OBERURSEL UR.II

The Oberursel Ur.II was a German WW1 rotary aero engine air cooled with 9 cylinders. Its displacement was 16.3 liters, and the weight of the dry engine did not exceed 150 kilograms. The maximum power generated by this engine reached 111-112 HP. The Ur.II engine was produced at Motorenfabrik Oberursel, which initially specialized in the production of cars and railway locomotives. But as early as 1908, the company acquired the license to produce the French Gnome aircraft engine, and in 1913 - to produce the Le Rhone 9C. With the outbreak of World War I, the factory very quickly switched to mass production of aircraft engines, and one of the first engines produced by Oberursel was the Ur.II model, which in fact was a faithful copy of the French Le Rhone 9J. After some minor technical improvements, the engine turned out to be very successful, becoming one of the best - if not the best - German Rotary Engine of the Great War! It served as a drive for, for example, the Fokker Dr.I.