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 types:

    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 analysis for carbon monoxide and carbon dioxide with
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 car in 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.

Conclusions

I.  The Marvel-Schebler car demonstrated the attainment of
1972 Federal standards.

2.  The decel-device attached decreases hydrocarbon levels.

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                       Table  I


           Marvel-Schebler  429.CID  LPCJ  Ford


19b8 FTP                   HC ppm     CO %     NO ppm

     With decel             48.1'      .11     404.5
       device


   9 Cycle CVS             HC gpm    CO gpm    NO gpm

     With decel               .91     4.4l-      3-00
       device


1972 FTP

     With decel              1.04     3-77       1.95
       device
     Without decel           1.2"9     3-99       1.94
        device

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