year/make - i965 Chevrolet Biscayne
Emission control system - Variable Intake Valve Timing Installed
in 1973 Chevrolet Engine
Engine
type 4 stroke, Otto cycle, V-8, ohv
bore x stroke 4.00 x 3.48 in/101.6 x 88.4mm
displacement 350 cu in./5737cc
compression ratio 9.0:1
fuel metering carburetor, 4 Venturis
fuel requirement regular leaded
Drive Train
transmission type 2 speed automatic
final drive ratio . 3.08:1
Chassis
type . . . . .... . . front engine, rear wheel drive
tire size . 195R x 14
curb weight ........... 3910 Ibs./1774kg
inertia weight . . . . ... . . . 4000 Ibs.
passenger capacity 6
durability accumulated on system. .40000mi./64400km
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