Wright R-540 Whirlwind

{{distinguish|Kinner R-540}}  {{infobox aero engine |name = R-540 Whirlwind |image = File:Wright_R540_in_Curtiss_Travel_Air_16E.jpg |caption = Wright R-540 Whirlwind installed in a [[Curtiss-Wright CW-12|Travel Air 16E]] at the [[Historic Aircraft Restoration Museum]] |engine_type=Air-cooled 5-cylinder [[Radial engine|radial piston engine]] |manufacturer=[[Wright Aeronautical Corporation]] |national_origin=United States |major_applications=Various light aircraft |produced=1929-1937 |number_built=around 500 }}

The '''Wright R-540 Whirlwind''' was a series of five-cylinder air-cooled [[radial engine|radial]] [[aircraft engine]]s built by the [[Wright Aeronautical]] division of [[Curtiss-Wright]]. These engines had a [[Engine displacement|displacement]] of 540 in³ (8.85 L) and power ratings of around 165-175 hp (123-130 kW). They were the smallest members of the [[Wright Whirlwind]] engine family.

==Design and development== Wright introduced the J-6 Whirlwind family in 1928 to replace the nine-cylinder [[Wright R-790|R-790]] series. The J-6 family included varieties with five, seven, and nine cylinders. The five-cylinder version was originally known as the '''J-6 Whirlwind Five''', or '''J-6-5''' for short. The U.S. government designated it as the '''R-540'''; Wright later adopted this and dropped the J-6 nomenclature.

Like all the members of the J-6 Whirlwind family, the R-540 had larger cylinders than the R-790. The piston [[stroke (engine)|stroke]] of 5.5 in (14.0 cm) was unchanged, but the cylinder [[bore (engine)|bore]] was expanded to 5.0 in (12.7 cm) from the R-790's bore of 4.5 in (11.4 cm). While the R-790 was [[Naturally-aspirated engine|naturally aspirated]], the R-540, like the other J-6 engines, had a gear-driven [[supercharger]] to boost its power output.

Wright gradually refined the R-540, using suffix letters to indicate successive versions. For example, the R-540A had 165 hp (123 kW), while the R-540E of 1931 had power boosted to 175 hp (130 kW) thanks to an improved [[cylinder head]] design. Wright sometimes named these versions according to their power, e.g. "Whirlwind 165" or "Whirlwind 175".<ref>Curtiss-Wright (1940)</ref>

The engine was built in [[Spain]] as the '''Hispano-Suiza 5Q''' or '''Hispano-Wright 5Q''' without modification apart from the use of Hispano's patented nitriding finishing process.<ref>Lage (2004) pp.152-163</ref>

==Operational history== The R-540 was the smallest, least powerful member of the Whirlwind family and was designed for light aircraft. One of the more popular types to use it was the [[Curtiss Robin]], a light civil utility aircraft. A few were also used in prototype military trainer aircraft that were evaluated by the U.S. Army but not put into production.

The R-540 sold well at first, with over 400 engines being built in 1929.<ref name="wrightprod">{{Citation|title=Summary of Wright Engine Shipments: 1920 to 1963|url=http://enginehistory.org/Wright/WrightProd.pdf|format=PDF|access-date=December 10, 2009|archive-date=March 3, 2016|archive-url=https://web.archive.org/web/20160303223130/http://enginehistory.org/Wright/WrightProd.pdf|url-status=dead}}. Transcribed from Wright Aeronautical documents by Robert J. Neal T; available from the Aircraft Engine Historical Society's [http://enginehistory.org/reference.htm reference page] {{Webarchive|url=https://web.archive.org/web/20100204132400/http://www.enginehistory.org/reference.htm |date=2010-02-04 }}.</ref> However, with the impact of the [[Great Depression]], sales plummeted, and only about 100 further examples were built over the next eight years.<ref name="wrightprod" /> Wright finally ceased production of five-cylinder Whirlwinds in 1937,<ref name="wrightprod" /> concentrating on larger engines and leaving the market for small radials to companies like [[Kinner]] and [[Warner Aircraft Corporation|Warner]].

Since R-540 engines were found solely in light aircraft, they weren't often used for groundbreaking flights. However, there were a couple of noteworthy exceptions which took advantage of the Whirlwind family's reputation for high reliability. In 1935, the brothers [[The Flying Keys|Al and Fred Key]] set a new flight endurance record of 653 hours, 34 minutes in the Curtiss Robin J-1 ''Ole Miss'', flying over [[Meridian, Mississippi]], from June 4 to July 1. Their plane was refueled and resupplied in flight, and they could perform simple engine maintenance by walking out on a small catwalk extending between the cabin and the engine. [[Douglas Corrigan|Douglas "Wrong-Way" Corrigan]]'s famous unauthorized transatlantic flight from [[New York City]] to [[Dublin]], [[Ireland]] on July 17–18, 1938, used a Curtiss Robin with an R-540 built from the parts of two used engines.<ref>Forden (1958) p.84</ref>

==Applications== * [[Curtiss Robin|Curtiss Robin J-1]] * [[Curtiss-Wright CW-12|Curtiss-Wright CW-16]] * [[Parks P-2|Detroit-Parks P-2A]] * [[Emsco B-7]] * [[Fairchild KR-34|Kreider-Reisner Challenger C-4C (Fairchild KR-34C)]] * [[General Aristocrat]] * [[Saro Cloud]] * [[Spartan C3|Spartan C3-165]] * [[Stinson Junior|Stinson Junior SM-2AA and SM-2AB]] * [[Travel Air 2000, 3000 and 4000|Travel Air E-4000]] * [[Waco 10|Waco BSO]]

==Engines on display== Wright R-540 engines on display are uncommon, but there is one at the [[Strategic Air and Space Museum]] (formerly the Strategic Air Command Museum) near [[Ashland, Nebraska]].<ref>{{Citation|title=Aircraft Engines|url=http://passion-aviation.qc.ca/engines.htm|access-date=2008-09-11|archive-date=2017-07-28|archive-url=https://web.archive.org/web/20170728192438/http://www.passion-aviation.qc.ca/engines.htm|url-status=dead}}. This personal collection of museum aircraft engine photos includes a photo of a Wright R-540 under the SAC Museum section. (The page mislabels it as a "Wright R-540 J-5"—there never was a five-cylinder version of the J-5.)</ref> Another is on display at the Shannon Air Museum in [[Fredericksburg, Virginia]].

==Specifications (R-540E)== {{pistonspecs|   |ref=[[FAA]] [[type certificate]] data sheet for the R-540E;<ref>FAA, ATC 23 data sheet</ref> dimensions from Curtiss-Wright (1983). |type=5-cylinder supercharged air-cooled radial piston engine |bore=5.0 in (127 mm) |stroke=5.5 in (140 mm) |displacement=540 cu in (8.85 L) |length=41.1 in (104.4 cm) |diameter=45.0 in (114.3 cm) |width= |height= |weight=420 lb (191 kg) |valvetrain=2 [[4-stroke cycle engine valves|valves]] per cylinder, [[pushrod]]-actuated |supercharger=gear-driven, 7.05:1 [[impeller]] [[gear ratio]] |turbocharger= |fuelsystem= |fueltype=65 [[Octane rating|octane]] |oilsystem= |coolingsystem= |power=175 hp (130 kW) at 2,000 RPM at sea level |specpower=0.324 hp/cu-in (14.7 kW/L) |compression=5.1:1 |fuelcon= |specfuelcon= |oilcon= |power/weight=0.417 hp/lb (0.685 kW/kg) |designer= |reduction_gear=Direct drive |general_other= |components_other= |performance_other= }}

==See also== {{aircontent |see also= * [[Wright Whirlwind]] |related= *[[Wright R-790|Wright J-5/R-790]] *[[Wright R-760|Wright J-6-7/R-760]] *[[Wright R-975|Wright J-6-9/R-975]] |similar aircraft= |lists= * [[List of aircraft engines]] |similar engines= *[[Armstrong Siddeley Mongoose]] *[[Kinner R-5]] *[[Shvetsov M-11]] }}

==References== {{Commons category}}

===Notes=== {{Reflist}}

===Bibliography=== {{refbegin}} *{{Citation|title=Wright Engines - Past and Present|url=http://enginehistory.org/Wright/CWthrough1940.pdf|format=PDF|last=Curtiss-Wright|author-link=Curtiss-Wright|year=1940|pages=12–13|access-date=December 10, 2009|archive-date=February 15, 2010|archive-url=https://web.archive.org/web/20100215023451/http://enginehistory.org/Wright/CWthrough1940.pdf|url-status=dead}}. Available from the Aircraft Engine Historical Society's [http://enginehistory.org/reference.htm reference page] {{Webarchive|url=https://web.archive.org/web/20100204132400/http://www.enginehistory.org/reference.htm |date=2010-02-04 }}. *{{Citation | title= Whatever Became of the Curtis Robin|last=Forden|first=Lesley|magazine=Flying|volume=62|number=4|year=1958|pages=54–84}} *{{Citation |title= Hispano Suiza in Aeronautics|last=Lage|first=Manual| year=2004|publisher=SAE International|location=Warrendale, USA |isbn=0-7680-0997-9 }} *{{Citation|title=Historical Engine Summary (Beginning 1930)|url=http://enginehistory.org/Wright/CWafter1930_2.pdf|format=PDF|last=Curtiss-Wright|author-link=Curtiss-Wright|year=1983|page=1|access-date=December 10, 2009|archive-date=October 31, 2010|archive-url=https://web.archive.org/web/20101031225258/http://enginehistory.org/Wright/CWafter1930_2.pdf|url-status=dead}}. Available from the Aircraft Engine Historical Society's [http://enginehistory.org/reference.htm reference page] {{Webarchive|url=https://web.archive.org/web/20100204132400/http://www.enginehistory.org/reference.htm |date=2010-02-04 }}. *{{Citation|title=Approved Type Certificate No. 23 (ATC 23) data sheet|url=http://rgl.faa.gov/Regulatory_and_Guidance_Library%5CrgMakeModel.nsf/0/DC281F1481D67B3A8525670E006674D6?OpenDocument|last=Federal Aviation Administration|author-link=Federal Aviation Administration|access-date=December 10, 2009}}. Available from the FAA's [http://rgl.faa.gov Regulatory and Guidance Library] {{Webarchive|url=https://web.archive.org/web/20161112071304/http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/E68A34E7A9B5DBF1862572C0006DB044?OpenDocument |date=2016-11-12 }}. *{{Citation|title=Model Designations of USAF Aircraft Engines: Section I, Reciprocating Engine Characteristics|url=http://enginehistory.org/ModDesig/SecI.pdf|format=PDF|last=USAF Air Materiel Command|date=January 1, 1950|page=8|access-date=December 10, 2009}}. Available from the Aircraft Engine Historical Society's [http://enginehistory.org/reference.htm reference page] {{Webarchive|url=https://web.archive.org/web/20100204132400/http://www.enginehistory.org/reference.htm |date=2010-02-04 }}. {{refend}}

[[Category:1920s aircraft piston engines]] [[Category:Aircraft air-cooled radial piston engines]] [[Category:Wright aircraft engines|R-540]]