Abstract: A mixture-compressing spark-ignited four-stroke internal combustion engine having a combustion chamber bounded by the piston and the cylinder head, and inlet and exhaust valves, the valve openings of which are offset in plan view in the longitudinal direction of the engine with respect to a transverse plane of the cylinder and the valve stems of which form an acute angle when projected onto the transverse plane of the cylinder, and a squish area opposite a spark plug and parts of the inlet valve opening being masked and supplied with a mixture by a swirl inlet passage, the swirl inlet passage supplying a mixture to the inlet valve opening tangentially, a spark plug being disposed close to the center of the cylinder on the side facing the inlet valve opening, a squish area being provided opposite the spark plug amounting to between 5% and 15% of the cylinder cross-sectional area, and the inlet valve opening being masked on its flow downstream area toward the outer periphery of the cylinder by a downward projec

Abstract: A device for the angular adjustment of a camshaft of a combustion engine according to speed and load conditions and to the angular position of the camshaft with respect to a driving wheel being controlled by an adjustable mechanism. The technical problem is the angular adjustment of the single or multiple camshafts with respect to the crankshaft according to speed and load conditions. Tooth pulses, or counting pulses, corresponding to the angular position of the crankshaft (2) and reference pulses corresponding to a particular angular reference position (singular tooth) are generated by a transducer, or pulse generator, controlled by the toothed ring associated with the crankshaft and the ignition circuit (13). An address counter (10) is reset by the reference pulses and incremented by the tooth pulses so that the output of the counter provides digital address signals corresponding to the actual angular position of the crankshaft (2).