RELATIONSHIP BETWEEN LOCAL AIR-FUEL RATIO AND COMBUSTION CHARACTER IN SPARK IGNITION ENGINES

A method for the direct measurement and quantitative analysis of hydrocarbon concentration at any desired point in an engine cylinder allows for the measurement of the air-fuel ratio of the mixture from the hydrocarbon (vaporized fuel) and oxygen concentrations. Either multi-cycle sampling (MCS) or single-cycle sampling (SCS) may be used. The MCS method was used to measure the distribution of air-fuel ratio in a two-stroke engine combustion chamber. Hydrocarbon and air-fuel ratio levels corresponding to crank angle were made in a stratified-charge engine combustion chamber. The SCS method was used to measure the air-fuel ratio at the ignition plug of a four-stroke engine. It was shown that the peak of maximum cylinder pressure is obtained at an air-fuel ratio of approximately 12:1 measured at the ignition plug; its value decreases at any ratio above or below that, suggesting that there is a distribution of air-fuel ratios within the combustion chamber.

  • Supplemental Notes:
    • Presented at the SAE Congress and Exposition, Detroit, 27 February-3 March 1978.
  • Corporate Authors:

    Society of Automotive Engineers (SAE)

    400 Commonwealth Drive
    Warrendale, PA  United States  15096
  • Authors:
    • Ayusawa, T
    • Nemoto, T
    • Koo, Y
    • Jo, S H
  • Publication Date: 1978

Media Info

  • Features: References;
  • Pagination: 18 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00395147
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: SAE 780147, HS-025 303U
  • Files: HSL, USDOT
  • Created Date: Jun 30 1985 12:00AM