Abstract

A compact dual ignition push rod actuated overhead valve internal combustion engine having in a preferred embodiment a 4 cylinder V-type arrangement of 60° bank angle provided with part-spherical combustion chambers having diagonally placed intake and exhaust ports controlled by valves actuated through push rods from a central camshaft and having dual spark plugs with diagonally placed gaps angularly alternating with the ports. The spark plugs extend from the combustion chambers through adjacent outer side and end walls of the cylinder head while the valve actuating push rods pass through openings between the combustion chamber and the cylinder head inner side wall in a compact arrangement for an engine having dual ignition fast burn combustion chambers.