In this study, a laboratory test procedure to mimic the life cycle of the small air-cooled engines in field operation is developed. A characterization of exhaust emissions over the life cycle of the engines is achieved with special focus given to the hydrocarbon emissions. Both Briggs and Stratton four-stroke (four-cycle) overhead-valve and side-valve engines with a nominal power output of 3.7 kW (5 hp) are used in this study. Different levels of emissions are observed for each type of engine configuration, and it is noted that the hydrocarbon emissions changed more than CO or NOx emissions. These data support the idea that combustion chamber deposits (CCD) are a significant cause of deteriorating emissions. Chemical analysis techniques are applied to the CCD, and it is found that the deposits consist primarily of polynuclear aromatic compounds and unsaturated hydrocarbons.

Issue Section:
Internal Combustion Engines
Keywords:
internal combustion engines, emission, combustion, condensation, organic compounds, chemical variables measurement, thermal variables measurement
Topics:
Emissions, Engines, Cycles, Combustion chambers, Exhaust systems, Nitrogen oxides
1.
Gabele, P., 1997, “Emissions From 4-Cycle Walk-Behind-Mover Engines: Test Cycle Effects,” SAE Paper No. 972793.
2.
Haidar, H. A., and Heywood, J. B., 1997, “Combustion Chamber Deposits Effects on Hydrocarbon Emissions From a Spark-Ignition Engine,” SAE Paper No. 972887.
3.
Valdatoros, T. H., Wong, V. W., and Heywood, J. B., 1991, “Fuel Additive Effects on Deposit Build-up and Engine Operating Characteristics,” Symposium on Fuel Composition/Deposit Tendencies, American Chemical Society, 36(1).
4.
Wagner, R. W., 1993, “The Effects of Fuel Composition and Deposit Control Additives on Combustion Chamber Deposits,” Proceedings of the CRC Workshop on Combustion Chamber Deposits, Nov.
5.
Bower, S. L., Litzinger, L. A., and Frottier, V., 1993, “The Effect of Fuel Composition and Engine Deposits on Emissions from a Spark Ignition Engine,” SAE Paper No. 932707.
6.
SAE J1088 Recommended Practice, 1993, test procedure for the measurement of gaseous exhaust emissions from small utility engines.
7.
Federal Register, 1995, “Control of Air Pollution; Emission Standards for New Non-road Spark-Ignited Engines at or Below 19 Kilowatts,” Fed. Reg. 40 CFR Parts 9 and 90, Final Rule, 60(127), July 3.
8.
Siegl, W. O., and Zinbo, M., 1985, “On The Chemical Composition and Origin of Engine Deposits” Chemistry of Engine Deposits, Plenum Press, New York.
9.
Harpster, M. O., Jr., Matas, S. E., Fry, J. H., and Litzinger, T. A., 1995, “An Experimental Study of Fuel Composition and Combustion Chamber Deposit Effects on Emissions From a Spark Ignition Engine,” SAE Paper No. 950740.
10.
Reisel
,
J. R.
,
Kellner
,
T. A.
, and
Neusen
,
K. F.
,
2000
, “
Speciated Hydrocarbon Emissions in Small Utility Engines
,”
J. Air Waste Manag Assoc.
,
50
, pp.
522
–
528
.
11.
Kalghatgi, G., 1990, “Deposits in Gasoline Engines—A Literature Review,” SAE Paper No. 902105.
12.
Daly, D. T., Bannon, S., Fog, D., and Harold, S., 1994, “Mechanisms of Combustion Chamber Deposit Formation,” SAE Paper No. 941889.
13.
Lepperhoff, G., and Houben, M., 1993, “Mechanisms of Deposit Formation in Internal Combustion Engines and Heat Exchangers,” SAE Paper No. 931032.
14.
Solum
,
M.
,
Pugmire
,
R. J.
, and
Grant
,
D. M.
,
1989
, “
13C Solid State NMR of Argonne Premium Coals
,”
Energy Fuels
,
3
, pp.
187
–
193
.
15.
Edwards, J., and Choate, P., 1993, “Average Molecular Structure of Gasoline Engine Combustion Chamber Deposits Obtained by Solid-State 13C, 31P, and 1H Nuclear Magnetic Resonance Spectroscopy,” SAE Paper No. 932811.
16.
Kim, P., Cheng, S., and Majorski, S., 1991, “Engine Combustion Chamber Deposits: Fuel Effects and Mechanisms of Formation,” SAE Paper No. 912379.
17.
Adams, K. M., and Baker, R. E., 1985 “Effects of Combustion Chamber Deposit Location and Composition,” Chemistry of Engine Deposits, Plenum Press, New York.
Copyright © 2003
 by ASME
You do not currently have access to this content.