This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Variable Compression Pistons
Annotation ability available
Sector:
Language:
English
Abstract
This paper traces the historical development of the BICERI variable compression ratio piston and its use in a number of engines. In early petrol experiments a variable compression piston covering the range from 6.5:1 to 16.5:1 showed significant efficiency improvements on 70 octane petrol. In the diesel engine field, Teledyne Continental increased the power of a V12 direct injection tank engine from 550 hp (30 hp per litre) to 1475hp (80 hp per litre) retaining the original crankcase and structure. At BICERI the output of a supercharged research engine was increased to 40 bar bmep with a peak cylinder pressure of only 165 bar.
Military application lapsed with the preference for gas turbine engines, but the time is now right to explore the capabilities of variable compression within the wider automotive scene. Volkswagen have been working on a variable compression engine and have shown fuel consumption improvements up to 13% together with lower emissions. Mercedes have also been working with Mahle, and in a recent SAE paper showed 9% improvement in fuel consumption together with lower emissions particularly during the start-up phase.
The paper concludes by looking at the long-term potential and verbal presentation will be made of possible future development trends.
Recommended Content
Authors
Topic
Citation
Ashley, C., "Variable Compression Pistons," SAE Technical Paper 901539, 1990, https://doi.org/10.4271/901539.Also In
References
- Gill A.P. “Design Choices for 1990's Low Emissions Diesel Engines” SAE 880350
- Needham J.R. et al “Technology for 1994” SAE 891949
- Thornycroft C.H. “The BICERI Variable Compression Ratio Piston” BICERI Research report No. 59/5 June 1959
- Ladommatos N. et al “Theoretical and Experimental Investigation of a Pressure-Relief Valve for Variable Compression Ratio Pistons” Proc.Instn.Mech.Engrs. 203 99 109
- Wallace W.A. Lux F.B. “A Variable Compression Ratio Engine Development” SAE 762A 1963
- Basiletti J.C. Blackburne E.F. “Recent Developments in Variable Compression Ratio Engines” SAE 660344
- Grundy J.R. et al “AVCR 1360-2 High Specific Output Variable Compression Ratio Diesel Engine” SAE 760051
- Walzer P. et al 1986 15 20
- Adams W.H. et al “Analysis of the Combustion Process of a Spark Ignition Engine with a Variable Compression Ratio” SAE 870610
- Binder K. et al 1986 191 196
- Wirbeleit F.G. et al “Development of Pistons with Variable Compression Height for Increasing Efficiency and Specific Power Output of Combustion Engines” SAE 900229
- Arai T. et al “Variable Compression Ratio Engine for High Power and Low Fuel Consumption - Part 1” JSAE 892100
- 1962
- Griffiths W.J. et al “Pistons for Highly Rated Diesel Engines” T&N Technical Symposium 1990 Wurzburg Paper 18