Abstract: The invention relates to a rotary valve control system for internal combustion engines and reciprocating pumps. A rotationally symmetrical, dome-shaped, drivable rotary valve is arranged in the cylinder head of the engine. In the cylinder head there is in the region of the inlet duct and the outlet duct at least one rotatable gasket ring which is provided with a drive. The rotary valve is linked to the drive thereof by means of spring means acting in the peripheral direction, and the gasket rings are in the form of thrust bearings and arranged on that side of the rotary valve which faces away from the cylinder.