Maier MM-6 Maier - Four Cylinder Axial Piston Gas EngineThe four cylinder axial piston gas engine with tumbling spider engine is based on the model of airplane engines tested in the 1930s and 1940s. These engines were of interest because they took up less front space than radial engines. The piezo high voltage ignition system built into the base is propelled by a drive belt from the engine shaft. The ignition, or rather, ignition point is controlled by a central distributor. Gas and rotation speed control