THE EFFECTS OF ENGINE VARIABLES AND EXHAUST GASE RECIRCULATION ON EMISSIONS, FUEL ECONOMY, AND KNOCK -- PART III

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 changeing 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. Some possible explanations for these differences are presented. /GMRL/

• Corporate Authors:

  Society of Automotive Engineers (SAE)

  400 Commonwealth Drive
  Warrendale, PA  United States  15096
• Authors:
  • Morgan, C R
  • Kirklin, P W
• Publication Date: 1977

Media Info

• Pagination: 32 p.

Subject/Index Terms

• TRT Terms: Compression; Engines; Exhaust gases; Fuel air mixtures; Fuel consumption; Octane number; Spark ignition engines; Variables
• Uncontrolled Terms: Air fuel ratio
• Old TRIS Terms: Compression ratio; Octane rating; Recirculation
• Subject Areas: Energy; Highways; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00158394
• Record Type: Publication
• Report/Paper Numbers: SAE 770192
• Files: TRIS
• Created Date: Dec 8 1977 12:00AM