AN INVESTIGATION OF THE FACTORS REDUCING THE PUMPING LOSS OF A GASOLINE ENGINE

The gasoline engine's load is controlled by varying the amount of intake air-fuel mixture. Throttling, which is used for this purpose, gives rise to pumping loss, and this is one of the factors that prevent improvement in the fuel economy of gasoline engines. This pumping loss is particularly large during partial load condition. With a view to improving fuel economy, an analysis of the factors reducing pumping loss, as well as their respective degree of influence, was done using both experiments and calculations. From this analysis, the degrees of reducing pumping loss by means of an increase in the EGR rate, a reduction in the number of working cylinders and a shortening of the intake stroke length were clarified. Furthermore, it was also found that it is possible to estimate the reduction effect mathematically. This paper also discusses the secondary effects on combustion characteristics and other losses which accompany the reduction in pumping loss as well as their influence on fuel economy.

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  • Corporate Authors:

    Society of Automotive Engineers of Japan

    10-2 Goban-cho, Chiyoda-ku
    Tokyo,   Japan 
  • Authors:
    • NAKAJIMA, Y
    • Nagumo, S
    • HARA, S
  • Publication Date: 1983-11

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Filing Info

  • Accession Number: 00389059
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: HS-036 597
  • Files: HSL, USDOT
  • Created Date: Sep 28 1984 12:00AM