Wankel Model Engine 1973 Ad. A see-through working motorized scale model of the revolutionary rotary engine that powers the Mazda! Model includes every moving part and non-moving part of the real thing. The same engine General Motors paid 50 million dollars for production rights - and now you can see how it works - in this see-thru kit thats a fully operational 1/5 scale model. Complete Mazda Car Kit! 130-pieces. Gift House.