The arguably wildest creation of Kelsey Martin was a motorcycle powered by a six-cylinder horizontally opposed air cooled engine out of a Corvair automobile. The engine was supercharged by a Latham roots type blower fed by four carburetors. The output of the engine was put through a special right angle drive gear box custom made by a tool and die maker who worked at Pratt& Whitney, so that a conventional but (very heavy duty) rear chain drive could be used.
A special Martin-fabricated frame incorporated a rigid rear and telescopic front forks.
Very few photos of the Unholy Six exist.