A four cycle internal combustion engine has a cylinder, a piston slidable therein, intake and exhaust valves, a pair of intake passages, and an exhaust passage. There are at least three intake valves, and the intake passages are connected so that each discharges to an intake valve adjacent to the central axis of the cylinder, and in addition also to respective other intake valves on the opposite sides of an axis of symmetry. The plural intake valves, and if desired also the plural exhaust valves, are simultaneously activated because they are connected to a respective plate that is contacted by an actuating cam. The respective valve stems are inclined in a V shaped configuration to accommodate a plug between them, and a central one of the valves can be offset (advanced) into the combustion chamber to improve the combustion characteristics.