Patent ID: 7430993

Claim:
A cooling structure of an engine, comprising: a cooling water communication passage provided at a cylinder block-integrated crankcase of an engine with parallel multiple cylinders loaded by being tilted forward, the cooling water communication passage supplying cooling water to a water jacket from a water pump, wherein the cooling water communication passage extends in parallel with a crankshaft so as to divide cooling water into the water jacket corresponds to each cylinder at an opposite side of an exhaust pipe with respect to an axis of the cylinder, the cooling water communication passage is disposed at a substantially same distance from the crankshaft as a piston bottom dead center position which is disposed below a bottom end of the water jacket, a connecting portion provides fluid communication between the cooling water communication passage and the water jacket, the water pump is placed at a side wall of the crankcase located at a rear side from a crankshaft, and a downstream side cooling water pipe through which the cooling water discharged from the water pump is passed is connected to an intermediate portion of the cooling water communication passage.