Patent ID: 6799540
Filing Date: 2004-10-05
Classification: F02B,F02F

Abstract:
A multi cylinder internal combustion engine comprising a cylinder head internally defining exhaust passages extending from a plurality of combustion chambers defined in part by said cylinder head, said exhaust passages converging into a converging area also internally defined in said cylinder head, wherein:an upper water jacket and a lower water jacket are formed above and below said exhaust passages, and said lower water jacket has a greater volume than said upper water jacket; wherein said converging area and said exhaust passages are defined at least in part by an exhaust passage wall extending laterally from said cylinder head defining an arched profile in a plane perpendicular to a cylinder axial line, and laterally outer walls of said upper and lower water jackets extend adjacent to said exhaust passage wall with a thick walled portion formed between said exhaust passage wall and at least one of said laterally outer walls of said upper and lower water jackets; and wherein said thick walled portion consists of a narrow strip extending substantially in parallel with a crankshaft of said engine along said arched profile.