US Patent 7216611 Cooling structure of cylinder block

A cooling structure of a cylinder block includes a water jacket portion which is provided so as to surround an entire outer periphery of the bore wall; a water jacket spacer which is inserted in the water jacket portion; and a gasket which is provided in an upper portion of the cylinder block, and which includes a hole leading to the water jacket portion. The water jacket portion is supplied with coolant. A distance between a center of the hole and an outer periphery of the cylinder block is shorter than a distance between a center of the water jacket spacer in a thickness direction and the outer periphery of the cylinder block. In the cooling structure, the cylinder block can be uniformly cooled.