The Renault 12R was an

air-cooled Air-cooled engines rely on the circulation of air directly over heat dissipation fins or hot areas of the engine to cool them in order to keep the engine within operating temperatures. In all combustion engines, a great percentage of the heat ge ...

inverted

V12 V12 or V-12 may refer to: Aircraft * Mil V-12, a Soviet heavy lift helicopter * Pilatus OV-12, a planned American military utility aircraft * Rockwell XFV-12, an American experimental aircraft project * Škoda-Kauba V12, a Czechoslovak experim ...

aircraft engine developed by the French engineering company

Renault Groupe Renault ( , , , also known as the Renault Group in English; legally Renault S.A.) is a French multinational automobile manufacturer established in 1899. The company produces a range of cars and vans, and in the past has manufactured ...

in the 1930s. The design was based on mounting two 6Q six-cylinder engines on a single crankshaft. In production, the engine was rated between , although a high performance version built for the sole

Caudron C.712 The C.710 were a series of light fighter aircraft developed by Caudron-Renault for the French Air Force just prior to the start of World War II. One version, the C.714, saw limited production, and were assigned to Polish pilots flying in Fran ...

racing special produced . More than one third of production went to power the

Caudron C.714 The C.710 were a series of light fighter aircraft developed by Caudron-Renault for the French Air Force just prior to the start of World War II. One version, the C.714, saw limited production, and were assigned to Polish pilots flying in Franc ...

light fighter that fought in the early stages of

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

for the French and

Polish Air Forces The Polish Air Force ( pl, Siły Powietrzne, , Air Forces) is the aerial warfare branch of the Polish Armed Forces. Until July 2004 it was officially known as ''Wojska Lotnicze i Obrony Powietrznej'' (). In 2014 it consisted of roughly 16,425 mil ...

Design and development

The 12R was developed by Renault in the 1930s. The design was derived from the successful Renault Bengali, using the same construction techniques and being of essentially steel construction. It was based on the 4.46, a test engine developed by mounting two 6Q six-cylinder engines on the same

crankshaft A crankshaft is a mechanical component used in a piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating shaft containing one or more crankpins, that are driven by the pistons via the connecting ...

. The engine retained the bore and stroke of the smaller engine. The

cylinder A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base. A cylinder may also be defined as an infin ...

s and

piston A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tig ...

s were made of forged steel and connected in pairs to an eight bearing crankshaft. The

crankcase In a piston engine, the crankcase is the housing that surrounds the crankshaft. In most modern engines, the crankcase is integrated into the engine block. Two-stroke engines typically use a crankcase-compression design, resulting in the fuel/a ...

was made of aluminium alloy coated with magnesium. A centrifugal

supercharger In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. The current categorisation is that a supercharger is a form of forced induct ...

was mounted to the rear. The engine was produced in both right handed and left handed versions, the difference being the direction of

propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...

rotation. Designed to be fitted to a range of aircraft, both civil and military, the engine was originally rated at when first introduced in 1935. However, the majority manufactured, 290 out of a total production of 325, were the 12Rc introduced in 1939. Of these, 120 powered the

light fighter that served in

. In addition to examples of the aircraft ordered the

French Air Force The French Air and Space Force (AAE) (french: Armée de l'air et de l'espace, ) is the air and space force of the French Armed Forces. It was the first military aviation force in history, formed in 1909 as the , a service arm of the French Army; ...

, thirty-five were delivered to the

Polish Air Force The Polish Air Force ( pl, Siły Powietrzne, , Air Forces) is the aerial warfare branch of the Polish Armed Forces. Until July 2004 it was officially known as ''Wojska Lotnicze i Obrony Powietrznej'' (). In 2014 it consisted of roughly 16,425 mil ...

in France and a further six to the

Finnish Air Force The Finnish Air Force (FAF or FiAF; fi, Ilmavoimat, , Air forces; sv, Flygvapnet, , Air weapon) is one of the branches of the Finnish Defence Forces. Its peacetime tasks are airspace surveillance, identification flights, and production of Finnis ...

, although the latter were not used in combat. The most powerful version was the 12R Spécial of 1937 which produced at 3250 rpm and powered the single C.712 racing aircraft derived from the fighter.

Variants

;Renault 12R: ;Renault 12Rb: ;Renault 12Rc: ;Renault 12Rm: ;Renault 12Ro: ;Renault 12R-00: LH rotation ;Renault 12R-01: RH rotation ;Renault 12R-02: ;Renault 12R-03: ;Renault 12R-09: ;Renault 12R Spécial:

Applications

* Caudron C-446 *

Caudron C.560 The Caudron C.560 Rafale II () was a French competition aircraft built in the mid-1930s. It was intended to participate in the Coupe Deutsch de la Meurthe race of 1935 and was powered by a Renault 12R The Renault 12R was an air-cooled invert ...

* Caudron C.581 * Caudron C.710 *

Caudron C.870 The Caudron C.870 was a training aircraft built by Caudron The Société des Avions Caudron was a French aircraft company founded in 1909 as the Association Aéroplanes Caudron Frères by brothers Gaston and René Caudron. It was one of the earli ...

* Dewoitine D.720 *

Dewoitine D.750 The Dewoitine D.750 was a prototype France, French twin-engined torpedo bomber. It was designed prior to the outbreak of the Second World War to operate from the aircraft carriers of the French Navy, but only a single example was completed, with d ...

Hanriot H.220 The SNCAC NC-600 was a prototype French twin-engined long-range fighter aircraft, developed by SNCAC from the earlier Hanriot H.220 fighter. The type never entered service, with development being ended by the French surrender in June 1940. Desi ...

(prototype only) *

Romano R.110 The Romano R.110 was a twin-engine 3-seat fighter aircraft, designed by Etienne Romano in the 1930s. A single prototype was built, but it was not successful, the Potez 630 being preferred. Design and description On 31 October 1934 the French A ...

Specifications (12R-00)

References

Citations

Bibliography

* * * * * * * * * * {{Renault aeroengines 1930s aircraft piston engines Air-cooled aircraft piston engines Inverted V12 aircraft engines 12R