Le Rhône 9C

The Le Rhône 9C is a nine-cylinder rotary aircraft engine produced in France by Société des Moteurs Le Rhône / Gnome et Rhône. Also known as the Le Rhône 80 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 9C engines were also produced under license in Germany, Sweden and Great Britain by various companies,[1] and in the United States. The Swedish version built by AB Thulinverken was designated Thulin A. German production and development was carried out by Oberursel Moterwerken as the UR.I.

Le Rhone C RAFM.jpg
Le Rhône 9C engine installed in a Sopwith Pup at the Royal Air Force Museum London
Type Rotary engine
National origin France
Manufacturer Société des Moteurs Le Rhône / Gnome et Rhône
First run 1916
Number built 1,088 (British production)

Design and developmentEdit

In common with other Le Rhône series engines, the 9C featured copper induction pipes and used a single push-pull rod to operate its two overhead valves.[2] Unlike later engines, these were located on the front of the engine.

Examples of Le Rhône 9C engines are on view in aviation museums either installed in aircraft exhibits or as stand-alone displays. A few examples of the 9C engine remain airworthy both in Europe and North America, one powering a vintage Sopwith Pup biplane in England, and a small number of others having powered reproduction WW I-era aircraft at Old Rhinebeck Aerodrome and other American "living" aviation museums that fly their restored original engines in both similarly restored original, and airworthy reproduction period aircraft.


Le Rhône 9C on display at the Air Zoo


Both the restored Shuttleworth Collection's airworthy Sopwith Pup and the 1960s-built reproduction Pup of the Owl's Head Transportation Museum (originally from Old Rhinebeck Aerodrome) are each powered by 80 hp Le Rhône 9C rotary engines, and fly regularly throughout the summer months.[3][4] An operative Le Rhone 9C is shown at the Museo Nacional de Aeronautica in Buenos Aires Argentina.

Engines on displayEdit

A Le Rhône 9C is installed in the Sopwith Pup on display at the Royal Air Force Museum London. After renovation this aircraft flew for a brief period in the 1970s and is now retired.[5]

Specifications (Le Rhône 9C)Edit

Close-up view of a Le Rhône 9C showing the valve operating rods, front-side induction manifold (contrast with the Le Rhône 9J's rear mounted design) and manufacturer's data plate

Data from Lumsden.[1]

General characteristics

  • Type: Nine-cylinder, single-row rotary engine
  • Bore: 105 mm (4.13 in)
  • Stroke: 140 mm (5.51 in)
  • Displacement: 10.89 L (664.47 cu in)
  • Diameter: 94.5 cm (37.2 in)
  • Dry weight: 121.5 kg (268 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. 160.
  2. ^ Gunston 1989, p. 93.
  3. ^ CAA G-INFO - Sopwith Pup, G-EBKY Retrieved: 17 November 2010
  4. ^ Shuttleworth Collection - Sopwith Pup Retrieved: 06 April 2017.
  5. ^ Royal Air Force Museum London - Sopwith Pup, N5182- Full history Retrieved: 17 November 2010.


  • 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