71-10
Exhaust Emissions from 10 GSA Rebels and 10 GSA Falcons
Equipped with LPG Conversion Kits
October 1970
Henry L. Gompf
Division of Motor Vehicle Research and Development
National Air Pollution Control Administration
Department of Health, Education, and Welfare
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Vehicles Tested
The exhaust emission characteristics of ten ialcons and ten
Rebels were measured before and after installation of
liquefied gas (LPG) kits. The gaseous systems used were
the Impco, Model J regulator and carburetor, ipstalled by
PetrolaneIncorporated. The cost of this installation is
approximately $300. In addition to the gaseous fuel kit,
the distributor vacuum advance was disconnected. The cars
were tuned to TDC ignition timing and 600 rpm in drive.
The 1970 Falcons have a 250 CID engine with automatic trans-
mission and original manufacturer's specifications of six
degrees BTDC and 550 rpm in drive. The 1970 Rebels have a
232 CID engine with automotic transmission and original
manufacturer's specifications of three degrees BTDC and
550 rpm in drive. The Falcons were further modified by the
installation of hardened valve seats.
Two vehicles were evaluated more extensively than the other
18 and will be discussed separately in this report.
Test$ Conducted
. .-
Base.line- Te$t$.: --
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I
All vehicles were tested prior to installation of LPG
conversion kits using the constant volume sampling
te~hnique with the LA 4-83 driving schedule as specified
for 1972 and later testing.
LPG Conversion Tests:
The following tests were performed on the converted
vehicles. All of the cars were not available to receive
all of the tests.
1.
Standard 1970 Federal test procedure for exhaust
emissions (FTP).
2.
Closed, constant volume sampling technique using
nine repeats of the Federal emission 7-mode test.
cycle (9 CV8).
3.
Closed, constant volume sampling technique using
the LA 4-83 driving schedule as specified for
1972 and later testing. .
Closed cycle data \vere taken using .a constant volume sampling
technique. Bag sam9les were analyzed using non-dispersive
infrared analysis for carbon monoxide with hydrocarbons
measured using a flame ionization ~etector. The Whittaker
"NOx Box", an electro-chemical device, was used for deter-
mination of oxides of nitrogen in the CV8 sample.
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In addition to the standard emission tests, performance
data was obtained for some of the vehicles. The accelera--
tion tests consisted of wide open throttle acceleration
(WOT) from 0-60 mph, 20-50 mph, 50-80 mph.
Emission Results
Rebels:
Table I shows the test results for nine Rebels tested.
The average baseline values (gasoline operation) for
these cars obtained using the 1972 Federal emissions
test procedure are 2.67 grams per mile (gpm) hydro-
carbons, 22.13 gpm carbon monoxide, and 6.85 gpm oxides
of nitrogen. The 1973 Federal emissions standards of
3.4 gpm hydrocarbons, 39 gpm carbon monoxide" and 3.0,
gpm oxides of nitrogen were not met by any vehicle while
seven of the nine gasoline powered vehicles reported met
the 1972 Federal emission standards (no NOx requirement).
The range of hydrocarbon values was 4.23 gpm to 1. 60 qpm,
carbon monoxide from 55.38 gpm to 9.09 gpm, oxides of
nitrogen from 8.28 gpm to 3.59 gpm. After installation
of the LPG conversion kits the average 1972 Federal
emissions test results were lowered to 0.51 gpm hydro--
carbons, 3.89 gpm carbon monoxide and 3.13 gpm oxides
of nitrogen. Five vehicles met the 1973 Federal emissions
standards. Three met the 1975 standards of 0.46 gpm
hydrocarbon, 4.7 gpm carbon monoxide, and 3.0 gpm oxides
of nitrogen (as N02). None of the Rebels could meet
1976 Federal emissions standards because of the very
low NOx requirement. The range of results was hydro-
carbons from 1.28 gpm to 0.14 gpm, carbon monoxide from
27.50 gpm to 1. 24 gpm, and oxides of nitrogen from 3.93
gpm to 2.39 gpm. The 9 CVS procedure was used on only
four of the Rebels giving average values of 0.98 gpm
hydrocarbons, 3.37 gpm carbon monoxide, and 3.48 gpm
oxides of nitrogen. In general this procedure appears
to result in slightly higher emission values for thesŤ:
cars. The average values of emissions obtained using
the 1970 FTP were 0.91 gpm hydrocarbons and 2.42 gpm
carbon monoxide. The range of results was 1.50 gpm to
0.54 gpm hydrocarbon and 3.26 gpm to 1.09 gpm carbon
monoxide. The 1970-1971 Federal emission standards are
2.2 gpm hydrocarbon and 23 gpm carbon monoxide.
.
~
Comparing the baseline results to the gaseous fuel
results (1972 FTP), reductions of 81 percent in hydro-
carbons, 82 percent in carbon monoxide and 54 percent
in oxides of nitrogen were realized with the LPG
conversion for the nine Rebels reported.
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Falcons:
Table II shows the test results for nine Falcons tested.
The average baseline values (gasoline operation) for
these cars obtained using the 1972 FTP are 3.70 gpm
hydrocarbons, 15.99 gpm carbon monoxide, and 9.43 gpm
oxides of nitrogen. None of the gasoline powered
Falcons met ttie 1973 Federal emissions standards and
three met the 1972 standards. The range of values was
4.34 gpm to 2.81 gpm hydrocarbons, 24.62 gpm to 11.01
gpm carbon monoxide and 12.18 gpm to 7.85 gpm oxides of
nitrogen. After installation of the LPG conversion kit
the average 1972 FTP results were 0.69 gpm hydrocarbons,
1.76 gpm carbon monoxide, 2.59 gpm oxides of nitrogen.
Seven vehicles met the 1973 Federal emission standards;
none met the 1975 standards. The range of emissions
values was 1.15 gpm to 0.20 gpm hydrocarbons, 2.42 gpm
to 1.33 gpm carbon monoxide and 3.89 gpm to 1.26 gpm
oxides of nitrogen. The 9 CVS procedure was used on
eight of the vehicles giving average values of 0.69 gpm
hydrocarbon, 1.74 gpm carbon monoxide and 3.21 gpm
oxides of nitrogen. Again this procedure tends to give
somewhat higher .emission values than the 1972 FTP. The
range of values for the 9 CVS was 1.03 gpm to 0.50 gpm
hydrocarbons, 3.47 gpm to 1.19 gpm carbon monoxide and
4.92 gpm to 1.63 gpm oxides of nitrogen. The average
values of emissions obtained using the 1970 FTP were
0.57 gpm hydrocarbons and 1.88 gpm carbon monoxide. The
range of values obtained for the 1970 FTP was 0.90 gpm to
0.33 gpm hydrocarbons and 2.61 gpm to 0.87 gpm carbon.
monoxide. .
Comparing the baseline results to the gaseous fuel
results (1972 FTP) reductions of 81 percent in hydro-
carbons, 89 percent in carbon monoxide, and 73 percent
in oxides of nitrogen were realized with the LPG
conversion for the nine Falcons reported.
Performance Tests
.Acceleration tests were conducted on four Rebels and four
Falcons after installation of LPG conversion kits. The
tests were run with a passenger load of 350 pounds. Table
III shows the actual test results for three accelerations
20-50 mph, 0-60 mph, and 50-80 mph. The Rebels averaged
an elapsed time of 11.4 seconds for the 20-50 mph accelera-
tion, 20.0 seconds for the 0-60 mph and 31.0 seconds for
the 50-80 acceleration. The range of times were respectively
12.0 to 10.8 seconds, 25.8 to 17.2 seconds, and 52.0 to 21.2
seconds. .
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A 1969, gasoline-powered, Ambassador (a heavier vehicle
than the Rebel) with a 232 CID engine was tested for
comparative purposes. The car had accumulated 31,000
miles and had an ignition problem causing it to break-
down during the 50-80 mph acceleration. The Ambassador
averaged 9.6 seconds for the 20-50 mph acceleratiop and
17.9 seconds for the 0-60 mph. Thus even in poor
mechanical condition it displ~yed better acceleration
performance than the 1970 low-mileage Rebels.
The Falcons averaged an elapsed time of 11.4 seconds for
the 20-50 mph acceleration, 20.1 seconds for the 0~60 mph
acceleration and 31. 6 seconds for the 50-80 mph acceieration.
The range of times ~vere respectively: 15.2 to 8.0 seconds,
25.2 to 15.5 seconds, 43.6 to 21.8 seconds. Although no
tests were run on the gasoline equipped vehicles it was
obvious to test personnel that performance had been
appreciably sacrificed. The LPG equipped cars had serious
tip-in problems and demonstrated stretchiness on accelera-tion.
One Rebel was tested with the ignition timing advanced to 3°
before TDC as well as at the gaseous fuel specification of
TDC. The following table indicates the comparison of these
two configurations:
TDC 3° BTDC
Acceleration Seconds Seconds
20-50 mph 12.0 8.9
0-60 mph 19.0 17.0
50-80 mph 24.5 22.9
The percentage improvement by advancing the timing in this
way was 26 percent for the 20-50 mph acceleration, 11 percent
for the 0-60 mph acceleration, and 7 percent for the 50-80
mph acceleration.
Extended Vehicle Evaluation
One Rebel and one Falcon were placed in the Test and Evaluation
Branch's vehicle fleet. Mileage accumulation, periodic
emission testing, fuel consumption, comparative performance
testing, and general observations were made on these vehicles.
Table IV indicates the emission test results obtained with
these vehicles. The average Rebel emissions utilizing the
1972 FTP were 0.38 gpm hydrocarbons, 1.86 gpm carbon monoxide,
and 2.47 gpm oxides of nitrogen. This represents reductions
over baseline of 86 percent in hydrocarbons, 84 percent in
carbon monoxide, and 70 percent in oxides of nitrogen. The
average Falcon 1972 FTP emissions were 0.85 gpm hydrocarbons,
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1.61 gpm carbon monoxide, and 3.05 gpm oxides of nitrogen..
This represents reductions over baseline of 69 percent in
hydrocarbons, 92 percent in carbon monoxide, and 61 percent
in oxides of nitrogen.
The Rebel was driven about 700 miles under ordinary driving
conditions. As Table I'indicates no appreciable change in
the emissions levels was reported.
Because of the performance problem apparent with the
conversion to LPG it was desired to measure the effect of
advancing the timing to 6° before TDC on the Falcon.. This
helped the overall performance of the car, but as Table I
indicates resulted in an increase in all three pollutants.
Hydrocarbons increased by 22 percent over the optimized
LPG configuration; carbon monoxide increased 13 percent;
and as expected oxides of nitrogen rose 35 percent above
the retarded level.
Fuel consumption data was collected during the mileage
accumulation phase of the evaluation of the vehicles. As
indicated the Rebel consumed 63.4 gallons in 559 miles for
an average fuel consumption rate of 8~8 miles per gallon.
The Falcon used 12.4 gallons when"driven 139.0 miles (with
timing advanced to 6° before TDC) for-an average consumption
rate of 11.2 miles per gallon.
One technical problem which occurred during winter driving
deserves comment. On days below 32° F the small regulators
installed with the LPG conversion \vould freeze. This
resulted in the necessity of thawing with hot water before
the car could be driven away. This problem was remedied by
the installation of large capacity regulators.
Conclusions
1.
The LPG conversion adopted on these. cars resulted in
overall average emission levels according to the 1972
FTP of 0.60 grams per mile hydrocarbons, 2.83 grams
per mile carbon monoxide, and 2.86 grams per mile oxides
of nitrogen. Twelve vehicles tested surpassed the 1973
Federal standards, but only three met the proposed 1975
Federal standards (0.46 gpm hydrocarbons, 4.7 gpm carbon
monoxide, and 3.0 gpm oxides of nitrogen). None of the
20 vehicles tested could meet the stringent NOx standard
proposed for 1976 model year vehicles. With proper
adjustments the hydrocarbon levels could be brought below
the 0.47 gpm level. The control of carbon monoxide is
well below any standards yet established. It does appear,
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however, that a specific control for the oxides of
nitrogen is necessary to bring the cars consistently
to the 1976 level.
One other consideration, not previously mentioned, is
that the vehicles running on LPG do generate a distinctive
odor. This seems objectionable and should be curbed.
2.
A penalty caused by the installation of the LPG
conversion kit is performance. The driveability of the
vehicles \vas appreciably damaged. Some of the vehiclt2!s
showed such sluggishness that high speed entrance to
expressways could prove to be hazardous. To some
extent this problem was lessened by advancing the timing
with a resulting yet tolerable increase in emissions.
3.
While data on fuel consumption of the gasoline powered
vehicles was not available, it can be safely assumed
that an average of 8.8 mpg and 1'1.2 mpg (with advanced
timing) is well below the mileage attainable by these
light weight small displacement vehicles when running
on gasoline.
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TABLE I
Emissions Results - Rebels
Baseline LPG Equipped
Car
I Number 1972 FTP 1972 FTP 1970 FTP 9, CVS
II G 11 grams/mile grams/mile grams/mile grams/mile
I HC CO NOx* HC CO NOx* HC CO NOx*' HC CO NOx*
I 44044 4.23 55.38 8.04 .14 2.24 3.89 ' .
,
.16 2.49 3.82
. ~ 54378 2.67 20.70 7.27 .40 1. 52 2.39
:
\ .33 1.24 2.67
1
54368 2.24 13.78 6.04 . 56 1,1. 59 2.88 .76 1. 52 2.47 ..77, ~ 1.58 3.20 .,.....'t"Y~.
1 ~
.52 1. 67 2.47 .77 1.09 3.20 .83 1.09' 2.82
J 54369 3.62 28.98 7.59 1.28 27.56 3.88 1. 50 3.26 6.12 1. 79 9.83 4.08
I
1.14 11. 59 3.66 1. 28 3.91 6.47 1.42 3.87 4.66
54380 1. 60 19.52 3.59 .38 '1.51 2.96
.36 1. 86 2.74
54373 2.34 9.09 8.28 .41 1.49 3.71
.43 1. 70 3.34
54360 1. 89 9.95 6.19 .35 2.81 3.92
.39 2.14 3.11
54364 2.18 18.48 6.85 .47 2.38 2.27 .54 3.04 2.28 .65 4.67 2.30
.32 1. 95 2.84 .57 1. 95 2.25 .55 2.50 2.73
. 54370 3.28 23.31 7.82 .71 2.34 2.96 .81 3.26 5.14 .90 1.55 3.94
I .74 1. 94 3.30 1.12 1.30 5.83 .89 1.84 4.08
i
1
I
I Average 2.67 22.13 6.85 .51 3.89 3.13 .91 2.42 4.22 .98 3.37 3.48
I
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I
i * presented as N02 not corrected for humidity
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'1. ~LE II
Emissions Results - Falcons
Baseline LPG Equipped
i J Car
i Number 1972 FTP 1972 FTP 1970 FTP 9CVS °
G 11 grams/mile grams/mile grams/mile grams/mile
HC CO NOx* HC CO NOx* ° HC CO NOx* HC CO NOx*
54356 3.17 11.01 9.73 .97 1. 63 2.79 .65 2.61 1.92 .81 1. 59 2.82
.85 1. 46 2.94 .64 2.39 1. 52 .78 1.59 3.04 {
46982 4.19 13.07 9.96 .54 1.67 2.76 .47 1. 30 3.37 .60 2.11 4.19
.56 2.42 2.67 .46 1. 09 3.37 .59 2.43 3..80
49738 3.66 13.05 9.20 .47 1. 33 3.89 .39 2.39 3.89 .51 1.19 4.92
-- :
.52 1. 37 3.:'/1 .43 2.61 - 3.84 .53 1. 29 4.92
54352 2.81 16.82 8.02 .48 1.74 2.99 .39 1. 52 3.69 .50 1. 24 4.08
.50 1.58 3.48 .33 1. 52 3.49 .47 1. 57 4.15
1.14 1.82 1.26 .86 1. 52 1.32 1.01 1.69 1.67
49741 4.21 24.62 12.17 1.15 1. 89 1. 46 .90 2.61 1.21 1.03 1.85 1.81
i 1.11 2.04 1. 38 ---- ----
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.55 1.94 2.56 .54 .87 2.38 .65 1.80 3.27
- 46983 3.33 22.97 8.06 .70 1.46 2.68 0.50 .87 2.85 .63 1. 39 3.51
; .64 2.28 2.39
i i
j
i 46988 4.34 13.67 10.49 .26 2.61 2.57
! .20 1. 62 3.77
j
j 46985 3.56 15.77 9.31 1. 06 1. 53 1. 81 .82 1.96 2.16 .95 ° 1. 43 2.90
I .94 1. 54 2.02 .90 1. 96 2.19 .93 1. 51 2.52
49734 4.04 12.91 7.85 .56 1. 62 1. 89 .45 2.39 1.33 .56 3.47 1. 62
i .61 1. 58 1. 70 A' '''' "In "'J"\ c:n , e;.e;. 1.92
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Average 3.70 15.99 9.43 . 69 1. 76 2.59 . 57 1.88 2.45 .69 1.74 3.20
1 !
1
I- 1 * presented as NO.7, not corrected for humidity
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TABLE III
Performance Results - Rebels and Falcons
Rebels
Car Number Accelerations
G 11 20-50 mph 0-60 mph 50-80 mph
54368 12.0 seconds 19.0 seconds 24.5 seconds
54369 11.5 seconds 23.4 seconds 52.0 seconds
54364 11.1 seco'nds 19.7 seconds 26.0 seconds
54370 10.8 seconds 17.7 seconds 21.5 seconds
Falcons
Car Number Accelerations
G 11 20-50 mph 0- 60 mph 50-80 mph
54356 10.9 seconds 18.5 seconds 22.7 seconds
46982 11.5 seconds 21.1 seconds 28.4 seconds
49741 15.1 seconds 25.2 seconds 43.6 seconds
46983 8.2 seconds 15.5 seconds -------------
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TA- ~ IV
Emission Results - Extended Evaluation
(all results as grams per mile)
Rebel G 11 - 54372
Gasoline Baseline LPG Conversion Results
1972 FTP 1972 FTP 9 CVS 1970 FTP
HC CO NOx* Odometer HC CO NOx* HC CO NOx* HC CO NOx*
2.67 11. 49 8.11 3570 mi. .33 2.29 2.10 .49 2.64 2.44 .47 2.33
.35 1.66 2.21 .59 2.95 1. 81 .46 1. 23 2.56
.
. ,
4070 mi. .37 1.08 2.03 .54 1. 39 3.15 .60 1.52 3.51
.34 1.10 2.07 .54 1. 54 3.45
4200 mi. .30 2.54 2.54 ----
.48 2.26 3.11
.39 1. 41 2.85
.51 2.55 2.82
Average .38 1. 86 2.47 .54 2.13 2.71 " .51 1. 69 3.03..
Falcon G 11 - 46989.
,
11 Gasoline Baseline LPG Conversion Results
1972 FTP 1972 FTP 9 CVS 1970 FTP
I HC CO NOx* Odometer HC CO NOx* HC CO NOx* HC CO NOx*
I
1 2.74 7.80 2500 mi. .94 1. 01 1. 79 . 4.13 1.04 1.07
20.69 1. 98 3.52 4.26
.75 1. 24 2.58 .86 1. 47 3.29 .84 1.24 5.04
Average .85 1. 61 3.05 .94 1. 63 3.71 .94 1.16 4.66
NOTE:
2800 mi. 1.07 1. 83 4.74
1.22 1. 72 4.54
~88 1. 67 4.83
.98 2.12 4.77
Average 1.04 1. 84 4.72
* presented as N02, .corrected for humidity
NOTE: timing advanced 6° BTDC
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TABLE V
GSA LPG Vehicles
Fuel Consumption
t
Rebel G 11 - 54372
Mileage Driven
Fuel Consumed
MPG
153.0 mi
17.0 gal
15.0 gal
9.0 mpg
137.0 mi
9.1 mpg
154.0 mi
18.0 gal
13.4 gal
8.6 mpg
8. 6 mpg
115.0 mi
559.. 0 mi
63.4 gal
Average fuel consumption
8.8 miles per gallon
Falcon G 11 - 46989
Mileage Driven
Fuel Consumed
MPG
139.0 mi
12.4 gal
11.2 mpg
Average fuel consumption
11.2 miles per gallon
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