{{Use dmy dates|date=December 2016}} {{Use British English|date=December 2016}} <!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. --> {{infobox aero engine |name=Viper |image= WolseleyViper.JPG |caption=Rear view of preserved Wolseley Viper |engine_type=[[Reciprocating engine|Piston]] [[Inline engine (aviation)|inline]] [[Aircraft engine|aero-engine]] |manufacturer=[[Wolseley Motors]] |first_run=1918 |major_applications=[[Royal Aircraft Factory S.E.5]] |number_built = |developed_from = |developed_into = |variants_with_their_own_articles = }}
The '''Wolseley Viper''' is a British-built, high-compression derivative of the [[Hispano-Suiza 8|Hispano Suiza HS-8]] liquid-cooled [[V8 engine|V8]] engine, built under licence by [[Wolseley Motors]] during [[World War I]].
It powered later models of the [[Royal Aircraft Factory S.E.5|S.E.5a]], [[SPAD S.VII|SPAD VII]] and other British or British-built aircraft designed for the Hispano-Suiza.
==Variants== * '''Wolseley W.4A Python I''' (1917){{pb}}{{cvt|150|hp|kW}} – licence produced version of the [[Hispano-Suiza 8|Hispano-Suiza 8Aa]] with minor structural changes and the weight increased to {{cvt|455|lb|kg}}, retained the original's low compression {{cvt|45|mm|in|order=flip}} pistons and compression ratio of 4.7:1. Only 100 built.{{sfnp|Gunston|1986|p=76}}{{sfnp|Lumsden|1994|pp=156 & 232}} * '''Wolseley W.4A Python II'''{{pb}}{{cvt|180|hp|kW}} – high compression version of the Python I with high compression {{cvt|50|mm|in|0|order=flip}} pistons and compression ratio increased to 5.3:1.{{sfnp|Lumsden|1994|pp=156 & 232}} * '''Wolseley W.4A* Viper''' (1918){{pb}}{{cvt|200|hp|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.{{sfnp|Lumsden|1994|p=232}} * '''Wolseley W.4B Adder I''' (1918){{pb}}{{cvt|200|hp|kW}} – modified version of the Hispano-Suiza 8B.{{sfnp|Lumsden|1994|p=232}}{{sfnp|Gunston|1986|p=171}} * '''Wolseley W.4B* Adder II'''{{pb}}{{cvt|200|hp|kW}} – modified and improved version of the Adder I.{{sfnp|Lumsden|1994|p=232}} * '''Wolseley W.4B* Adder III'''{{pb}}{{cvt|200|hp|kW}} – modified and improved version of the Adder II with balanced crankshaft.{{sfnp|Lumsden|1994|p=232}}
==Applications== *[[Airco DH.9]] *[[Avro 552]] *[[Bristol M.R.1]] *[[Bristol Tourer]] *[[Cierva C.8]] *[[Martinsyde Buzzard|Martinsyde F.6]] *[[Royal Aircraft Factory S.E.5a]] *[[Sopwith Antelope]] *[[Sopwith Cuckoo]]
==Surviving engines== 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.<ref>[http://www.shuttleworth.org/collection/se5a/ The Shuttleworth Collection - SE5a] {{Webarchive|url=https://web.archive.org/web/20190723153201/http://www.shuttleworth.org/collection/se5a/ |date=23 July 2019 }} www.shuttleworth.org Retrieved: 09 March 2017.</ref>
==Engines on display== *A preserved Wolseley Viper is on public display at the [[Science Museum, London]]. *A preserved Wolseley Viper is on public display at the [[Museo Nacional de Aeronáutica de Argentina]]
==Specifications (W.4A Viper)== {{pistonspecs| <!-- If you do not understand how to use this template, please ask at [[Wikipedia talk:WikiProject Aircraft]] --> <!-- Please include units where appropriate (main comes first, alt in parentheses). If data are missing, leave the parameter blank (do not delete it). For additional lines, end your alt units with )</li> and start a new, fully-formatted line with <li> --> |ref=[[Bill Gunston|Gunston]]{{sfnp|Gunston|1986|p=76}} and Lumsden{{sfnp|Lumsden|1994|p=232}} |type=Upright, 90 degree V8 |bore={{cvt|4.72|in|mm}} |stroke={{cvt|5.12|in|mm}} |displacement={{cvt|716.8|cuin|L|1}} |length={{cvt|46.2|in|mm}} |diameter= |width={{cvt|33.5|in|mm}} |height={{cvt|35.4|in|mm}} |weight={{cvt|455|lb}} |valvetrain= |supercharger= |turbocharger= |fuelsystem=Twin Zenith-Duplex carburettors |fueltype= |oilsystem= |coolingsystem=Liquid-cooled |power={{cvt|200|–|210|hp|kW}} |specpower= |compression=5.3:1 |fuelcon= |specfuelcon= |oilcon= |power/weight= |designer= |reduction_gear=Direct drive, Right-hand tractor |general_other= |components_other= |performance_other= }}
==See also== {{aircontent <!-- other related articles that have not already linked: --> |see also=
<!-- designs which were developed into or from this aircraft: --> |related= *[[Hispano-Suiza 8]] <!-- aircraft that are of similar role, era, and capability as this design: --> |similar aircraft=
<!-- relevant lists that this aircraft appears in: --> |lists= *[[List of aircraft engines]] <!-- For aircraft engine articles. Engines that are of similar to this design: --> |similar engines= *[[Peugeot 8Aa]] *[[Sunbeam Arab]] <!-- See [[WP:Air/PC]] for more explanation of these fields. --> }}
==References== {{Commons category}}
===Notes=== {{reflist}}
===Bibliography=== {{refbegin}} * {{cite book |last=Gunston |first=Bill |author-link=Bill Gunston |date=1986 |title=World Encyclopaedia of Aero Engines |location=[[Wellingborough]] |publisher=Patrick Stephens Ltd |isbn=0-85059-717-X}} * {{cite book |last=Lumsden |first=Alec |date=1994 |title=British Piston Engines and Their Aircraft |location=[[Shrewsbury]] |publisher=Airlife Publishing Ltd |isbn=1-85310-294-6}} {{refend}}
{{Wolseley aeroengines}}
[[Category:Wolseley aircraft engines|Viper]] [[Category:1910s aircraft piston engines]] [[Category:V8 engines]] [[Category:Liquid-cooled aircraft piston engines]]