Cylinder head cooling structure

Abstract

This invention relates to a cylinder head cooling structure for an air cooled internal combustion engine. The said cooling structure enhances the cooling effect on a cylinder head and oil flowing on a bottom wall by enlarging a cooling port while maintaining an oil return function. In a cylinder head cooling structure of the present invention, the combustion chamber is provided in a lower portion of the cylinder head and a valve train chamber isolated from the combustion chamber by a bottom wall provided in an upper portion of the cylinder head, a cam chain chamber is provided in a lateral portion of the cylinder head, an oil return passage is provided on the bottom wall and exhaust port is provided between the combustion chamber and the valve train chamber and in front portion of the cylinder head, characterized in that a cooling air introduction port is provided between the exhaust port and the bottom wall is slanted toward the cam chain chamber in a left-right direction of the vehicle.