Cylinder block of internal combustion engine

摘要

In a cylinder block of an internal combustion engine, crank caps are bolted and a crankshaft is rotatably supported by the crank caps. The cylinder block includes bulkheads which divide an internal space of a crankcase into sub-sections for respective cylinders of the engine. Breathing holes are formed in each of the bulkheads and allow the sub-sections of the crankcase to communicate with each other via the breathing holes. Crank cap holes are formed in a bottom of each of the bulkheads. Bolts are fastened to the crank cap holes to fix the crank caps to the bulkheads. The crank cap holes are threaded holes which extend from the bottom of each of the bulkheads and are open to the breathing holes.