The power stroke is hitting barely off center to the rotor. In terms of maximizing power wouldn't the vector of delivery need to be perpendicular to the motion of the rotor/crank? It seems like only a small percent of the energy would be used to turn the rotor because a lot of it will be pushing back on the trailing end. Also looks like there would be a lot of intake/exhaust overlap. I could be way off course though, I am still a student for a reason