Cylinder head for four-cycle internal combustion engines

Abstract

A cylinder head for four-cycle internal combustion engines with a concave combustion space portion, in which are arranged one inlet and one exhaust valve each with a relatively small V-angle; the center axis of the inlet and exhaust valves are located in cross planes offset transversely to the V-angle; the spark gap of a spark plug is offset transversely to the exhaust valve and is arranged approximately in the cross plane of the inlet valve; the V-angle of the valves is pivoted toward the side of the inlet valve with respect to the associated cylinder center axis by an angle of about 2.degree. to about 10.degree.; the combustion space portion in the cylinder head has an approximately flat half streamline cross-sectional shape in the direction of the V-angle whereby the relatively high part of the combustion space portion is arranged within the area of the spark gap and of the exhaust valve; the relatively low portion of the combustion space part narrows in the opposite area containing the inlet valve and the adjacent projection of the associated cylinder bore in a flat wedge-shaped manner and/or into at least a partially circumferential edge squeeze gap.