Renault 12R

The 12R was developed by Renault in the 1930s.{{sfn|Gunston|1998|page=135}} The design was derived from the successful Renault Bengali, using the same construction techniques and being of essentially steel construction.{{sfn|Grey|Bridgman|1938}}{{sfn|Wilkinson|1945|page=58}} It was based on the 4.46, a test engine developed by mounting two 6Q six-cylinder engines on the same crankshaft.{{sfn|Ailes Anciennes Le Bourget}} The engine retained the bore and stroke of the smaller engine.{{sfn|Wilkinson|1945|pages=245–247}} The cylinders and pistons were made of forged steel and connected in pairs to an eight bearing crankshaft. The crankcase was made of aluminium alloy coated with magnesium. A centrifugal supercharger was mounted to the rear.{{sfn|Angle|1941|page=120}} The engine was produced in both right handed and left handed versions, the difference being the direction of propeller rotation.{{sfn|Wilkinson|1945|page=247}}

Designed to be fitted to a range of aircraft, both civil and military, the engine was originally rated at {{convert|450|hp|kW|lk=on}} when first introduced in 1935. However, the majority manufactured, 290 out of a total production of 325, were the {{convert|500|hp|kW|abbr=on|adj=on}} 12Rc introduced in 1939.{{sfn|Hartman|2015|page=31}} Of these, 120 powered the Caudron C.714 light fighter which served in World War II.{{sfn|Hartman|2015|page=32}} In addition to examples of the aircraft ordered the French Air Force, thirty-five were delivered to the Polish Air Force in France and a further six to the Finnish Air Force, although the latter were not used in combat.{{sfn|Angelucci|Matricardi|Cosentino|Tatangelo|1978|page=258}} The most powerful version was the 12R Spécial of 1937 which produced {{convert|730|hp|kW|abbr=on}} at 3250 rpm and powered the single C.712 racing aircraft derived from the fighter.{{sfn|Ailes Anciennes Le Bourget}}

;Renault 12R:{{convert|450|hp|kW|abbr=on}}{{sfn|Hartman|2015|page=22}}

;Renault 12Rb:{{convert|470|-|480|hp|kW|abbr=on}}{{sfn|Hartman|2015|page=31}}

;Renault 12Rc:{{convert|500|hp|kW|abbr=on}}{{sfn|Hartman|2015|page=31}}

;Renault 12Rm:{{convert|480|hp|kW|abbr=on}}{{sfn|Hartman|2015|page=32}}

;Renault 12Ro:{{convert|450|hp|kW|abbr=on}}{{sfn|Hartman|2015|page=22}}

;Renault 12R-00:{{convert|500|hp|kW|abbr=on}} LH rotation{{sfn|Wilkinson|1945|page=247}}

;Renault 12R-01:{{convert|500|hp|kW|abbr=on}} RH rotation{{sfn|Wilkinson|1945|page=247}}

;Renault 12R-02:{{convert|500|hp|kW|abbr=on}}{{sfn|Hauet|2002|page=202}}

;Renault 12R-03:{{convert|500|hp|kW|abbr=on}}{{sfn|Ailes Anciennes Le Bourget}}

;Renault 12R-09:{{convert|500|hp|kW|abbr=on}}{{sfn|Hauet|2002|page=229}}

;Renault 12R Spécial:{{convert|730|hp|kW|abbr=on}}{{sfn|Hartman|2015|page=32}}

• Caudron C-446{{sfn|Hartman|2015|page=32}}
• Caudron C.560{{sfn|Hartman|2015|page=32}}
• Caudron C.581{{sfn|Hartman|2015|page=32}}
• Caudron C.710{{sfn|Hartman|2015|page=32}}
• Caudron C.712{{sfn|Hartman|2015|page=32}}
• Caudron C.714{{sfn|Green|Swanborough|1994|page=111}}
• Caudron C.870{{sfn|Hauet|2002|page=229}}
• Dewoitine D.720{{sfn|Green|1967|page=22}}
• Dewoitine D.750{{sfn|Green|1967|page=25}}
• Hanriot H.220 (prototype only){{sfn|Green|Swanborough|1994|page=280}}
• Romano R.110{{sfn|Green|Swanborough|1994|page=503}}

{{pistonspecs|

|ref=Aircraft Engines of the World {{sfn|Wilkinson|1945|page=247}}

|type= 12-cylinder, air cooled V12 engine

|bore= {{convert|120|mm|in|abbr=on}}

|stroke= {{convert|140|mm|in|abbr=on}}

|displacement= {{convert|19|L|in3|0|abbr=on}}

|length= {{convert|2072|mm|in|abbr=on}}

|diameter=

|width= {{convert|680|mm|in|abbr=on}}

|height= {{convert|929|mm|in|abbr=on}}

|weight={{convert|439|kg|lb|abbr=on}}

|valvetrain= 2 x overhead valves per cylinder operated by pushrods

|supercharger= Single speed centrifugal compressor

|turbocharger=

|fuelsystem=

|fueltype= 87 Octane petrol

|oilsystem=

|coolingsystem= Air-cooled

|power=

• Take-off: {{convert|500|hp|kW|0|abbr=on}} at 2,500 rpm
• Cruise: {{convert|300|hp|kW|0|abbr=on}} at 2,500 rpm at {{convert|4000|m|ft|abbr=on}}
• Military: {{convert|450|hp|kW|0|abbr=on}} at 2,100 rpm at {{convert|4000|m|ft|abbr=on}}

|specpower=

|compression= 6.4:1

|fuelcon= 225 g/(hp•h) (0.50 lb/(hp•h))

|specfuelcon=

|oilcon= 10 g/(hp•h) (0.022 lb/(hp•h))

|power/weight=

|designer=

|reduction_gear=

|general_other=

|components_other=

|performance_other=

}}

{{aircontent

|see also=

|related=

• Renault 4P
• Renault 6Q

|similar aircraft=

|lists=

• List of aircraft engines

|similar engines=

• Alfa Romeo 122
• Argus As 410
• de Havilland Gipsy Twelve
• Isotta Fraschini Gamma
• Junkers Jumo 210
• Ranger V-770
• Walter Sagitta

}}

{{Commons category}}

{{reflist}}

• {{cite web|author=Ailes Anciennes Le Bourget|url=http://aalebourget.fr/moteur-caudron-cr-714/|title=Le moteur du Caudron CR.714|language=fr|access-date=29 May 2019}}
• {{cite book|last1=Angelucci|first1=Enzo|last2=Matricardi|first2=Paolo|last3=Cosentino|first3=Vincenzo|last4=Tatangelo|first4=Claudio|title=World War II Airplanes|location=Chicago|publisher=Rand McNally|year=1978|isbn=978-0-52888-170-1}}
• {{cite book|last=Angle|first=Glen D.|title=Modern Aircraft Engines|location=New York City|publisher=Aircraft Publications|year=1941|url=https://babel.hathitrust.org/cgi/pt?id=mdp.39015006075827|oclc=658901703}}
• {{cite book|last=Green|first=William|title=War Planes of the Second World War: Volume 8 Bombers and Reconnaissance Aircraft|publisher=MacDonald|location=London|year=1967|oclc=1064406192}}
• {{cite book|last1=Green|first1=William|last2=Swanborough|first2=Gordon|title=The Complete Book of Fighters|year=1994 |publisher=Salamandar|location=London|isbn=978-0-86101-643-3}}
• {{cite book|last1=Grey|first1=C.G.|last2=Bridgman|first2=Leonard|title=Jane's All the World's Aircraft 1938|publisher=Sampson, Low & Martin Company Limited|location=London|year=1938}}
• {{cite book|last=Gunston|first=Bill|title=World Encyclopedia of Aero Engines|location=London|publisher=P. Stephens|year=1998|isbn=978-1-85260-597-1}}
• {{cite web|last=Hartman|first=Gerard|title=Les Moteurs d'Aviation Renault|website=hydroretro.net|url=http://www.hydroretro.net/etudegh/les_moteurs_d_aviation_renault.pdf|date=2015|access-date=29 May 2019|language=Fr}}
• {{cite book|last=Hauet|first=André|title=Les Avions Caudron|volume=2|location=Le Vigen|publisher=Lela Presse|year=2002|isbn=978-2-91401-709-1|language=Fr}}
• {{cite book|last=Wilkinson|first=Paul Howard|title=Aircraft Engines of the World|publisher=Paul H. Wilkinson|location=New York|year=1945|isbn=978-0-91171-024-3|url=https://archive.org/details/in.ernet.dli.2015.205335|access-date=29 May 2019}}

{{Renault aeroengines}}

Category:1930s aircraft piston engines

Category:Inverted V12 aircraft engines

12R

Category:Aircraft air-cooled V piston engines