Evaluation of the Air-Jet
Device^ CTT. , Air Bleed
August 1972
Henry L.
Control Device Evaluation Section
Environmental Protection Agency
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Background
Albano Enterprises, manufacturer of the Air-Jet device,
contacted the Office of Air Programs to request a laboratory
and engineering evaluation of their device. Supplied with
the request was a test report prepared by Olson Laboratories
of Anaheim, California. The test utilized the cold start 1972
Federal emission test procedure and indicated 14% reduction
in hydrocarbon, 20% reduction in carbon monoxide and 31%
reduction in oxides of nitrogen on a 1969 Dodge Dart with the
Air-Jet installed. A confirmatory test program was initiated
by the Test and Evaluation Branch.
Device Description
The Air-Jet device is basically an engine vacuum actuated
valve which allows air to bleed into the engine's PCV system
and subsequently to the intake manifold. The device is installed
in the PCV line between the crankcase and the carburetor.
Technical data supplied by Albano Enterprises states that
"Air-Jet does not function during the idle cycle. At idle
the engine vacuum is at it's maximum, causing the actuator
valve to close. The actuator valve remains closed until the
car is accelerated to 38 to 40 miles per hour. At this point,
the engine vacuum decreases, causing the compression spring to
overcome the vacuum, letting the actuator valve gradually open.
As the speed increases, vacuum continues to decrease, letting
the valve open until it reaches its maximum open position between
60 to 65 miles per hour." It should be noted that while it is
claimed that initial air flow is allowed at 38 mph, technically,
low speed accelerations would subject the valve to vacuums
low enough to allow air flow into the PCV line.
Installation of the system requires cutting the PCV
line and inserting the Air-Jet unit (about 5 minutes).
While no cost data was supplied with the system it is
estimated that installed cost to the consumer would be less
than twenty dollars.
Test Program . v
Baseline and device tests were conducted using a 1970
Valiant equipped with an automatic transmission and 225 CID
six-cylinder engine. A total of four baseline and four device
tests were conducted using the 1975 Federal cold start emission
tests. Details of this test procedure are presented in the
November 10, 1970, and July 2, 1971, Federal Registers.
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Test Results
Data based on the 1975 and 1972 Federal test procedures
are presented in the Appendix of this report. In summary, the
installation of Air-Jet resulted in the following reductions
from baseline:
1972 FTP 1975 FTP
Hydrocarbon CTi 51
Carbon Monoxide 10% 161
Carbon Dioxide 1%* 02
Oxides of Nitrogen 01 2%
Conclusions
The installation of Air-Jet resulted in moderate reductions
of carbon monoxide emissions from the vehicle tested. It did
not appear to have any effect on either hydrocarbon or oxides
of nitrogen emissions beyond changes attributable to normal
test variability.
* increase
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1975 Federal Emission Test Results
(all results in grains per mile)
Baseline
6/22/72
6/23/72
7/05/72
7/06/72
Average
Air-Jet
6/24/72
6/29/72
6/30/72
7/03/72
Average
Percent Reduction
HC
1.8
2.1
1.8
1.5
1.8
1.6
1.8
1.6
1.7
1.7
61
CO
1870
17.4
16.1
15.6
16.8
12.7
16.2
14.5
14.4
14.5
16%
C09
408.7
417.6
437.4
408.9
418.2
415.0
421.3
409.2
432.5
419.5
0%
NOx
6.4
6.4
6.3
5.8
6.2
6.0
6.4
5.6
6.5
6.1
2%
Baseline
6/22/72
6/23/72
7/05/72
7/06/72
1972 Federal Emission Test Results
(all results in grams per mile)
Average
Air-Jet
6/24/72
6/29/72
6/30/72
7/03/72
Average
Percent Reduction
HC
2.
2.
2.
1.
2.
1.
2.
1.
2.
2.
0%
2
1
0
8
0
9
2
9
0
0
CO
32.
31.
29.
28.
30.
24.
30.
j 27.
27.
27.
10%
5
6
5
6
6
4
4
5
5
5
CO-
413
423
437
409
421
422
425
411
440
425
1%*
NOx
.0
.8
.4
.8
.0
.3
.6
.3
.6
.0
6
6
5
5
5
5
6
5
6
5
0
.0
.1
.8
.5
.9
.8
.2
.2
.4
.9
%
^increase
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