71-B
Exhaust Emissions from a Passenger Car Powered by
          Marvel-Schebler LPG Conversion
                  September 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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Vehicle Tested
The exhaust emission characteristics of a 1969 Ford LTD
equipped with a Marvel-Schebler LPG conversion were de-
sired to supplement this agency's information on gaseous
fuel vehicles. The car was equipped with a 429 cubic inch
displacement engine and automatic transmission. In addi-
tion to the equipment necessary for LPG operation the car
had a decel-device which held the throttle partially open
on deceleration.
Tests Conducted
Because the car was only available for three days, tests
were limited to the following t~pes:

1. Standard 1968 Federal test procedure for exhaust
emissions (FTP).
2. A closed, constant volume sampling technique using
9 repeats of the Federal emissions test cycle (CVS).
3. Two closed, constant volume sampling technique using
the LA4-S3 driving schedule as specified for 1972 and
later testing. One test was performed with the.decel-
device, one without.
Closed cycle data were taken using a constant volume sampling
technique. Bag samples were analyzed using non-dispersive
infrared arialysis for carbon monoxide and carbon dioxide.~ith
hydrocarbons measured using a flame ionization detector. The
Whittaker "NOx Box" was used for determination of oxides of
nitrogen in the CVS sample.
Emission Results
Table I shows the test results and indicates the comparison
between the decel-device configuration and no device. As
is shown by the CVS results the carin both configurations
meets or surpasses the 1972 Federal emission standards of
2.9 grams per mile (gpm) hydrocarbon, 37.0 gpm carbon mono-
. xide, 3.0 gpm oxides of nitrogen. With the decel-device
removed hydrocarbons increased about twenty percent.
i
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2.
The decel-device attached decreases hydrocarbon levels.
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Conclusions
1. The Marvel-Schebler car demonstrated the attainment of
1972 Federal standards.

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Table I
Marvel-Schebler ~29 CID LPG Ford.
19b8 FTP
With dece1
device
9 Cycle CVS
With dece1
device
1972 FTP
With dece1
device
Without dece1
device
HC ppm
~e.1
HC gpm
.91
1. 04
1. 29
co %
.11
i CO gpm
.<
~ .
4.41
3.77
3.99
NO ppm
404.5
NO gpm
3.00
1.95
1. 94

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Table I
1963 Ford Galaxie
1970 Federal HC CO NO
Test Procedure GPM GPM GPM
Without device 4.01 53.85 1.62
With Wilford Smog   
Suppressor 6.87 50.16 1. 83

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