Renault 12F

{{short description|French V12 aircraft engine series in use during WW1 and the 1920s}}  {{infobox aero engine | name = Renault 12F | image = File: Renault 12Fe MLP 03.jpg | caption = Renault 12Fe engine on display at the Polish Aviation Museum in Kraków |engine_type=Water-cooled V12 aero engine |national_origin =France |manufacturer=Renault |first_run=Late 1915 |major_applications=Breguet 14 |number_built=12Fe: >7,000<br/>Others: ~700 |developed_from=Renault 8G |developed_into= |variants_with_their_own_articles=Renault 12Fe (300 CV) }} The '''Renault 12F''' is a family of liquid-cooled {{cvt|22|L|cuin|abbr=on}} 50 deg V12 aircraft engines that saw widespread use during World War I and the 1920s.

The 12F series was developed from Renault's 8G engines with the two series sharing the same cylinder bore and stoke. 12F series engines were built in Renault's factories in France, Russia and the United Kingdom.

Renault designated early engines in the series by their nominal output of {{cvt|220|hp|kW|abbr=on}}. The engines were progressively improved with the introduction of aluminum pistons allowing for increased power and reduced weight. These progressive improvements eventually lead to the development of a {{cvt|300|hp|kW|abbr=on}} variant which was designated as the '''12Fe''' by the Service Technique de l'Aéronautique (STAe) while being known, and marketed, as the '''300 CV''' (cheval-vapeur) (French: "horsepower”) by Renault.

==Design and development==

In 1914, Renault began building their first water cooled V8 aircraft engines which became known as the 8G series. In 1915, Renault's engineers added two more cylinders to produce a V12 engine with the same bore, stroke and bank angle as the 8Gs. The series became known as the 12F.<ref name=":Pernet">{{Cite journal |last=Bodemer|first=Alfred |date=March 1985 |title=Les Premiers Constructeurs de Moteurs d'Avions Francais|trans-title=The first French aircraft engine manufacturers|url=https://gallica.bnf.fr/ark:/12148/bpt6k53265122/f7.item |journal=Pegase |language=French |issue=37 |page=14}}</ref>{{efn|Renault exhibited the world’s first V12 aircraft engine at the 1911 the Paris airshow. However, this was air-cooled design with a 60-degree bank angle.}}

Engines in the series are V12s with a 50 degree angle between two rows of cylinders each of which has a single overhead camshaft. The crankshaft is carried on four plain bearings with master-and-slave connecting rods allowing corresponding cylinders in each row to be arranged directly opposite each other. Cylinders have a bore of {{cvt|125|mm|in|2}}, a stroke of {{cvt|150|mm|in|2}} and are cast individually. Cylinders are arranged in pairs with one welded liner circulating cooling water around each cylinder pair.<ref name=":TrainingNotes">{{Cite journal |title=Conferences sur les moteurs d'aviation 300 - 450 - 550 hp |url=https://heritage.medialibrary.safran-group.com/Heritage/media/15100 |journal=Handout given to delegates at Renault factories |publisher=Renault |publication-date=December 1921 |issue=Annex A N.E. 21 & N.E. 21A |via=Safran}}</ref><ref name="Angle">{{cite book |last1=Angle |first1=Glenn D. |url=https://archive.org/details/airplaneenginee00anglgoog |title=Airplane Engine Encyclopedia |date=1921 |publisher=The Otterbein Press |location=Dayton, Ohio, USA |pages=417-418}}</ref>

All engines in the series have ignition systems with 100% redundancy. Two spark plugs per cylinder and four magnetos (two per cylinder bank).<ref name=":220Manual">{{Cite journal |title=Moteur d'aviation 220 chevaux |trans-title=Engine manual for 22L 220 hp model |url=https://heritage.medialibrary.safran-group.com/Heritage/media/50374540 |journal=Renault}}</ref><ref name=":300Manual">{{Cite journal |title=Moteur d'aviation 300 chevaux |trans-title=Engine manual for the 22L 300 hp engine |url=https://heritage.medialibrary.safran-group.com/Heritage/media/21847 |journal=Renault |via=Safran}}</ref>

thumb|right|Brochure image of an early 12F variant with radial starter motor

The early 12F engines were often supplied with an aluminium six-cylinder radial pneumatic starter motor which was mounted on the back of the engine.<ref name=":220Manual"/><ref name=":LesMoteurs">{{Cite book |url=https://heritage.medialibrary.safran-group.com/Heritage/media/167295 |title=Les Moteurs D'Aviation Renault |publisher=Drager |via=Safran}}</ref> The pneumatic motor allowed the engine to be restarted mid-flight or on the ground without assistance from ground crew. The starter motor was fed from a pressurised vessel with enough air for ten starts.<ref name=":220Manual"/> The device was not included in later models.<ref name=":TrainingNotes" /><ref name=":300Manual"/><ref name=":LesMoteurs" />

In late 1915 the 220 hp (12Fa) model used cast iron pistons. The engines were progressively improved with the introduction of aluminum pistons allowing for increased power output and reduced weight.<ref name=":TrainingNotes" />

In 1917, the 12Fe model was homologated with a nominal rating of {{cvt|300|hp|kW|0}} (later increased to {{cvt|320|hp|kW|0}}).<ref name=":SYHartmann">{{cite web |last=Hartmann| first=Gerard |date=2005 |title=Les moteurs d’aviation Renault|trans-title=Renault aviation engines|url= https://www.hydroretro.net/etudegh/les_moteurs_d_aviation_renault.pdf|language=FR |access-date=10 December 2023}} </ref> The 12Fe became the standard powerplant for the Breguet 14<ref name=":Windsock">{{Cite book |last=Toelle |first=Alan D |title=Breguet 14 |date=2003 |publisher=Albatros Productions Limited (Windsock Datafile Special) |isbn=1902207610 |pages=52-53 |chapter=Motors and Cowlings}}</ref> and accounted for the vast majority of engines built from the series.<ref name=":SYHartmann" />

12F series engines were exported to the United States<ref name=":Windsock" /> and produced in the United Kingdom.<ref name="Lumsden">{{Cite book |last=Lumsden |first=Alec |title=British Piston Engines and their Aircraft |date=2002 |publisher=Airlife Publishing |isbn=1853102946 |pages=181 |language=en}}</ref>

In Russia, Renault 12F engines were assembled from imported parts by the Russian Renault Society in Petrograd.<ref>{{Cite web |title=Klimov United Engine Corporation. Jsc klimov |url=https://kupichic.ru/en/zhurnal/klimov-obedinennaya-dvigatelestroitelnaya-korporaciya-ao-klimov/ |access-date=31 January 2013 |website=Kupichic.ru}}</ref><ref name=":Kotelnikov">{{Cite book |last=Kotelnikov |first=Vladimir |title=Отечественные авиационные поршневые моторы. 1910–2009 |date=2010 |publisher=Litres |isbn=978-5-91244-017-5 |pages=54-63 |language=Russian |trans-title=Domestic aircraft piston engines. 1910–2009}}</ref> A total of 98 engines were assembled from July 1916 to September 1917. All the engines assembled were early 12F models with cast iron pistons. In 1921 the 12F was re-designated as the '''M-3''' under a new Soviet numbering system which included the '''M-1''' (RBVZ-6) and the '''M-2''' (Le Rhone 9J).<ref name=":Kotelnikov" />

==Variants==

Publications often refer to the 12Fe as the Renault 300 hp with earlier engines in the series referred to as the Renault 220 hp.<ref name=":LesMoteurs" /> Post WW1 the 12Fe engine was marketed as the '''300 CV''' (cheval-vapeur) ''(French: "horsepower”)''.<ref>{{Cite book |last=Hatry |first=Gilbert |url=https://heritage.medialibrary.safran-group.com/Heritage/media/15412 |title=Renault et l'aviation |date=1984 |publisher=Editions JCM |pages=32-41 |language=French |trans-title=Renault and aviation |via=Safran}}</ref>

;12Fa :(1915) Rating of {{cvt|220|hp|kW|0}} at 1300 rpm.<ref name=":SYHartmann" /><ref name=":Windsock" /> Used on the Breguet 14s and Henry Farman HF.35 prototypes.<ref name=":SYHartmann" /> The HF.35 made its first flight in December 1915.<ref>{{Cite book |last=Liron |first=J |title=Les Avions Farman |date=1984 |publisher=Docavia / Editions Lariviere |pages=46 |language=French}}</ref>

;12Fb :(1916) Rating of 250 or 265 hp. Equipped the Paul Schmitt P.S.7<ref name=":SYHartmann" /> and the Breguet 5.<ref>{{Cite book |last=Treadwell |first=Terry |title=British and Allied Aircraft Manufacturers of the First World War |date=2011 |publisher=Amberley |isbn=9781445620091 |location=United Kingdom |chapter=Société des Avions Louis Breguet}}</ref>

;12Fc :Used on early model Bréguet 14s. '''12Fcx''' ({{cvt|250|hp|kW|0}} at 1500 rpm) and '''12Fcy''' ({{cvt|280|hp|kW|0}} at 1600 rpm) sub-variants. In US service 12Fc engines were all rated at {{cvt|300|hp|kW|0}}.<ref name=":Windsock" />

;12Fe {{Main|Renault 12Fe}} :Rated for {{cvt|300|hp|kW|0}} at 1600 rpm. Main production variant in the series and the standard power-plant in the Breguet 14 from late 1917 onwards.<ref name=":Windsock" /> The names 12Fe and 300 CV / hp (cheval-vapeur / horsepower) are used interchangeably in post war technical documentation.<ref name="Breguet14Manual">{{Cite report |date=24 April 1922 |title=Type 14 A2. Model 1921. |journal=Notice technique de l'avion Breguet|url=https://commons.wikimedia.org/wiki/File:Breguet_14_Aircraft_Manual.pdf|publisher=Ministere de la guerre |number=N.C.C.9}}</ref> Some of these engines were fitted with early experimental Rateau turbochargers.<ref name=":Bruce">{{Cite book |last=Bruce |first=J.M |title=The Breguet 14 |last2=Noel |first2=Jean |date=1967 |publisher=Profile Publications |series=157 |location=United Kingdom |asin=B0007JXD5I}}</ref>

; 12Ff :Sometimes used to describe a small number of engines produced with increased bore (128 mm) and stroke (160 mm). Rated for {{cvt|350|hp|kW|0}} at 1,600 rpm. These engines were fitted to a few late production Breguet 14s.<ref name=":Bruce" />

==Applications== ===12Fa, 12Fb and 12Fc=== thumb|right|Breguet 5 powered by a single Renault 12Fb engine (1916) *Breguet 5 *Breguet 14 (prototype and early models) *Henry Farman HF.35 *Henry Farman HF.36 *Nieuport 15 *Paul Schmitt P.S.7 *Curtiss Wanamaker Triplane *Grigorovich M-24 *Sikorsky Ilya Muromets

===12Fe (300 hp)=== thumb|right|Farman F.70 airliner powered by a single Renault 12Fe engine (1922) *Breguet 14 (from late 1917 onwards) *Breguet 16 *Caudron C.91 *Farman F.60 Goliath *Farman F.70 *Georges Levy G.L.40 *Hanriot HD.18 *Latécoère 14 *Latécoère 17 *Lioré et Olivier LeO 8 *Lioré et Olivier LeO H-13 *Paul Schmitt P.S.10 *Potez XV *Voisin X *Airco DH.4 *Royal Aircraft Factory R.E.7 *Short Type 184

===12Ff=== *Breguet 14 (small number of late war examples)

==Specifications (12Fc)== {{pistonspecs |  |type=Water–cooled, upright, 50-degree, V-12 piston engine |ref=''Angle'',<ref name="Angle" /> |bore={{cvt|125|mm|in|2}} |stroke={{cvt|150|mm|in|2}} |displacement={{cvt|22.08|L|cuin|abbr=on}} |length= |diameter= |width= |height= |weight={{cvt|836|lb|kg|0|abbr=on|order=flip}} |valvetrain=SOHC (single overhead camshafts). Two valves per cylinder. |supercharger= |turbocharger= |fuelsystem=Two Zenith duplex carburetors. Heated by water jacket. |fueltype=Gasoline |oilsystem=Wet sump. 2 Gear pumps. One pump circulates oil. The other pump transfers oil from tank to sump. |coolingsystem=Water-cooled. Two centrifugal pumps. |power={{cvt|285|hp|kW|0}} @ 1550 rpm |specpower= |compression=4.6:1 |fuelcon= |specfuelcon={{cvt|0.518|lb/hph|kg/kWh|3|order=flip}} |oilcon={{cvt|0.055|lb/hph|kg/kWh|3|order=flip}} |power/weight={{cvt|0.341|hp/lb|kW/kg|3|abbr=on|order=flip}} |designer= |reduction_gear=None. Direct drive.

|general_other= |components_other='''Rotation:''' Counterclockwise when looking end on at the propeller hub |performance_other=

}}

==See also== {{aircontent  |see also=

|related=

*Renault 8G - A family of V8 engines sharing the same cylinder size and bank angle as the 12F |similar aircraft=

|lists= *List of aircraft engines  |similar engines= *Liberty L-12 *Peugeot 8Aa *Rolls-Royce Eagle *Sunbeam Cossack  }}

== Notes ==

== References == {{reflist}}

==External links== *[https://heritage.medialibrary.safran-group.com/Heritage/media/50374540 Moteur d'aviation 220 chevaux]. Engine manual.

Category: Renault aircraft engines Category:1910s aircraft piston engines Category:V12 aircraft engines Category:Liquid-cooled aircraft piston engines