This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
THE EFFECTS OF ENGINE VARIABLES AND EXHAUST GAS RECIRCULATION ON EMISSIONS, FUEL ECONOMY, AND KNOCK - PART III
Annotation ability available
Sector:
Language:
English
Abstract
Steady-state engine mapping data were obtained from a 400 CID V-8 spark-ignition engine at compression ratios of 8.0 and 9.3:1 to determine the effect of compression ratio on fuel consumption and octane number requirement at various exhaust emission levels. The results indicate that increasing compression ratio from 8.0 to 9.3 decreases BSFC without changing BSNOx emissions, but increases BSHC emissions. Additionally, when BSHC emissions are maintained at the constant levels considered in this study, the minimum BSFC decreases with increasing compression ratio and is obtained at A/F ratios of 16 to 18:1. Since this trend of decreased fuel consumption with increasing compression ratio at fixed HC and NOx emission levels is the opposite of that indicated by earlier studies using a single-cylinder RDH engine, some possible explanations for these differences are presented. In actual vehicle operation, octane requirements would generally increase with increasing compression ratio. Other studies, however, have shown that the energy savings due to improvement in engine efficiency with increased compression ratio may be more than offset by refinery losses incurred in producing higher octane fuels.
Authors
Topic
Citation
Morgan, C. and Kirklin, P., "THE EFFECTS OF ENGINE VARIABLES AND EXHAUST GAS RECIRCULATION ON EMISSIONS, FUEL ECONOMY, AND KNOCK - PART III," SAE Technical Paper 770192, 1977, https://doi.org/10.4271/770192.Also In
References
- Morgan C. R. Hetrick S. S. “Trade-Offs Between Engine Emission Control Variables, Fuel Economy, and Octane” Paper 750415 SAE February 1975
- Schweikert J. F. Gumbleton J. J. “Emissions Control with Lean Mixtures” Paper 760226 SAE February 1976
- Morgan C. R. Hetrick S. S. “The Effects of Engine Variables and Exhaust Gas Recirculation on Emissions, Fuel Economy, and Knock - Part II” Paper 760198 SAE February 1976
- Patterson D. J. Henien N. A. “Emissions from Combustion Engines and Their Control” Ann Arbor Science Publishers, Inc. Ann Arbor, Michigan 1972
- Felt A. E. Krause S. R. “Effects of Compression Ratio Changes on Exhaust Emissions” Paper 710831 SAE October 1971
- Scheffler C. E. “Combustion Chamber Surface Area, A Key to Exhaust Hydrocarbons” Paper 660111 SAE January 1966
- Gumbleton J. J. Niepoth G. W. Currie J. H. “Effect of Energy and Emission Constraints on Compression Ratio” Paper 760826 SAE October 1976
- Spindt R. S. “Air-Fuel Ratios from Exhaust Gas Analysis” Paper 650507 SAE Automotive and Engineering Congress Detroit February 1974
- “Test Procedure for Measurement of Small Utility Engine Exhaust Emissions” Test Procedure Subcommittee of SAE Engine Committee