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Research Engine for Evaluating the Effects of Variable Compression Ratio (VCR) and/or Variable Valve Timing (VVT)
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English
Abstract
The design of a single-cylinder Otto-cycle test engine is described in which the timing of both intake- and exhaust valves, as well as the volume of the compression space can be independently varied within wide limits during operation.
The proposed engine is of all-welded construction and uses stock engine components where practical to minimize production cost. Valve opening and closing is by positive cam action (desmodromic) with a differential gearset providing the phase shift between these functions.
The upper portion of the engine, comprising the cylinder head and block, is connected to the crankcase through a hinge parallel with the crankshaft axis and a pre-loaded hydraulic actuator. This arrangement allows variations of the minimum distance between the top of the piston and the cylinder head without affecting the valve timing significantly.
An oscillating counterweight, in line with, and 180 deg. out-of-phase with the piston, eliminates vibration due to first and second order inertia forces, thus allowing the 0.72 liter displacement engine to be run at high speeds without requiring a heavy test bed foundation.
A simplified form of the valve mechanism, offering a reduced range of adjustment, as well as the “hinged-block” construction which enables VCR, are readily incorporated in production-type engines.
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Authors
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Citation
Larsen, G., "Research Engine for Evaluating the Effects of Variable Compression Ratio (VCR) and/or Variable Valve Timing (VVT)," SAE Technical Paper 910053, 1991, https://doi.org/10.4271/910053.Also In
References
- Luria, D. Taitel, Y. Stotter, A. 1982 “The Otto-Atkinson Engine - A New Concept in Automotive Economy” SAE Paper 820352
- Luria, D. July 5 1977
- Luria, D. April 18 1978
- Tuttle, J.H. 1980 “Controlling Engine Load by Means of Late Intake-Valve Closing” SAE Paper 800794
- Saunders, R.J. Abdul-Wahab, E.A. 1989 “Variable Valve Closure Timing for Load Control and the Otto Atkinson Cycle Engine” SAE Paper 890677
- Pouliot, H.N. Delameter, W.R. Robinson, C. W. 1977 “A Variable-Displacement Spark-Ignition Engine” SAE Paper 770114
- Bouchard, G.R. November 28 1950
- Obert, E.F. Internal Combustion Engines and Air Pollution New York Intext Educational Publishers 1973 304 334
- Wallace, W.A. Lux, F.B. 1963 “A Variable Compression Ratio Engine Development” SAE Paper 762A
- Adams, W.H. Hinrichs, H.G. Pischinger, F.F. Adamis, P. Schumacher, V. Walzer, P. 1987 “Analysis of the Combustion Process of a Spark Ignition Engine with a Variable Compression Ratio” SAE Paper 870610
- Harne, V. Marathe, S.R. 1989 “Variable Compression Ratio Two-Stroke Engine” SAE Paper 891750
- Agnew, B. Palmer, D.C. Tam, I.C.K. 1986 “Examination of the use of variable compression ratio piston in a spark ignition engine Practical limits of efficiency of engines London Mechanical Engineering Publications for The Institution of Mechanical Engineers 77 84
- Wirbeleit, F.G. Binder, K. Gwinner, D. 1990 “Development of Pistons with Variable Compression Height for Increasing Efficiency and Specific Power Output of Combustion Engines” SAE Paper 900229
- Setright, L.J.K. 1975 Some Unusual Engines London Mechanical Engineering Publications for The Institution of Mechanical Engineers 85 88
- Edwards, J.V. 1983 “Ceramics and the Swing Beam 2 Stroke Diesel for the Automotive Engine” SAE Paper 830315
- Gray, C. 1988 “A Review of Variable Valve Timing” SAE Paper 880386
- Freudenstein, F. Maki, E.R. Tsai Lung-Wen 1988 “The Synthesis and Analysis of Variable Valve-Timing Mechanisms for Internal-Combustion Engines” SAE Paper 880387
- Ahmad, T. Theobald, M.A. 1989 “A Survey of Variable-Valve-Actuation Technology” SAE Paper 891674
- Dresner, T.L. Barkan, P. 1989 “A Review and Classification of Variable Valve Timing Mechanisms” SAE Paper 890674
- Dresner, T.L. Barkan, P. 1989 “A Review of Variable Valve Timing Benefits and Modes of Operation” SAE Paper 891676
- Tuttle, J.H. 1982 “Controlling Engine Load by Means of Early Intake-Valve Closing” SAE Paper 820408
- Saunders, R.J. Rabia, S.M. 1986 “Part load efficiency in gasoline engines” Practical limits of efficiency of engines . London Mechanical Engineering Publications for The Institution of Mechanical Engineers 55 62
- Basiletti, J.C. Blackburne, E.F. 1966 “Recent Developments in Variable Compression Ratio Engines” SAE Paper 660344