The GRAUPNER aircraft engine is next to the OS-RE-49-PI and the OS-RE-49-PI-II the first rotary piston model engine produced in series for model making based on the principle developed by Dr. Felix Wankel.

In a two-arch trochoid (figure-of-eight-shaped housing), a three-arch rotor moves on a circular path and rotates around its own center. This planetary movement is controlled by the eccentric shaft, the hollow gear in the rotor and the fixed pinion in the engine housing. The intake and combustion chambers increase and decrease in size.

The intake fuel-air mixture is compressed and pushed into the combustion chamber, where it is ignited and can transfer its power to the eccentric shaft during expansion. The sealing strips prevent the gases from flowing from one chamber to the other. The inlet and outlet are controlled by slots, as in a two-stroke piston engine.

The engine can be continuously regulated over a wide speed range using the throttle carburetor. The associated silencer reduces the exhaust noise to a minimum without significantly affecting the performance. The mounting ring enables the engine to be attached quickly and securely to three points.

Other engines