An engine with intake and exhaust valves that may be controlled with a circular cam lobe is provided. The rotating axis of the circular cam lobe is offset from the physical center of the cam lobe. This permits the cam lobe to impart a reciprocal opening and closing of the valve. To maintain the valve in the closed position, the interconnection between the cam lobe and the valve 12 may have a spring which is compressed to allow the valve to remain closed for a set duration of time while the cam lobe continues to rotate.