RAF 3
{{Short description|British aircraft engine}}
| {{Infobox Aircraft Begin
|name=RAF 3 |image=RAF 3a Napier MLP 04.jpg |caption=RAF 3a on display at the Polish Aviation Museum }}{{Infobox Aircraft Engine |type=Piston inline aero engine |national origin=United Kingdom |manufacturer=Royal Aircraft Factory |first run=September 1914 |major applications=Royal Aircraft Factory R.E.7 |number built = 289 |program cost = |unit cost = |developed from = RAF 1 |developed into = RAF 4 |variants with their own articles = }} |
The RAF 3 is a British liquid-cooled, V-12 engine developed for aircraft use during World War I. Based on the eight–cylinder RAF 1 it was designed by the Royal Aircraft Factory but produced by the two British companies of Armstrong Whitworth and Napier & Son. The RAF 7 was a high compression version of the same engine.Gunston, 1989, p. 156.
Variants
;RAF 3
:1914 - Prototype engine, 200 horsepower (150 kW).
;RAF 3a
:1914 - Main production variant, increased bore, 260 horsepower (194 kW). 29 built by Armstrong Whitworth, 260 built by Napier & Son.
;RAF 7
:300 horsepower (224 kW) high compression version with high-lift camshafts.
Applications
Specifications (RAF 3a)
{{pistonspecs|
|ref=LumsdenLumsden 2003, p. 223.
|type=12-cylinder, upright, 60-degree Vee engine
|bore=4.5 in (114.3 mm)
|stroke=5.5 in (140 mm)
|displacement=1,049.4 cu in (17.24 L)
|length=
|diameter=
|width=
|height=
|weight=780 lb (354 kg)
|valvetrain=Overhead valve, both valves operated by a single pushrod
|supercharger=
|turbocharger=
|fuelsystem=
|fueltype=
|oilsystem=
|coolingsystem=Liquid-cooled
|power=260 hp (194 kW) at 1,750 rpm (takeoff power)
|specpower=0.25 hp/cu in (11.25 kW/L)
|compression=5.3:1
|fuelcon=
|specfuelcon=
|oilcon=
|power/weight=0.33 hp/lb (0.54 kW/kg)
|designer=
|reduction_gear=0.5:1, left-hand tractor
|general_other=
|components_other=
|performance_other=
}}
See also
{{aircontent
|see also=
|related=
|lists=
|similar engines=
}}
References
=Notes=
{{reflist}}
=Bibliography=
{{Commons category}}
{{refbegin}}
- Gunston, Bill. World Encyclopaedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. {{ISBN|1-85260-163-9}}
- Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. {{ISBN|1-85310-294-6}}.
{{refend}}
{{Royal Aircraft Factory aeroengines}}