Coates has been doing the rotary valve thing for a good while now. I think it is an incredible design. The price tag is outrageous though. Removing the reciprocating parts from the valvetrain easily doubles the engine's RPM capability. I didn't visit the link b/c I've drooled at that website a lot in the past but a 13k RPM small block ford isn't something you forget. I know he developed a six cylinder head on a M110. Wonder is he could whoop one up for a M103, heck, I couldn't afford it anyway.