Abstract
It is assumed that the reader of this chapter has a basic understanding of the principles of operation of the two-stroke cycle engine and of the many mechanical variations which can occur on this simplest of all engine themes. It cannot be assumed that the reader, unless he is actively involved in the design, development or research of two-stroke engines, will be aware of the many problems which beset the progress of this type of power unit. For example, as the working cylinder has a compression and combustion process taking place within it upon every crankshaft revolution, it follows that some 50% of the cycle will be occupied by that firing process. It follows equally that, as combustion produces exhaust gas from the original air and fuel, the remaining half of the cycle must be used to remove the exhaust gases and replace them in the working cylinder by fresh air and, either simultaneously or eventually, fuel. As the working cylinder pressure varies from about one to many tens of atmospheres during this action, clearly the cylinder filling and emptying process is very dynamic and is conducted in an unsteady manner. Rather than use my own words at this point, I will quote the quite classic words of Hopkinson1 given in 1914:
‘The performance of 2-cycle internal combustion engines is determined very largely by the efficiency or otherwise of the process of charging. In the course of less than one quarter of a revolution the products of combustion resulting from the previous explosion have to be replaced as far as possible by the fresh charge of air, or of gas and air, which is blown in through the inlet valves and drives before it through the open exhaust ports the exhaust gases. Inevitably some mixing occurs and some of the fresh charge or of the scavenging air passes away to the exhaust and is wasted. On the amount of this waste depends very largely the performance of the engine. Its economy suffers to the extent of the waste of fuel.’
‘Is there anyone so wise to learn by the experience of others?’ (Voltaire)
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Hopkinson, B., The charging of two-cycle internal combustion engines. Trans. N E Coast Inst. Engrs Shipbldrs, 30 (1914) 433.
Bird, A. L., Oil Engines. Methuen, London, 1923.
Taylor, C. F. & Rogowski, A. R. Scavenging the two-stroke engine. Trans. SAE, 62 (1954) 487.
Kadenacy, M., British Patents 431856, 431857 etc.
Weaving, J. H., Two-strokes and turbines. Proc. Inst. Mech. Engrs. 183 (October 1968); Discharge of exhaust gases in two-stroke engines. Proc. Inst. Mech. Engng, 161 (1949) 98.
Johnston, S. C., A characterisation of unsteady gas distilled from a vessel. Sandia Laboratories, Jan. 1975.
Carter, H. D., Loop scavenged diesel engine. Proc. Inst. Mech. Engrs 154 (1946) 386.
Giffen, E., Rapid discharge of a gas from vessel into atmosphere. Engineering, 150 (1940) 139.
Mucklow, G. F. & Bannister, F. K. Wave action following sudden release of compressed gas. Proc. Inst. Mech. Engrs. 159 (1948) 269.
Jenny, E., Unidimensional transient flow with consideration of friction, heat transfer and change of section. Brown Boveri Review, 37(11) (1950) 447.
De Haller, R., The application of a graphic method to some dynamic problems in gases. Sulzer Tech. Rev. 1 (1945) 6.
Wallace, F. J. & Mitchell, R. W. S., Wave action following the sudden release of air through an engine port system. Proc. Inst. Mech. Engrs, 1B (1952–3) 343–63.
Wallace, F. J. & Boxer, G., Wave action in diffusers for exhaust pipe systems, with special reference to the scavenging of two-stroke engine. Proc. Inst. Mech. Engrs, 170(39) (1956) 1131–56.
Wallace, F. J. & Nassif, M. H., Air flow in a naturally aspirated two-stroke engine. Proc. Inst. Mech. Engrs, 168(18) (1954) 515–41.
Benson, R. S., Garg, R. P. & Woollatt, D., A numerical solution of unsteady flow problems. Int. J. Mech. Engng Sci., 6(1) (1964) 117–44.
Schweitzer, P. H., Scavenging of Two-stroke Cycle Diesel Engines. Macmillan, New York, 1949.
Naitoh, H. & Taguchi, M., Some development aspects of two-stroke cycle motorcycle engines. Trans. SAE 660394, 1966.
Naitoh, H. & Nomura, K., Some new development aspects of two-stroke cycle motorcycle engines. Trans. SAE 710084, 1971.
Blair, G. P., Further developments of a 500cc single cylinder 2-cycle motorcycle engine for motorcycle racing and moto-cross applications. Trans. SAE 740745, 1974.
Bannister, F. K., Pressure waves in gases in pipes. Ackroyd Stuart Memorial Lectures, University of Nottingham, 1958.
Annand, W. J. D. & Roe, G. E., Gas Flow in the Internal Combustion Engine. G. T. Foulis, Yeovil, England, 1974.
Blair, G. P. & Johnston, M. B., Simplified design criteria for expansion chambers for two-stroke gasoline engines. Trans. SAE 700123, 1970.
Blair, G. P. & Cahoon, W. L., A more complete analysis of unsteady gas flow through a high specific output two-cycle engine. Trans. SAE 720156, 1972.
Blair, G. P. & Ashe, M. C, The unsteady gas exchange characteristics of a two-cycle engine. Trans. SAE 760644, 1976.
Blair, G. P., Prediction of two-cycle engine performance characteristics. Trans. SAE 760645, 1976.
Blair, G. P., Hinds, E. T. & Fleck, R., Predicting the performance characteristics of two-cycle engines fitted with reed induction valves. Trans. SAE 790842, 1979.
Hinds, E. T. & Blair, G. P., Unsteady gas flow through reed valve induction systems. Trans. SAE 780766, 1978.
Benson, R. S., Woollatt, D. & Woods, W. A., Unsteady flow in simple branch systems. Proc. Inst. Mech. Engrs, 178 (Pt. 31 iii, No. 10) (1963–4) 21.
Bingham, J. F. & Blair, G. P., An improved branched pipe model for multi-cylinder automotive engine calculations. Proc. Inst. Mech. Engrs, 199 (Dil) (1984–5) 65–77.
Blair, G. P. & Spechko, J. A., Sound pressure levels generated by internal combustion engine exhaust systems. Trans. SAE 720155, 1972.
Blair, G. P. & Coates, S. W., Noise produced by unsteady exhaust efflux from an internal combustion engine. Trans. SAE 730160, 1973.
Coates, S. W. & Blair, G. P., Further studies of noise characteristics of internal combustion engine exhaust systems. Trans. SAE 740713, 1974.
Roe, G. E., An empirical approach to motorcycle silencing. Trans. SAE 770188, 1977.
Jones, A. D. & Brown, G. L., Determination of two-stroke engine exhaust noise by the method of characteristics. J. Sound Vib., 82(3) (1982) 305–27.
Mattavi, J. N. & Amman, C. A., Combustion Modelling in Reciprocating IC Engines, Proceedings of a Symposium Held at General Motors. Plenum Press, New York, 1980.
Sweeney, M. E. G., Kenny, R. G., Swann, G. B. & Blair, G. P., Single cycle gas testing method for two-stroke engine scavenging. Trans. SAE 850178, 1985.
Blair, G. P. & Kenny, R. G., Further developments in scavenging analysis for two-stroke engines. Trans. SAE 800038, 1980.
Jante, A., Scavenging and other problems of two-stroke cycle spark-ignition engines. Trans. SAE 680468, 1968.
Blair, G. P., Studying scavenge flow in a two-stroke cycle engine. Trans. SAE 750752, 1975.
Sanborn, D. S., Blair, G. P., Kenny, R. G. & Kingsbury, A. H., Experimental assessment of scavenging efficiency of two-stroke cycle engines. Trans. SAE 800975, 1980.
Sammons, H., A single-cycle test apparatus for studying loop scavenging in a two-stroke engine. Proc. Inst. Mech. Engrs, 161 (1949) 233–42.
Sweeney, M. E. G., Swann, G. B., Kenny, R. G. & Blair, G. P., Computational fluid dynamics applied to two-stroke engine scavenging. Trans. SAE 851519, 1985.
Spalding, D. B., A general purpose computer program for multidimensional one and two-phase flow. Mathematics and Computers in Simulation, 23 (1981) 267–76.
Blair, G. P., Kenny, R. G., Smyth, J. G., Sweeney, M. E. G. & Swann, G. B., An experimental comparison of loop and cross-scavenging of the two-stroke cycle engine. Trans. SAE 861240, 1986.
Yamagishi, G., Suto, T. & Iwasa, W., A study of two-stroke cycle fuel injection engine for exhaust gas purification. Trans. SAE 720195, 1972.
Pichard, J., Two-cycle stratified charge engine. Fourth International Symposium on Automobile Propulsion, 17–22 April 1977, Washington DC, by ERDA.
Vieilledent, E., Low pressure electronic fuel injection system for two-stroke engines. Trans. SAE 780767, 1978.
Douglas, R. & Blair, G. P., Fuel injection of a two-stroke cycle spark ignition engine. Trans. SAE 820952, 1982.
Onishi, S., Jo, S. H., Jo, P. D. & Kato, S., Multi-layer stratified scavenging (MULS)—a new scavenging method for two-stroke engine. Trans. SAE 840420, 1984.
Blair, G. P., Hill, B. W., Miller, A. J. & Nickell, S. P., Reduction of fuel consumption of a spark ignition two-stroke cycle engine. Trans. SAE 830093, 1983.
Hill, B. W. & Blair, G. P., Further tests on reducing fuel consumption with a carburetted two-stroke cycle engine. Trans. SAE 831303, 1983.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1990 Elsevier Science Publishers Ltd
About this chapter
Cite this chapter
Blair, G.P. (1990). The Two-stroke Engine: Crankcase Compression Type. In: Weaving, J.H. (eds) Internal Combustion Engineering: Science & Technology. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-0749-2_3
Download citation
DOI: https://doi.org/10.1007/978-94-009-0749-2_3
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-010-6822-2
Online ISBN: 978-94-009-0749-2
eBook Packages: Springer Book Archive