Abstract: A rotary internal combustion engine is provided with a central housing having a plurality of cylinders radially disposed around the housing. The cylinders are disposed about the housing such that reciprocal movement of pistons inside of the cylinders results from rotational movement of the central housing about a stationary center axis, so that the pistons are not brought to an instantaneous stop at a point in their cycle at which a 180.degree. change in direction occurs. By not having to overcome such inertial forces, a substantial increase in energy output is achieved. The rotating housing is mounted on supports to stabilize the engine and transmit rotational movement to a driven device. The exhaust output of the individual cylinders is directed outwardly to provide additional torque in the form of a jet action.