It is simple and advisable as well as efficacious to improve the dynamic and economic properties of two-stroke motorcycle petrol engine by means of exhaust dynamic effect. In this paper, the exhaust pipe design method and the effect of some exhaust system factors on the exhaust dynamic effect are researched into by test for the exhaust systems of the two models of motorcycle engines.
Under several operating conditions, exhaust pressure waves are measured respectively at the different points on the exhaust pipes of variously designed sizes. Having analysed the measured exhaust pressure waves and the results simulatively calculated, the relative problems to reasonablely utilize the exhaust dynamic effect of two-stroke motorcycle petrol engines are discussed in some detail.
In author's view, the exhaust dynamic effect will be made good use of, and thereby engine performances will be much improved, provided all of the main sizes of exhaust pipe are carefully tuned and right matched with engine port timing and operating parameters in cylinder, so that the exhaust pressure wave shape is conformed or similar to the ideal pressure wave shape, therefore the best or better exhaust pipe design is brought into being.