Renault 12R
| Industry | Automotive and aerospace engineering |
|---|---|
| Founded | 1899 |
| Headquarters | France |
The Renault 12R was an air-cooled, inverted V12 aircraft powerplant engineered by the French company Renault during the 1930s. This engine essentially merged two six-cylinder Renault 6Q units onto a single crankshaft. Standard production versions produced between , while a specialized high-performance model designed for the Caudron C.712 racing plane achieved . Out of the total 325 engines manufactured, more than one-third equipped the Caudron C.714 light fighter, which operated with both the French Air Force and the Polish Air Forces in France and Great Britain during the early stages of World War II.
Design and development
Conceived in the 1930s, the 12R took inspiration from the well-regarded Renault Bengali (6Q) engine, utilizing similar steel manufacturing methods. It evolved from a 4.46-liter test engine that combined two inline six-cylinder units on a single crankshaft, preserving their original bore and stroke measurements. The engine featured forged steel cylinders and pistons mounted on an eight-bearing crankshaft, all enclosed within an aluminium alloy crankcase treated with a magnesium coating. Performance was boosted by a centrifugal supercharger located at the rear of the engine. Both left- and right-handed rotation variants were produced, distinguished by their propeller rotation directions.
Intended for use in both civilian and military aircraft, the initial power rating in 1935 stood at . However, most engines produced—290 out of 325—were of the 12Rc variant introduced in 1939. Among these, 120 powered the Caudron C.714 light fighter deployed during World War II. Additionally, 35 units were delivered to the Polish Air Force operating in France, and six were supplied to Finland’s air service (though these were never engaged in combat). The highest-output model, known as the 12R Spécial (introduced in 1937), generated at 3,250 rpm and was installed in the single-seat Caudron C.712 racing aircraft derived from its fighter counterpart.
Variants
- Renault 12R
- Renault 12Rb
- Renault 12Rc
- Renault 12Rm
- Renault 12Ro
- Renault 12R-00
- Left-hand rotation
- Renault 12R-01
- Right-hand rotation
- Renault 12R-02
- Renault 12R-03
- Renault 12R-09
- Renault 12R Spécial
Applications
- Caudron C-446
- Caudron C.560
- Caudron C.581
- Caudron C.710
- Caudron C.712
- Caudron C.714
- Caudron C.870
- Dewoitine D.720
- Dewoitine D.750
- SNCAC NC-600 (prototype only)
- Romano R.110
Specifications (12R-00)
{{pistonspecs| |ref=Aircraft Engines of the World |type= Air-cooled V12 piston engine with inverted configuration |bore= |stroke= |displacement= |length= |width= |height= |weight= |valvetrain= Two overhead valves per cylinder actuated by pushrods |supercharger= Single-speed centrifugal supercharger |fueltype= Petrol with an octane rating of 87 |coolingsystem= Air-cooled |power=
- Take-off power: at 2,500 rpm
- Cruise power: at 2,500 rpm at
- Military power: at 2,100 rpm at