Abstract: A valve system for controlling the opening and closing of the intake and exhaust ports of the internal combustion engine's cylinders consists of a shutter valve assembly which opens and closes a row of openings registering with the engine's combustion chamber. The shutter assembly includes a movable shutter ring having a plurality of shutter openings which either register with the intake ports during the intake cycle of the internal combustion engine or with the exhaust ports during the exhaust cycle of the internal combustion engine. A controller regulates the rotation of the shutter ring so that the appropriate ports are in communication with the cylinder for proper intake of fluid and air and the exhaust of fumes from the combustion.