An improved profilometric technique for wear computation and its application in two-stroke engine cylinder liners

Abstract

The small two-stroke spark-ignited engine, operating on oil-lost-type lubrication, has a higher oil consumption and poorer durability than the four-stroke spark-ignited engine. The progressive wear of the cylinder liner leads to high blow-by and loss of power. The operating time to attain limiting wear defines the engine service life. Accurate measurement methods, which make it possible to determine not only the amount of wear but also its distribution, can play an important role in the understanding of the wear phenomenon. This paper describes the development of a wear-profile-computing technique by enhancing the capability of a surface-texture-measuring instrument. The technique was subsequently applied in computing wear profiles of two-stroke engine cylinder liners. The results indicate that the technique provides useful information for the analysis of worn surfaces. The magnitude of wear was also found to be relatively high in specific regions of the cylinder liner.