Internal combustion engine

摘要

An internal combustion engine which comprises an engine body, and an air-intake side protective cover disposed at an air-intake side of the engine body, wherein the air-intake side protective cover is provided on the outer surface thereof with recessed grooves. The internal combustion engine may further comprise an exhaust side protective cover which is disposed in opposite to the air-intake side protective cover with the engine body being interposed therebetween and the recessed grooves are made to have substantially the same width and interval as those of a suitable number of heat radiating slit-like through-holes formed parallel with each other in the exhaust side protective cover.