71-14
Exhaust Emissions From a Vehicle Equipped With the
Roberts Induction Modification Supplied Under Contract CPA 70-51
December 1970
John C. Thomson
Division of Motor Vehicle Research and Development
National Air Pollution Control Administration
""- ENVIRONMENTAL PROTECTION AGENCY
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.Vehicle Tested
A 1970 Plymouth Duster equipped with a 225 cubic inch six
cylinder engine and automatic transmission was modified under
contract C£A 70^-51. ^ The madifioationa designed by Roberta
consisted of changes to the intake manifold, lean main jets
in the carburetor and revised camshaft. The intake modifica-
tion consisted of truncated cone inserts placed in each inlet
port. '
Tests Conducted
The vehicle was tested as received from the contractor and
at two mileage increments. The vehicle was also tested with
the in§@Ft-§ r@mgv§gl from feh§ intake sy§t§m, The fellowing
tests were run: ,
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 using
the LA4-S3 driving schedule as specified for 1972 and
later testing (LA4).
Clos.ed cycle .data were taken using a constant volume sampling
technique. Bag samples from the CVS were analyzed using non-
dispersive infrared analysis for carbon monoxide and the
Whittaker "NOx Box" for determination of oxides of nitrogen,
with hydrocarbons measured using a flame ionization detector.
NDIR was used for continuous NOx measurements in the FTP. tests.
In addition to the standard emission tests, performance .data
was obtained comparing this vehicle with a similar one from
our NAPCA fleet. The tests consisted of wide open throttle
accelerations from 0-60 mphr 20-50 mph and 40-80 mph.
Emission Results
The emission results in table 1 compare the average emissions
as received from the contractor and after removal of the in--
take manifold inserts. The data was taken using the 1972
Federal test procedure. Neither vehicle met the 1972 standards
although hydrocarbons were lower after the device was removed.
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-2-
In Table 2 comparisons between the as received vehicle and
after device removal on the 1970 test procedure shows that
the vehicle meets the standards after the device has been
remeived, although there is a increase in oxides of nitrogen.
Table'3 reports all"emission test results.
* fc
Performance Results
In Table 4 performance results are recorded showing very
similar acceleration times for the 20-50 mph and the 0-60
mph tests but faster acceleration for the standard vehicle
on the 50-80 mph acceleration.
Conclusions
1. The Roberts device caused no significant change in un-
burned hydrocarbons or carbon monoxide. :
2. The Roberts device caused some (27%) reduction in oxides
of nitrogen. . .....-.,>
3. The Roberts device had a small detrimental effect on
performance at high loads.
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TABLE 1
1972 Emission Test Procedure
With
Roberts No
Device Device
Hydrocarbons 3.9 3.4
Carbon Monoxide 43 43
Carbon Dioxide 455 422
Oxides of Nitrogen 2.7 3.7
All values taken by constant volume sampler and
reported in grams per mile. Standards for 1972
•are hydrocarbons 3.4 .gpm and carbon monoxide 39
gpm.
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TABLE 2
1970 Emission Test Procedure
As No
Received Device
Carbon Monoxide 23 19
Oxides of Nitrogen 3.7 4.2
All values taken in accordance with the 1970
Federal procedure and reported in grams per mile.
Standards for 1970 vehicles are hydrocarbons 2.2
gpm and carbon monoxide 23 gpnu NOx measured by
NDIR and reported as NQ2.
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TABLE 3
Mileage Test HC CO CO2 NOx
With
22198
22206
22218
22226
22725
22835
23101
13109
All results
23151
23160
23142
Roberts Device As
9X7
9X7
LA4
LA4
9X7
LA4
LA 4
9X7 :
reported in
Device
9X7
LA4
LA4
FTP
CVS
FTP
CVS
FTP
CVS
FTP
CVS
grams
Receive'd, Test -, Summary
2.85
5.62
2.17
4.48
3.84
3.95
1.92
3.52
3.48
12.47
2.61
4,73
per mile
24.51
44.53
20.96
22.76
42.49
44.43
18.29
30.6
46/4''
51.0
22.91
45 -i 3
452
--.-
459
451
398
522
501
'437.
3.63
3.62
3.91
3.73
2.70
2.69
3.71
4.31
4.06
3.67
4.07;
5.0 •-•;•
Removed,: Test Summary
FTP
1.76
3 . 46
3.39
18.93
37/66
48:86
-*.-
'427
4 IB
4.21
3 . 22
4.32
All results reported in grams:per mile. Vehicle equipped with
lean jets and modified comshaft.
9X7 indicates that the CVS and FTP %ests werevrun concurrently.
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TABLE 4
Performance Test Results
Roberts Vehicle Standard Vehicle
20-50 mph 8.3 sec. 8.4 sec.
0-60 mph 14.6 sec. 14.5 sec.
50-80 mph 17.6 sec. 16.4 sec.
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