Abstract: An internal combustion engine in which each cylinder has a plurality of inlet ports (17,19) and a plurality of outlet ports (14), each port being openable and closeable by means of a respective valve (12,13,11). The inlet and outlet valves (12,13,11) are disposed with their center lines substantially on opposite sides of a cylinder center plane (16) and angled generally towards said center plane (16). There are three, or possibly more, valves on at least one of said sides, arranged with two outer valves (12) separated by one, or possibly more, inner valve (13). The angle of inclination with respect to said center plane (16) for the outer valves (12) is less than or equal to the angle of inclination for the inner valve (13). The valves are preferably operated directly with a separate camshaft (18,20,15) being provided for each one or more valves inclined at the same angle.