Abstract: A rotary piston engine is disclosed. In one aspect, the engine includes a rotary piston rotating in a housing. The engine also includes a piston flank wall extending at least between two apex edges adjacent on the circumferential wall of the piston. The engine further includes a combustion chamber formed between the piston flank wall, an inner circumferential wall of the housing, and inner side walls of the housing, wherein the spark plug is connected to the combustion chamber by at least one spark plug channel. The spark plug channel has a substantially circular, elliptical or slot-like formed cross-section and the spark plug is arranged in a spark plug cavity having a larger diameter than the spark plug channel. The volume of the spark plug cavity is arranged relatively to thee spark plug channel substantially at the rear side, seen in the direction of rotation.

Abstract: A liquid-cooled internal combustion engine which includes a cylinder housing for at least one cylinder and at least one cylinder head, with the at least one cylinder in the cylinder housing being enclosed by a cooling jacket and with a bottom partial cooling chamber adjacent to a fire deck and an upper partial cooling chamber which is flow-connected with the same via at least one transfer opening being arranged in the cylinder head which is connected with the cylinder housing, with a coolant outlet which can be connected with a pressure sink originating from the bottom partial cooling chamber.

Abstract: A liquid-cooled internal combustion engine which includes a cylinder housing for at least one cylinder and at least one cylinder head, with the at least one cylinder in the cylinder housing being enclosed by a cooling jacket and with a bottom partial cooling chamber adjacent to a fire deck and an upper partial cooling chamber which is flow-connected with the same via at least one transfer opening being arranged in the cylinder head which is connected with the cylinder housing, with a coolant outlet which can be connected with a pressure sink originating from the bottom partial cooling chamber.