# Wolseley Viper > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Wolseley_Viper > Markdown URL: https://mediated.wiki/source/Wolseley_Viper.md > Source: https://en.wikipedia.org/wiki/Wolseley_Viper > Source revision: 1351843977 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) 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](/source/Hispano-Suiza_8) liquid-cooled [V8](/source/V8_engine) engine, built under licence by [Wolseley Motors](/source/Wolseley_Motors) during [World War I](/source/World_War_I). It powered later models of the [S.E.5a](/source/Royal_Aircraft_Factory_S.E.5), [SPAD VII](/source/SPAD_S.VII) and other British or British-built aircraft designed for the Hispano-Suiza. ## Variants - **Wolseley W.4A Python I** (1917) 150 hp (110 kW) – licence produced version of the [Hispano-Suiza 8Aa](/source/Hispano-Suiza_8) 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 - [Airco DH.9](/source/Airco_DH.9) - [Avro 552](/source/Avro_552) - [Bristol M.R.1](/source/Bristol_M.R.1) - [Bristol Tourer](/source/Bristol_Tourer) - [Cierva C.8](/source/Cierva_C.8) - [Martinsyde F.6](/source/Martinsyde_Buzzard) - [Royal Aircraft Factory S.E.5a](/source/Royal_Aircraft_Factory_S.E.5a) - [Sopwith Antelope](/source/Sopwith_Antelope) - [Sopwith Cuckoo](/source/Sopwith_Cuckoo) ## Surviving engines A Wolseley Viper powered [Royal Aircraft Factory S.E.5a](/source/Royal_Aircraft_Factory_S.E.5a) is owned by, and on display at [The Shuttleworth Collection](/source/The_Shuttleworth_Collection), [Old Warden Aerodrome](/source/Old_Warden_Aerodrome) in the UK.[5] ## Engines on display - A preserved Wolseley Viper is on public display at the [Science Museum, London](/source/Science_Museum%2C_London). - A preserved Wolseley Viper is on public display at the [Museo Nacional de Aeronáutica de Argentina](/source/Museo_Nacional_de_Aeron%C3%A1utica_de_Argentina) ## Specifications (W.4A Viper) *Data from* [Gunston](/source/Bill_Gunston)[1] and Lumsden[3] ### General characteristics - **Type:** Upright, 90 degree V8 - **[Bore](/source/Bore_(engine)):** 4.72 in (120 mm) - **[Stroke](/source/Stroke_(engine)):** 5.12 in (130 mm) - **[Displacement](/source/Engine_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](/source/Dry_weight):** 455 lb (206 kg) ### Components - **Fuel system:** Twin Zenith-Duplex carburettors - **Cooling system:** Liquid-cooled - **[Reduction gear](/source/Propeller_speed_reduction_unit):** Direct drive, Right-hand tractor ### Performance - **Power output:** 200–210 hp (150–160 kW) - **[Compression ratio](/source/Compression_ratio):** 5.3:1 ## See also **Related development** - [Hispano-Suiza 8](/source/Hispano-Suiza_8) **Comparable engines** - [Peugeot 8Aa](/source/Peugeot_8Aa) - [Sunbeam Arab](/source/Sunbeam_Arab) **Related lists** - [List of aircraft engines](/source/List_of_aircraft_engines) ## References Wikimedia Commons has media related to [Wolseley Viper](https://commons.wikimedia.org/wiki/Category:Wolseley_Viper). ### Notes 1. ^ [***a***](#cite_ref-FOOTNOTEGunston198676_1-0) [***b***](#cite_ref-FOOTNOTEGunston198676_1-1) [Gunston (1986)](#CITEREFGunston1986), p. 76. 1. ^ [***a***](#cite_ref-FOOTNOTELumsden1994156_&_232_2-0) [***b***](#cite_ref-FOOTNOTELumsden1994156_&_232_2-1) [Lumsden (1994)](#CITEREFLumsden1994), pp. 156 & 232. 1. ^ [***a***](#cite_ref-FOOTNOTELumsden1994232_3-0) [***b***](#cite_ref-FOOTNOTELumsden1994232_3-1) [***c***](#cite_ref-FOOTNOTELumsden1994232_3-2) [***d***](#cite_ref-FOOTNOTELumsden1994232_3-3) [***e***](#cite_ref-FOOTNOTELumsden1994232_3-4) [Lumsden (1994)](#CITEREFLumsden1994), p. 232. 1. **[^](#cite_ref-FOOTNOTEGunston1986171_4-0)** [Gunston (1986)](#CITEREFGunston1986), p. 171. 1. **[^](#cite_ref-5)** [The Shuttleworth Collection - SE5a](http://www.shuttleworth.org/collection/se5a/) [Archived](https://web.archive.org/web/20190723153201/http://www.shuttleworth.org/collection/se5a/) 23 July 2019 at the [Wayback Machine](/source/Wayback_Machine) www.shuttleworth.org Retrieved: 09 March 2017. ### Bibliography - [Gunston, Bill](/source/Bill_Gunston) (1986). *World Encyclopaedia of Aero Engines*. [Wellingborough](/source/Wellingborough): Patrick Stephens Ltd. [ISBN](/source/ISBN_(identifier)) [0-85059-717-X](https://en.wikipedia.org/wiki/Special:BookSources/0-85059-717-X). - Lumsden, Alec (1994). *British Piston Engines and Their Aircraft*. [Shrewsbury](/source/Shrewsbury): Airlife Publishing Ltd. [ISBN](/source/ISBN_(identifier)) [1-85310-294-6](https://en.wikipedia.org/wiki/Special:BookSources/1-85310-294-6). v t e Wolseley aero engines V8 engines (1910–1918) 60 hp 80 hp 160 hp Adder Python Viper Radial engines (1931–1935) AR.7 (Aquarius) AR.9 (Aries, Leo, Libra, Scorpio) --- Adapted from the Wikipedia article [Wolseley Viper](https://en.wikipedia.org/wiki/Wolseley_Viper) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Wolseley_Viper?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.