In 1968 Sanville began building a series of Twin Cams using a new camshaft called the Super Special Equipment cam, or D-Type, that was based on the Coventry Climax FWA 3060 cam. Heads used in SSE engines were shaved by , boosting the compression ration to 10.3:1. The ignition was advanced slightly, and larger chokes and different jets were fitted to the Weber carburettors. Power was estimated to be , fully three years prior to the release of the Big Valve engine. Some SSE engines are said to have left the factory in Super Weber S/E Elans.