EPA-AA-TEB 68-1
Exhaust Emissions from
Texaco Combustion Process (TCP)
Stratified Charge Engine
August 1968
Emission Control Engineering Branch
Division of Motor Vehicle"Pollution Control
National Air Pollution Control Administration
Department of Health, Education, and Welfare
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(1)
Subject; TCP Jeep Test Program Results
The exhaust emission characteristics of an engine operating on the
TCP (Texaco Combustion Process) were desired in comparison to the
same basic engine operating in the conventional fashion.
To obtain this comparison, exhaust emissions vere measured from a
TCP engine installed in a M-151-1A ton Army jeep and from a standard
engine in a similar vehicle. Tests were conducted on the chassis
dynamometer and on the road. Two different fuels were used with the
TCP jeep and tests were made after both hot and cold starts for both jeeps
The standard L-lUl engine* had been modified to incorporate the re-
quired features for operation on the stratified charge, multi-fuel
Texaco Combustion Process. This system utilizes high pressure cylinder
injection of the fuel in conjunction with spark ignition. No throttling
of inlet air is required and load control is accomplished by control
of the injected fuel quantity only. Fuels ranging in ignition quality
from DF2 to 115/1^5 aviation gasoline may be used although engine
operating parameters have been optimised for automotive combat gasoline
.(MIL-G-3056-B). For thasa series of teats. CIT3 fuel (MJL-P-45121B) ;;'
end indolene 30 were used.
The following tests were conducted on the two jeeps:
1^ Federal Procedure for exhaust emissions using gasoline fuels
only (indolene 30)•
2) Steady-state speed conditions with each test fuel to obtain
detailed information on exhaust gas composition and photo-
chemical reactivity potential.
3) Investigation of emission and smoke behavior under transient
operation.
M Road tests over composite route. •'.:..
Emission values were obtained both on a concentration basis and on a
mass basis.
Table 1 lists the variables selected for each of the If tests performed.
*Four Cylinder - 3-7/8" Bore 3" Stroke - 141.5 CID
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• 2 -
The California seven-mode cycle was used for all dynamometer tests except
the steady-state speed runs. In eddition to the continu6us recording in-
, strumentation used with the California cycle, mass emissions were measured
using the variable dilution stream splitter. Also, at this time, samples
wera taken for chemical analysis and carburetor air flow measurements were
made. ;
All hydrocarbon, carbon monoxide and carbon dioxide measurements were
obtained using KBIR inatrirnent0. The Saltrman technique was used for
determination of oxides of nitrogen in the mass sampler bags.
Dynamometer Emissions
Haas emission results for the dynamometer tests of the TCP Jeep and standard
jeep appear in Figure 2.
The mass emission figures were obtained from Variable dilution mass sampler
data and are presented in grams/mile units.
The results of the dynamometer evaluation based on mass emissions clearly
show that tha TCP jeep engine reduces carbon monoxide in comparison to a
standard jesp. However, the hydrocarbon emissions for the TCP jeep ware
higher than the standard jeep hydrocarbon emissions*
The effects of dilution with an unthrottled air engine, as in the TCP jeep,
leads to extremely high air-fuel ratios. This fact means that comparison
of seven-mode cycle data on a concentration basis becomes quite difficult,
primarily because the correction factor that must be applied as specified
in the Federal Standards becomes quite large due to the low concentrations
of CO and COg and results in biased hydrocarbon valves.
The intent of the correction factor is to compensate for any dilution of the
exhaust products. Using this correction procedure appears to bias exhaust
gas hydrocarbon results when air-fuel ratio ia changed.(1) Because of this
the correction factor was not applied to the data and the concentration valves
shown in Table 3 were calculated using the measured exhaust concentrations and
revised weighting factors.
See M. W. Jackson, ET. AC, The Influence of Air-Fuel Ratio, Spark Timing,
and Combustion Chamber Deposits on Exhaust Hydrocarbon Emissions.
SAE ^86A, March.1962, Appendix D
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- 3 -
The TCP jeep results ware determined using weighting factors modified to
match the air flox* characteristics of the TCP jeep engine. Because of the
difference in exhaust flow from the TCP engine, it would not bs equitable
to reduce the emission data by use of the normal weighting factors designed
for a throttled-air reciprocating engine. The new weighting factors were
calculated by the procedure originally used by the State of California.
The original mode breakdown and percent of total vbiume in each mode is the
product of the percent time in mode and the average engine air flow in each
mode. The final weighting factors were obtained by combining the percent
of total volumes in each mode in the manner used by the State of California
in the design of the original seven-mode cycle. (For further details see
"The California Motor Vehicle Emissions Standards" by G. C0 Kass SAS paper
number 21QA, August 1960.) The weighting factors used for the TCP engine
are:
Idle .09U
0-25 «"ph o!39
30 .099
30-15 .197
15 .081
15-30 .292
; >;• ;•'.-.. 50-20 . • .098 r ••_. - -.;. ;
The concentration values shown in Table 3 do not reflect the relative exhaust
flow rates of the two jeeps. For this reason, the mass emission data presentee
in Table 2 provides a much more reasonable basis for vehicle emission compariax
Road Results
Emission results from the road tests using the proportional sampler are
shown in Tables h and 5- Table U presents the bag concentrations as they
were measured from the proportional sampler, These values follow closely
the concentrations measured on the dynamometer* Table 5 presents the mass
emissions calculated frcni the proportional sampler data and can be compared
with dynamometer data in Table 2.
The road results compare favorably with the dynamometer testing and
substantiate that the TCP jeep significantly reduced CO emissions compared
to a conventional gasoline jeep engine. However, BO and NOx road emissions
were higher for the TCP jeep than the standard jeep.
j>mokerneter Results .
After each vehicle had reached a hot operating condition the USPHS smoke-
meter was attached to each vehicles' exhaust pipe. The vehicles were then
operated through various driving modes and the per cent light transmittence
was recorded. Table 6 represents the per cent transmittence versus mode
for each vehicle. As indicated by this table, the TCP jeep had a far;-more
opaque exhaust than the standard jeep«
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Summary
The summarizing coionents should be prefaced by the fact that subsequent
testing at ATAC in Detroit revealed an ignition system malfunction that
might have been occurring during this testing. However, results of this
evaluation show:
(l) The TCP jeep produced approximately one-third the CO emissions
of the standard jeep.
(2) The TCP jeep produced 30$ more HC (mass basis) than the standard
jeep.
(3) Nox emissions were higher for the TCP jeep on the road and
slightly lower on the dynamometer as compared to the standard
jeep.
Significant levels of smoke were encountered on all runs with
the TCP Jeep.
8/1968
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NOTE
Cheraical analysis of the exhaust products
Is being prepared by the Chemical
Research and Development Section and will
be available at s later date.
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TABLE 1
SUMMARY OF TESTS
Test
Number
1
2
3
k
5
6
7
8
9
$0
11
12
13
Ik
15
16
IT
18
19
20
21
22
Vehicle
Std
TCP
TCP
TCP
STD
STD
TCP
STD
TCP
TCP
TCP
TCP
TCP
TCP
STD
STD
STD
TCP
STD
TCP
TCP
TCP
Type of
Start
Cold
CoSd
Hot
Cold
Cold
Cold
Hot
Cold
Cold
Hot
Hot
Cold
Hot
Hot
Cold
Hot
Hot
Hot
Fuel
Indolene
Indolene
Indolene
Indolene
Indolene
Indolene
Indolene
Indolena
Indolene
Indolene
Indolene
Indolene
Indolene
Indolene
Indolene
Indolene
Indolene
Indolene
Indolene
Indolene
CITE
Diesel
Sampling*
Method
VDS; SC
VDS ; SC
VDS; SC
VDS; SC
SC
SC
PS
VDS; SC
PS
PS
PS
PS
PS
PS
PS
PS
PS
SC
SM
SM
SM
SM
Type of*
Run
7-mode (D}
7-mode (D)
7-mode (D)
7-mode (D)
7-moda (D)
7-mode (D)
CLA-U (R)
7-mode (D)
CLA-> (R)
CLA-4 (R>
CLA-U (R)
CLA-k (R)
CLA-ii (R)
CLA-U (R)
a,A-i* (R)
CLA-U (R)
CEA-IV (R^
7-mode (D)
7-raode; SS (D)
7-mode; SS fo)
ss (D)
ss (D)
*VDS-Variable Dilution Sampler; S.C.-Scott Cart; PS- Proportional Sampler;
SM-Smokemeter
^(D)-Dynarnoraeter;
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TABLE 2
Jeep Testa
Dynamometer Data
Type of
Cycle
Cold
Hot
7 -mode weighted
Cold
Hot
7-oiode weighted
Test
la
Ib
1
8a
Ob
8
7-isode average
Type of
Cycle
.
7-roode
7-mode
7 -mode
Cold
Hot
weighted
Cold
Hot
weighted
average
Test
_£_
2a
2b
2
4a
4b
*
STD Jeep
HC (IR)
graAaile C6
3.27
1.68
2.23
3.04
2.22
2.50
2.36
TCP Jeep
HC (IR)
Rtn/rolle C£
3.22
2.45
2.72
3.5^
3.18
3-31
3-02
CO
gm Anile
55-34
61.69
59-^5
84.37
61.24
71.12
65.28
CO
Rm/rolle
18.64
18.55
18.58
18.55
17.24
17.82
18.20
C02 KOX
grn/mlle gm/mlle
390.10 2,50
396.90 2.43
39^.51 2.44
414.95
411.87
412.94
403.72 2.44
COg NOX
gjn/rolle gra/mlle
323.42 2.22
308.90 2.09
313.98 2.14
356.35
338.64
344.96
329.47 2.14
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TABLE 3
Jeet) Tests
Concentrations - Dynamometer
Type of
Cycle
h cold
2 hot
weighted
k cold
2 hot
weighted
weighted
weighted
average
Test
JL.
la
Ib
1
8a
8b
8
5
6
STANDARD JEEP
HC (IR)3
PpTO C6
331
221
259
269
2*5
253
273
**
259
C0a
JL
3.81*
3.U6
3.71
U.83
3.95
k.26
U.29
U.19
U.10
11.12
11.33
11.25
10.1U
11.02
10.71
10.72
10.78
10.86
a) California Cycle Composite Values
correction factor " _15...
CO + C02
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TABLE 3 cont.
Jeep Tests
Concentrations • Dynamometer
Type of Test
Cycle ;$
h cold 2a
2 hot 2b
weighted 2
b cold ha
2 hot Ub .
weighted h
TCP Jeep
HC (!R)b
ppm Cfi
222
175
192
ttl
.-, -201
215
C0b
0.18
0.17
0.17
0.21
0.18 .
o.i?
co2b
3. to
3.35
3.37
3.37
3.22
3.27
Average
205
0.18
3.32
b) Composite Values - no correction factor applied-
modified weighting factors used
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.10
TABLE k
CLb-k Road Route
Type of
Jeep
TCP
TCP
AVG
STD
TCP
TCP
TCP
TCP
TCP
AVG
STD -
STD
AVG
Test
9
12
15
7
10
11
13
Ik
16
17
HC (F.I.A.)
ppm HC (C6)
338
JA5_
392
877
313
373
398
36*v
363
503
632
567
COLD STARTS
HC (IR)
ppm C
1815
-2251
2036
35U2
KOT STARTS
1958
1908
2237
2031
2175
2062
21*60
2319
2390
CO
JL
0.26
0.32
0.29
3.10
0.30
. 0.33
0.43
0.32
0.27
0.33
2.85
2.37
2.61
5.26
5.52
5-39
11.7
5.00
5.85
5.56
5.90
5.19
5.50
11.32
10.25
10.79
NOx
ppra
587
J83_
535
505
679
697
592
527
Wto
587
kz6
678
552
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11
TABLE 5
-^ Road Route
Type of
Jeep
TCP
TCP
STD
TCP
;)TC?
TCP
TCP
TCP
STD
STD
Test
9
12
AVG
15
7
10
11
13
AVG
16
*?
AVG
COLD
HC (F.I.A.)
3.99
6.32
5.15
5.29
ROT
3.37
U.61
5.98
5.1?
U- Tl
J^. r7r7
2.71
3.58
3.1*
STARTS (grams /mile)
EC (IR)
3.57
5.35
kM
3.56
STARTS (graras/E
3.50
3.^7
5.61
U.81
U.71
k.kZ
2.17
2.19
' 2.18
CO
10.33
15.31
12.82
63.01
alia)
11. Ik
13.73
21.79
15.31
11.78
1^.75
51-73
1*5.25
U8.U9
C02
328.6
U15.U
372.0
373.7
285.3
382.6
1^2.6
UU3.9
356.9
382.3
322.8
307.5
315.1
! :
J>* \ . .
3.71
3.75
1.63
U.03
11.89
U.12
3.17
^.19
1.27
2.0&
1.67
It/22/68
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12
TABLE 6
Mode
30 nph at Road Load
30 mph at ?l/2$ Grade
30 mph at wide-open throttle
ij-0 mph at road load
kO mph at Jl/2 grade
UO mph at wide-open throttle
Average for 7-mode cycle
(<$> Transmittance*)
STD Jeep TCP Jeep
Indolene
100
100
100
100
100
100
Indolene
100
62
60
98
83
m
CITE
100
72
31
98
83
!>3
Diesel$2
100
7^
-
98
25
»
93
Transraittancei»5 on Ringleman Scale
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13
ILLUSTRATIONS
1. Installation of laminar flow element on Standard jeep.
2. Installation of laminar flow element on TCP jeep.
3. Test Facility
k. Test Facility showing exhaust gas collection method and
hydrocarbon analysis probe.
5. Test Facility
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