The Rotating Cylinder Valve Engine is a novel 4 cycle engine that is a practical alternative to conventional 2 & 4 stroke designs, in particular for small capacity single cylinder applications. It is primarily intended to address applications where emissions legislation is forcing manufacturers to abandon the traditional carbureted 2 stroke. It has particular benefits for the moped/ light motorcycle market.

The engine operates on a simple principle. The cylinder liner is rotated around the piston at half engine speed via a pair of bevel gears. A port in the side of this cylinder indexes with inlet & exhaust ports in the surrounding casing. This rotary valve serves the cylinder as the engine cycles through the conventional 4 stroke cycle.