Cylinder and method for manufacturing a cylinder for an internal combustion engine

摘要

A cylinder and a method for manufacturing a cylinder for an internal combustion engine is provided which avoids the generation of a step portion at the scavenging port without necessitating enhanced precision of the positioning of the working tools or the working location. A raw cylinder body is cast-molded with the scavenging port portion thereof being left closed. Subsequently, this closed scavenging port portion is cut out (or opened) by means of cutting work, etc. The cutting out of the closed scavenging port portion is performed by widening the cylinder bore side thereof at predetermined angles to the planes of the inner wall of the hollow scavenging passageway formed contiguous to the closed scavenging port portion.