The Le Rhône 9J is a nine-cylinder rotary aircraft engine produced in France by Gnome et Rhône. Also known as the Le Rhône 110 hp in a reference to its nominal power rating, the engine was fitted to a number of military aircraft types of the First World War. Le Rhône 9J engines were produced under license in Great Britain by W.H. Allen Son & Company of Bedford, and in Germany by Motorenfabrik Oberursel where it was sold as the Oberursel Ur.II.[1]
In common with other Le Rhône series engines, the 9J featured highly visible copper induction pipes and used a single push-pull rod to operate its two overhead valves.[2] The main visual difference between the 9J and the earlier, less powerful Le Rhône 9C engine is that the copper intake manifold tubing (with round section lower ends) on the 110 hp 9J is attached to the crankcase behind the cylinders, whereas on the 9C (80 hp) the intake manifolds (with rectangular lower ends) are fully visible from the front.
Examples of Le Rhône 9J engines are on public display in aviation museums, with several remaining airworthy, powering restored and authentic reproductions of vintage aircraft.
A Bristol M.1 replica, owned and operated by the Shuttleworth Collection remains airworthy and is powered by a Le Rhône 9J engine.[3] The collection's airworthy Avro 504 is also powered by a 110 hp Le Rhône rotary engine.[4] The reproduction Avro 504 at Old Rhinebeck Aerodrome has also flown with an original Le Rhone 9J powerplant,[5] as was Cole Palen's first reproduction Fokker Dr.I triplane (now retired) for Old Rhinebeck's airshows in the 1960s, bearing American registration N3221.[6]
A full-scale Nieuport 11 replica built by Walt Pfeifer and Joe Pfeifer in the early 1960s, now operated by The Vintage Aviator Limited, flies in New Zealand with a Le Rhone 9C.[7]
Preserved Le Rhône 9J engines are on public display at the following museums: