71-15
   Exhaust Emission From Passenger Automobiles'
        Equipped with Doughboy Carburetors
                  December 1970
                 John C. Thomson
Division of Motor Vehicle Research and Development
           Air Pollution Control Office
         ENVIRONMENTAL PROTECTION AGENCY

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Vehicle Tested
Two vehicles, supplied under contract number CPA 22-69-94
to Doughboy Industries, Inc., were tested using the Doughboy
carburetors. One vehicle was a 1970 Chevrolet Impala
equipped with a 350 cubic inch V-8 engine and automatic trans-
mission. This vehicle also had air conditioning and had been
driven 15,000 miles. This vehicle was equipped with two
experimental carburetors and exhaust gas recirculation.
The second vehicle was a 1970 Valiant equipped with a 225
cubic inch six cylinder and automatic transmission. This
vehicle was equipped with an experimental carburetor and
exhaust gas recirculation and had been driven about 22,000
miles.
Tests Conducted
The following types of tests were conducted on these vehicles:
1. Standard 1970 Federal test procedure for exhaust
emissions (FTP).
2. Closed, constant volume sampling technique using
9 repeats of the 7-mode Federal emissions test cycle
( CVS) .
3. Closed, constant volume sampling technique usin~f
the LA4-S3 driving schedule as proposed for 1972 and
later testing (LA4).
The Valiant was tested eight times over 75 miles. The Chevro-
let was tested four times with the carburetors installed and
four times with the stock system in place.
Closed cycle data were taken using a constant volume sampling
technique. Bag samples were analyzed using non-dispersive
infrared analysis for carbon monoxide, flame ionization detec-
tor for hydrocarbons and the Whittaker "NOx Box" for oxides
of nitrogen. During the 1970 tests oxides of nitrogen were
analyzed with non-dispersive infrared analyzers.
Emissions Results
The tests from the Valiant are averaged in Table 1.
vehicle failed to meet any of the emission standards
this year vehicle. Driveability of this vehicle was
ginal during the tests.
This
set for
mar-

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h.
-2-
The tests on the Chevrol~t are averaged in Table 2. The
vehicle failed to meet the standards with either carburetor
system. Unburned hydrocarbons were considerably reduced
when the standard carburetor was installed. The reduction
in carbon dioxide with the standard carburetor would indicate
improvements in fuel economy of the standard over the Doughboy.
Conclusions
There is a considerable amount of work necessary in order to
optimize the Doughboy carburetion for low emissions or to
equal the standard engine.

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  TABLE 1 
 Doughboy Valiant Test Data
  LA4* CVS
Hydrocarbons 4.5 . 4.5
Carbon Monoxide 83 49
Carbon Dioxide 468. 469
Oxides of Nitrogen 3.9 3.7
FTP**
4.6
57
3.0
All results are reported .in grams per mile (gpm).
~
* The 1972 emission standards are HC = 3.4 gpm,
Co= 39 gpm.
** The 1970 emission standards are HC = 2.2 gpm,
CO = 23'gpm.
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  TABLE 2   
 Doughboy Chevrolet Test Data 
  LA4* 'CVS . FTP**
 Carburetors Installed  
Hydrocarbons 6.8  6.0 3.8
Carbon Monoxide  60   60
Carbon Dioxide 650  676 
Oxides of Nitrogen 2.8  4.0 2.8
 Vehicle Returned t.o Stock 
    i  
Hydrocarbons ' 3.8 ; 3.8 2.4
Carbon Monoxide  67  62 47
Carbon Dioxide 547  528 
Oxides of Nitrogen 4.0  4.5 3.8
All results reported in grams per mile (gpm)
*.1972 standards HC = 3.4 gpm, CO = 39 gpm.
** 1970 standards HC = 2.2 gpm, CO = 23 gpm.
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