Four cycle engine

摘要

A multiple valve internal combustion engine and specifically a cylinder head and valve operating mechanism therefore. The cylinder head is formed from a two part construction and an arrangement is provided for operating the valves that permits a maximum volume cooling jacket to be formed on the exhaust side of the cylinder head. The camshaft and tappet mechanism for operating the valves is formed in a second cylinder head portion and a port extends through both cylinder head portions for serving the combustion chamber of the cylinder head. Various cam drive arrangement including either gear or chain drives are also disclosed.