Duke Engines

The Duke Engine is an Advanced Internal Combustion Engine

delivering high Thermodynamic Efficiency, complete Fuel Flexibility, (runs on any suitable spark ignition fuel), Neglible 1st and 2nd order Vibration with huge Weight and Size savings.
It is a considerably less complex internal combustion engine and is suitable for Marine (inboard and outboard), Light Aircraft, Generator/Utility and Military applications.

http://www.dukeengines.com/