ENGINE, CYLINDER BODY MEMBER, AND VEHICLE

摘要

The present invention addresses the problem of providing an engine capable of more effectively inhibiting the formation of scuffs in the vicinity of top dead centre. This engine is provided with a piston part, and a cylinder body part having a sliding surface along which the piston part slides. The engine is characterized in that: the cylinder body part is formed from an Al alloy having an Si content of at least 16 mass%, and includes primary Si crystal grains having an average crystal grain size of 8-50 µm inclusive, eutectic Si crystal grains having an average crystal grain size smaller than that of the primary Si crystal grains, and an Al alloy base material; and, in the sliding surface, in an area comprising at least 1/4 of the upper side of the sliding surface, the primary Si crystal grains and the Al alloy base material are exposed so as to come into contact with the piston part, and a plurality of substantially parallel linear grooves, which have a depth of at least 1/3 of the upper limit value of the range of the eutectic Si crystal grain sizes in the grain size distribution of the Si crystal grains in the cylinder body part, are formed at a pitch greater than the average crystal grain size of the primary Si crystal grains, and have sections which pass between adjacent primary Si crystal grains.