The evinrude Johnson 4 rotor race motor

OMC (outboard motor company) built this 4 rotor race motor in 1974 to compete with mercury in formula 1. It was based off of their 2 rotor snowmobile engine and produced 260hp at a displacement of 2112cc. Since it was build by stacking 2 twin rotors it used a two peice eccentric shaft with one long bolt to clamp it all together. This was a weak point and cost OMC quite a few problems. All in all the engine was quite successful until 1976 when it was replaced by the OMC v6. A production version never made it to the public but there was twin and single rotor versions of this engine producing 100 and 50hp respectively. They were used as test engines but are believed to be destroyed. The 4 rotor engines are mostly believed to be destroyed with only a few ending up in museums.