The Present-Day Efficiency and the Factors Governing the Performance of Small Two-Stroke Engines

The paper deals with the present-day efficiency of small 50 cc, air cooled, two-stroke engines, showing the essential performance characteristics of utility engines and higher output engines. The problems arising when output is increased by modification of the cylinders and exhaust systems are discussed, as well as the degrees of accuracy required in the manufacture of power determining assemblies. Some of the essential technical considerations involved in engine designing are also discussed, and some of the studies carried out to prove the suitability of the exhaust system, combustion-chamber configuration, spark plug assembly, piston rings, and cylinder material are described.