Eternal combustion engine

I developed a design for an engine that is about 80% efficient that has about a third of the weight requirements of a typical internal combustion engine. This is definitely outside the box as it has no intake or exhaust. It seems to me that if more innovation were achieved in the engines it would have multiple positive effects. It would be cheaper, less pollution, and safer to operate. With the addition of inertial canceling it is also much safer since less weight means less mass and thus less energy evolved in a collision. The designs for the future are no where near their limit of effectiveness and I find that vehicles are the most ridiculous design and it begs for death in its operation. I am investigating whether the engine would be usable as a free flight engine and perhaps that is the best solution if inertial canceling is incorporated.