Wolseley Viper

Viper
Rear view of preserved Wolseley Viper
Type Piston inline aero-engine
Manufacturer Wolseley Motors
First run 1918
Major applications Royal Aircraft Factory S.E.5

The Wolseley Viper is a British-built, high-compression derivative of the Hispano Suiza HS-8 liquid-cooled V-8 engine, built under licence by Wolseley Motors during World War I.

It powered later models of the S.E.5a, SPAD VII and other British or British-built aircraft designed for the Hispano-Suiza.

Variants

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  • Wolseley W.4A Python I (1917)
150 hp (110 kW) – licence produced version of the Hispano-Suiza 8Aa with minor structural changes and the weight increased to 455 lb (206 kg), retained the original's low compression 1.8 in (45 mm) pistons and compression ratio of 4.7:1. Only 100 built.[1][2]
  • Wolseley W.4A Python II
180 hp (130 kW) – high compression version of the Python I with high compression 2 in (50 mm) pistons and compression ratio increased to 5.3:1.[2]
  • Wolseley W.4A* Viper (1918)
200 hp (150 kW) – broadly the equivalent of the Hispano-Suiza 8Ab, compression ratio of 5.3:1 (19 early production engines had a higher compression ratio of 5.6:1), with 200 hp English Hispano propeller hubs.[3]
  • Wolseley W.4B Adder I (1918)
200 hp (150 kW) – modified version of the Hispano-Suiza 8B.[3][4]
  • Wolseley W.4B* Adder II
200 hp (150 kW) – modified and improved version of the Adder I.[3]
  • Wolseley W.4B* Adder III
200 hp (150 kW) – modified and improved version of the Adder II with balanced crankshaft.[3]

Applications

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Surviving engines

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A Wolseley Viper powered Royal Aircraft Factory S.E.5a is owned by, and on display at The Shuttleworth Collection, Old Warden Aerodrome in the UK.[5]

Engines on display

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Specifications (W.4A Viper)

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Data from Gunston[1] and Lumsden[3]

General characteristics

  • Type: 8-cylinder, upright, 90 degree Vee engine
  • Bore: 4.72 in (120 mm)
  • Stroke: 5.12 in (130 mm)
  • Displacement: 716.8 cu in (11.7 L)
  • Length: 46.2 in (1,170 mm)
  • Width: 33.5 in (850 mm)
  • Height: 35.4 in (900 mm)
  • Dry weight: 455 lb (206 kg)

Components

  • Fuel system: Twin Zenith-Duplex carburettors
  • Cooling system: Liquid-cooled
  • Reduction gear: Direct drive, Right-hand tractor

Performance

See also

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Related development

Comparable engines

Related lists

References

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Notes

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  1. ^ a b Gunston (1986), p. 76.
  2. ^ a b Lumsden (1994), pp. 156 & 232.
  3. ^ a b c d e Lumsden (1994), p. 232.
  4. ^ Gunston (1986), p. 171.
  5. ^ The Shuttleworth Collection - SE5a Archived 23 July 2019 at the Wayback Machine www.shuttleworth.org Retrieved: 09 March 2017.

Bibliography

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  • Gunston, Bill (1986). World Encyclopaedia of Aero Engines. Wellingborough: Patrick Stephens Ltd. ISBN 0-85059-717-X.
  • Lumsden, Alec (1994). British Piston Engines and Their Aircraft. Shrewsbury: Airlife Publishing Ltd. ISBN 1-85310-294-6.