WHAT CAUSES ENGINE AFTERRUN?

A study conducted by Chevron Research Co. into the problem of afterrun (also known as run-on or dieseling) has determined that idle speeds 200 rpm above standard settings contribute to afterrun. Retarded ignition timing and lean mixtures were also factors which increased afterrun. Research octane number (RON) and motor octane number (MON) affected the incidence and severity of afterrun. Afterrun is generally due to autoignition of the air/fuel mixture at high combustion chamber temperatures and pressures. It can occur because of high idle speeds when the engine is not warmed-up.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/2240909
• Corporate Authors:

  Society of Automotive Engineers (SAE)

  400 Commonwealth Drive
  Warrendale, PA  United States  15096
• Publication Date: 1979-9

Media Info

• Pagination: p. 62-63
• Serial:
  • Automotive Engineering
  • Volume: 87
  • Issue Number: 9
  • Publisher: Society of Automotive Engineers (SAE)
  • ISSN: 0098-2571

Subject/Index Terms

• TRT Terms: Combustion; Combustion chambers; Engine idling; Engine performance; Fuel air mixtures; Gasoline; Ignition; Motor fuels; Octane number; Pressure; Temperature; Vehicle power plants
• Uncontrolled Terms: After-run; Air fuel ratio; Timing
• Old TRIS Terms: Automobile engines; Dieseling; Engine afterrun; Idling; Octane rating
• Subject Areas: Highways; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 00325027
• Record Type: Publication
• Source Agency: Engineering Index
• Files: TRIS
• Created Date: Apr 15 1981 12:00AM