Patent ID: 8225751

Claim:
A cooling water passage structure for an engine, comprising: an engine having cylinder axes arranged in a V-shape centering on a crankshaft; water jackets formed in respective cylinder blocks and respective cylinder heads of said engine; a thermostat case having a portion formed integrally with said cylinder blocks in a V-bank of said cylinder blocks; a cooling water inlet side connecting portion connecting a cooling water supply side line with a cooling water passage including said water jackets; and a cooling water outlet side connecting portion connecting a cooling water discharge side line with said cooling water passage including said water jackets; wherein said thermostat case, said cooling water inlet side connecting portion, and said cooling water outlet side connecting portion are disposed on one side of said engine with respect to the axial direction of said crankshaft, wherein said cooling water inlet side connecting portion and said cooling water outlet side connecting portion are arranged on a centerline to align with each other as viewed from the axial direction of said crankshaft, and wherein the centerline divides the V-bank of said cylinder blocks in two.