LOW TENSION PISTON RINGS AND ROLLER CAM FOLLOWER FOR ENGINE FRICTION REDUCTION-COSTS OF RETOOLING AND FUEL ECONOMY BENEFITS

Automobile manufacturers recognize that two major sources of friction losses in automobile engines are the cam lifter interface and the piston ring interface in each cylinder. In city driving, friction may consume 20 to 30% of the available fuel energy. Perhaps 50% or more of the engine friction in city driving is from the piston rings and 25% is from the conventional valve train containing a flat face follower. Some recent gasoline engine designs have incorporated roller lifters and lower tension rings resulting in energy reduction and improved fuels economy. A methodology for estimating these improvements is presented by the two case studies. For the range of conditions assumed in the study, the composite fuel economy gains for both roller followers and low tension rings ranged from about 3.25% to 5.16%. The low tension rings may have no cost penulty, but they must be designed for adequate sealing, low blowby and good oil consumption. The roller followers and req uired cam improvements vary in cost depending on the valve train design. The cost to the customer will ba about $25 to $35 for a four-cylinder and $45 to $50 for a six-cylinder engine. The details of the methodology and costing are discussed in this report.

• Corporate Authors:

  Chi Associates Incorporated

  Arlington, VA  United States 
• Authors:
  • THUR, G M
  • REILLY, D
  • PATERSON, D J
• Publication Date: 1988-8

Media Info

• Pagination: 24 p.

Subject/Index Terms

• TRT Terms: Blowby; Cost effectiveness; Engine performance; Engines; Friction losses; Fuel conservation; Fuel consumption; Machine valves; Methodology; Pistons (Engines); Rollers; Sealing (Technology); Tension; Vehicle design
• Uncontrolled Terms: Cylinders
• Old TRIS Terms: Engine design; Oil consumption; Sealing; Tension elements; Valve trains
• Subject Areas: Design; Energy; Highways; Vehicles and Equipment; I96: Vehicle Operating Costs;

Filing Info

• Accession Number: 00494276
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: HS-807 332
• Files: HSL, TRIS
• Created Date: May 31 1990 12:00AM