Abstract: In an air compression internal combustion engine having at least one cylinder, a combustion chamber formed in the cylinder and delimited at its longitudinal ends by a piston and a cylinder head which covers the cylinder, two intake valves and two exhaust valves per cylinder are installed in the cylinder head so as to be inclined at a valve angle ? and ?, respectively, in the range of 2° to 9° relative to a cylinder head longitudinal central plane (10), the valves each have a valve diameter Dintake and Dexhaust which is 30% to 40% of the cylinder diameter Dcylinder, the valve heads are disposed at a distance from the cylinder wall which delimits the combustion chamber, and webs of a predefined width are provided between adjacent valves of a cylinder, and the valve heads have sections which protrude into the combustion by a predetermined limited amount.