Le Rhône 9J

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.[1]

Le Rhône 9J.jpg
A Le Rhône 9J on museum display
Type Rotary engine
National origin France
Manufacturer Gnome et Rhône
First run 1916
Number built 953 (British production)

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.

The Le Rhône 9J engine was manufactured under license in Germany by Motorenfabrik Oberursel and sold as the Oberursel Ur.II.

Examples of Le Rhône 9J engines are on public display in aviation museums, with several remaining airworthy, powering both restored vintage aircraft and authentic reproductions of such aircraft.


Le Rhône 9Ja
(1916) 110 hp (82 kW), nine-cylinder rotary engine. 953 built by W.H. Allen Son & Co.
Le Rhône 9Jb
(1916) 130 hp (97 kW), nine-cylinder rotary engine.
Le Rhône 9Jby
(1916) 130 hp (97 kW), nine-cylinder rotary engine.
Le Rhône M-2
production in the USSR post-WWI, 120 hp (89 kW)


Le Rhône 110 hp engine installed in an airworthy Avro 504 biplane
Le Rhône 9Ja
Le Rhône 9Jb
Le Rhône 9Jby
Oberursel Ur.II


The Addems-Pfeifer Nieuport 11 replica pictured at Porterville, CA in 1962.

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]

Engines on displayEdit

Preserved Le Rhône 9J engines are on public display at the following museums:

Specifications (Le Rhône 9Ja)Edit

Le Rhône 9J crankshaft, pistons, and connecting rods

Data from Lumsden.[1]

General characteristics

  • Type: Nine-cylinder, single-row rotary engine
  • Bore: 112 mm (4.41 in)
  • Stroke: 170 mm (6.63 in)
  • Displacement: 15 L (911.4 cu in)
  • Diameter: 100.5 cm (39.6 in)
  • Dry weight: 146.5 kg (323 lb)


  • Valvetrain: Cam-operated single rocker for both inlet and exhaust valves
  • Oil system: Castor oil, total loss
  • Cooling system: Air-cooled


See alsoEdit

Comparable engines

Related lists



  1. ^ a b Lumsden 2003, p. 161.
  2. ^ Gunston 1989, p. 93.
  3. ^ Shuttleworth Collection - Bristol M.1C Retrieved: 16 November 2010
  4. ^ CAA G-INFO - Avro 504, G-ADEV Retrieved: 16 November 2010
  5. ^ Old Rhinebeck Aerodrome - Avro 504 Retrieved: 20 January 2011
  6. ^ "Cole Palen's Old Rhinebeck Aerodrome — Fokker Dr.1 Triplane". oldrhinebeck.org. Old Rhinebeck Aerodrome. Archived from the original on March 2, 2014. Retrieved March 18, 2014.
  7. ^ "Nieuport 11 Bebe". The Vintage Aviator Limited. Retrieved May 18, 2017.


  • Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.
  • Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9

External linksEdit