INTERNAL COMBUSTION ENGINE WITH CENTRALLY LOCATED SPARKPLUGS

摘要

An internal combustion engine includes a cylinder head having attachment surfaces which lie in the same plane and to which a head cover and an intake manifold are attached, respectively. The attachment surfaces can therefore be machined simultaneously in one process with a common cutting tool. The internal combustion engine also has a valve operating mechanism housed in a valve mechanism chamber in the cylinder head for actuating intake and exhaust valves. The valve mechanism chamber is defined by a pair of opposite trapezoidal end walls extending from the bottom of the valve mechanism chamber and a ceiling wall integrally interconnecting the upper ends of the trapezoidal end walls. The valve mechanism chamber has a pair of windows defined one on each side of the ceiling wall thereof between the trapezoidal end walls to provide access therethrough to the valve operating mechanism. The cylinder head has a plurality of cylindrical plug housings extending between the ceiling walls of the combustion chambers and the ceiling wall of the valve mechanism chamber for accommodating the spark plugs. The spark plugs are substantially aligned with the axes of the cylinders in the cylinder block. Head covers can easily be attached to and detached from the cylinder head separate from the plug housings.