RAF 3

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RAF 3
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
Developed from RAF 1
Developed into RAF 4

The RAF 3 was 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.[1]

Variants[edit]

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[edit]

Specifications (RAF 3a)[edit]

Data from Lumsden[2]

General characteristics

  • 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)
  • Dry weight: 780 lb (354 kg)

Components

  • Valvetrain: Overhead valve, both valves operated by a single pushrod
  • Cooling system: Liquid-cooled
  • Reduction gear: 0.5:1, left-hand tractor

Performance

See also[edit]

Related development
Comparable engines
Related lists

References[edit]

Notes[edit]

  1. ^ Gunston, 1989, p. 156.
  2. ^ Lumsden 2003, p. 223.

Bibliography[edit]

  • 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.