View source for Rolls-Royce R

{{short description|1929 British aero engine}}
{{Use dmy dates|date=August 2021}}
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{|{{Infobox aircraft begin
 |name=Rolls-Royce R
 |image=RollsRoyceR(ScienceMuseum).JPG
 |caption=Rolls-Royce R (''R27'') on display at the [[Science Museum (London)|London Science Museum]]. The rectangular red objects are the exhaust ports blanking plates which would be replaced by the exhaust stubs/pipes when fitted to an aircraft or other vehicle|alt=A front left view of a large black-painted aircraft piston engine. The engine is backlit by a window. 
}}{{Infobox aircraft engine
 |type=[[Reciprocating engine|Piston]] [[V12 engine|V-12]] [[Aircraft engine|aero engine]]
 |manufacturer=[[Rolls-Royce Limited]]
 |designer=[[Arthur Rowledge]]
 |first run=7 April 1929
 |major applications=[[Supermarine S.6]]<br>[[Supermarine S.6B]]<br>''[[Blue Bird K4]]''
 |number built = 19 
 |program cost = 
 |unit cost =
 |developed from = [[Rolls-Royce Buzzard]]
 |developed into = 
 |variants with their own articles =
}}
|}

The '''Rolls-Royce R''' is a British [[Aircraft engine|aero engine]] that was designed and built specifically for [[air racing]] purposes by [[Rolls-Royce Limited]]. Nineteen R engines were assembled in a limited production run between 1929 and 1931. Developed from the [[Rolls-Royce Buzzard]], it was a 37-litre (2,240&nbsp;cu in) [[Engine displacement|capacity]], [[Supercharger|supercharged]] [[V12 engine|V-12]] capable of producing just under {{convert|2,800|hp|kW|abbr=off}}, and weighed {{convert|1,640|lb|kg}}. Intensive factory testing revealed mechanical failures which were remedied by redesigning the components, greatly improving reliability.

The R was used with great success in the [[Schneider Trophy]] [[seaplane]] competitions held in England in 1929 and 1931. Shortly after the 1931 competition, an R engine using a special fuel blend powered the winning [[Supermarine S.6B]] aircraft to a new [[Flight airspeed record|airspeed record]] of over {{convert|400|mph|km/h}}. Continuing through the 1930s, both new and used R engines were used to achieve various [[land speed record|land]] and [[water speed record]]s by such racing personalities as [[Henry Segrave|Sir Henry Segrave]], [[Malcolm Campbell|Sir Malcolm Campbell]] and his son [[Donald Campbell|Donald]], the last record being set in 1939. A final R-powered water speed record attempt by Donald Campbell in 1951 was unsuccessful.

The experience gained by Rolls-Royce and Supermarine designers from the R engine was invaluable in the subsequent development of the [[Rolls-Royce Merlin]] engine and the [[Supermarine Spitfire|Spitfire]]. A de-rated R engine, known as the '''''Griffon''''', was tested in 1933, but it was not directly related to the production [[Rolls-Royce Griffon]] of 1939, of the same exact bore/stroke and resultant displacement figures as the "R" design. Three examples of the R engine are on public display in British museums as of 2014.
{{TOC limit|3}}

==Design and development==

===Origin===
Rolls-Royce realised that the [[Napier Lion]] engine used in the 1927 [[Supermarine S.5]] Schneider Trophy winner had reached the peak of its development, and that for Britain's entrant in the next race to be competitive a new, more powerful engine design was required. The first configuration drawing of the "Racing H" engine, based on the [[Rolls-Royce Buzzard|Buzzard]],{{#tag:ref|The Buzzard was itself a 6:5 scaled-up [[Rolls-Royce Kestrel]].|group=nb}} was sent to [[R. J. Mitchell]] of [[Supermarine]] on 3 July 1928, allowing Mitchell to start design of the new [[Supermarine S.6|S.6]] Schneider Trophy seaplane.<ref>Eves 2001, p. 174.</ref> Shortly after this the engine's name was changed to R for "Racing".<ref name="Holter 2002, p. 35">Holter 2002, p. 35.</ref> An official British Government contract to proceed with the project was not awarded until February 1929, leaving Rolls-Royce six months to develop the engine before the planned Schneider Trophy competition of that year.<ref>Lumsden 2004, p. 168.</ref><ref name="Lumsden199"/>{{#tag:ref|Cost: £5,800, the price paid by Malcolm Campbell to Rolls-Royce for ''R37'' in 1933.<ref name="Holter42">Holter 2002, p. 42.</ref>|group=nb}}

===Description===
The R was a physically imposing engine designed by a team led by [[Ernest Hives, 1st Baron Hives|Ernest Hives]] and including [[Cyril Lovesey]], [[Arthur Rowledge]] and [[Henry Royce]]. The R shared the Buzzard's [[Bore (engine)|bore]], [[Stroke (engine)|stroke]] and capacity, and used the same 60-[[Degree (angle)|degree]] V-12 layout. A new single-stage, double-sided [[supercharger]] impeller was designed along with revised [[Cylinder (engine)|cylinders]] and strengthened [[connecting rod]]s.<ref name="Eves225">Eves 2001, p. 225.</ref> The wet-liner [[cylinder block]]s,{{#tag:ref|"Wet liners" are formed separately from the main cylinder block casting so that liquid coolant is free to flow around their outsides. As a result, wet-lined cylinders have better cooling and a more even temperature distribution.|group=nb}} [[crankcase]] and [[Propeller speed reduction unit|propeller reduction gear]] castings were produced from "[[Hiduminium|R.R 50]]" [[aluminium alloy]];<ref name="Eves226"/> and because of the short life expectancy of these engines, forged aluminium was used to replace bronze and steel in many parts.<ref name="Flight990">[Staff author] 2 October 1931. "[http://www.flightglobal.com/pdfarchive/view/1931/1931%20-%201060.html The Rolls-Royce Racing Engines]" ''Flight'', p. 990. www.flightglobal.com. Retrieved: 14 November 2009.</ref> 
[[File:Rolls-Royce Merlin Cylinders.JPG|thumb|left|alt=Sectioned view of a piston engine|Sectioned view of a [[Rolls-Royce Merlin]] which featured wet-liner cylinders and lower oil scraper rings, both originally developed for the R engine]]
To make the R as compact as possible, several design modifications were made in comparison to the Buzzard: the propeller reduction gear housing was reshaped, and the [[Overhead camshaft|camshaft]] and [[Rocker arm|rocker]] covers were modified to [[Aircraft fairing|fair]] into the shape of the aircraft's nose, the air intake was positioned in the vee of the engine (which also helped to avoid the ingress of spray), and beneath the engine the [[Automobile accessory power|auxiliaries]] were raised a little to reduce the depth of the [[fuselage]].<ref name="Flight989">"[Staff author] 2 October 1931. "[http://www.flightglobal.com/pdfarchive/view/1931/1931%20-%201059.html The Rolls-Royce Racing Engines]" ''Flight'', p. 989. www.flightglobal.com. Retrieved: 14 November 2009.</ref> The engine's length was minimised by not staggering its cylinder banks fore and aft, which meant that the connecting rods from opposing cylinders had to share a short [[crankshaft]] bearing journal known as the "[[Crankpin|big end]]". This was initially achieved by fitting one connecting rod inside the other at the lower end in a blade and fork arrangement; however, after cracking of the connecting rods was found during testing in 1931, the rod design was changed to an [[Connecting rod#Compound rods|articulated type]].<ref name="Eves226"/>

The introduction of articulated connecting rods was regarded as a "nuisance" by [[Arthur Rubbra]], a Rolls-Royce engine designer, as there were inherent problems with the arrangement. The complicated geometry meant that a pair of rods had different effective lengths, giving a longer [[Stroke (engine)|stroke]] on the articulated side; consequently the cylinder liners on that side had to be lengthened to prevent the [[Piston ring|oil scraper ring]] from running out of the cylinder skirt. Articulated rods were used in the [[Rolls-Royce Goshawk|Goshawk]] engine, but were not embodied in the later [[Rolls-Royce Merlin]], for which Arthur Rowledge had designed a revised blade and fork system.<ref>Rubbra 1990, p. 60.</ref>

Later production R engines featured [[sodium|sodium-filled]] [[Poppet valve|exhaust valve]] stems for improved cooling, while additional modifications included a redesigned lower crankcase casting and the introduction of an oil scraper ring below the piston [[gudgeon pin]]; a measure that was carried over to the Merlin engine. A [[Crankshaft#Engine balance|balanced crankshaft]] was introduced in May 1931, and the [[compression ratio]] on the "sprint" engines prepared for that year was raised from 6:1 to 7:1.<ref name="Eves229"/>

The [[ignition system]] consisted of two rear-mounted, crankshaft-driven [[ignition magneto|magneto]]s, each supplying one of a pair of [[spark plugs]] fitted to each cylinder. This is common practise for aero engines, as it ensures continued operation in the case of a single magneto failure, and has the advantage of more efficient [[combustion]] over a single spark plug application.<ref>Gunston 2006, p. 60.</ref>

===Cooling===
[[Internal combustion engine cooling|Cooling]] this large engine whilst minimising aerodynamic [[Drag (physics)|drag]] posed new challenges for both the Rolls-Royce and Supermarine design teams. Traditional cooling methods using honeycomb-type [[radiator]]s were known to cause high drag in flight; consequently it was decided to use the surface skins of the S.6 wings and [[Floats (nautical)|floats]] as heat exchangers, employing a double-skinned structure through which the coolant could circulate. Engine oil was cooled in a similar manner using channels in the [[fuselage]] and [[empennage]] skins. The S.6 was described at the time as a "flying radiator", and it had been estimated that this coolant system dissipated the equivalent of {{convert|1,000|hp|kW|abbr=on}} of [[heat]] in flight. However, even with this system in use, engine overheating was noted during the race flights, requiring the pilots to reduce the throttle setting to maintain a safe [[operating temperature]].<ref>[Staff author] 16 July 1942. "[http://www.flightglobal.com/pdfarchive/view/1942/1942%20-%201477.html ''Voices From The Past'', Recorded talks by Schneider Trophy Contest designers and the winning pilot]" ''Flight'', p. 61. www.flightglobal.com. Retrieved 21 October 2009.</ref>

A not-so-obvious cooling measure was the deliberate use of a [[Air-fuel ratio|rich fuel mixture]], which accounts for the frequent reports of black smoke seen issuing from the engine exhaust stubs.<ref>Eves 2001, p. 208.</ref> Although this robbed the engine of some power, it increased reliability and reduced the possibility of [[detonation]] in the cylinders.<ref name="Eves210"/> <!-- Could use FAA powerplant notes here  --><!-- Methanol as coolant ?-->

===Supercharger and fuel===
[[File:RollsRoyceRSupercharger.JPG|thumb|right|alt=A rear view of an aircraft piston engine shows details of the induction system.|Supercharger detail of the Rolls-Royce R]]
The keys to the R engine's high [[power-to-weight ratio]] were its [[supercharger]] design, ability to run at high revolutions due to its structural strength, and the special blends of fuel used. The double-sided supercharger impeller was a new development for Rolls-Royce: running at a ratio of almost 8:1, it could supply intake air at up to 18&nbsp;[[pounds per square inch]] (psi) (1.24&nbsp;[[Bar (unit)|bar]]) above [[atmospheric pressure]], a figure known as "boost" and commonly abbreviated as "+''[[Variable (mathematics)|x]]''&nbsp;lb".<ref name="Holter175">Holter 2002, p. 175.</ref> By comparison the maximum boost of the earlier [[Rolls-Royce Kestrel]] design was +6&nbsp;lb (0.4&nbsp;bar), this figure not being achieved until 1934.<ref>Lumsden 2003, p. 195.</ref> The high boost pressures initially caused the [[spark plugs]] to fail on test, and eventually the [[Lodge Plugs Ltd|Lodge]] type X170 plug was chosen as it proved to be extremely reliable.<ref name="Flight990"/><ref>Eves 2001, pp. 230–231.</ref>

The development of special fuel was attributed to the work of [[Francis Rodwell Banks|"Rod" Banks]], an engineer who specialised in fuels and engine development. After using neat [[benzole]] for early ground test runs, a mixture of 11% [[Avgas|aviation petrol]] and 89% benzole plus 5&nbsp;[[cubic centimetre]]s (cc) of [[tetra-ethyl lead]] per [[Imperial units#Volume|Imperial gallon]] (4.5&nbsp;L) was tried. This blend of fuel was used to win the 1929 Schneider Trophy race, and continued to be used until June 1931.<ref name="Eves230">Eves 2001, p. 230.</ref> It was discovered that adding 10% [[methanol]] to this mixture resulted in a {{convert|20|hp|kW|abbr=on}} increase, with the further advantage of reduced fuel weight&nbsp;– particularly important for aircraft use&nbsp;– due to its lowered [[Relative density|specific gravity]]. For the 1931 airspeed record attempt [[acetone]] was added to prevent intermittent misfiring; the composition of this final blend was 30% benzole, 60% methanol, and 10% acetone, plus 4.2&nbsp;cc of tetra-ethyl lead per gallon.<ref name="Eves230"/>

On an early test run the R engine produced {{convert|1,400|hp|kW|abbr=on}} and was noted to [[Idle speed|idle]] happily at 450&nbsp;[[revolutions per minute]] (rpm). With increased boost ratings and fuel developed by Banks, the R engine ultimately developed {{convert|2,530|hp|kW|abbr=on}} at 3,200&nbsp;rpm; well over double the maximum power output of the [[Rolls-Royce Buzzard|Buzzard]].<ref>Lumsden 2003, p. 198.</ref>{{#tag:ref|Maximum power output of the Rolls-Royce Buzzard was {{convert|920|hp|kW|abbr=on}} at 2,300&nbsp;rpm.|group=nb}} The engine was further tested and cleared for limited sprint racing at {{convert|2,783|hp|kW|abbr=on}} at 3,400&nbsp;rpm and +21&nbsp;lb (1.45&nbsp;bar) of boost,<ref>Gunston 1989, p. 139.</ref> but this capability was not used due to concerns with the S.6B's [[airframe]] not being able to withstand the power, and the inability of the aircraft to lift the extra fuel required to meet the increased consumption.<ref name="Lumsden199">Lumsden 2003, p. 199.</ref>

===Testing===

====Ground testing====
The first run of engine ''R1'' took place at Rolls-Royce's [[Osmaston, Derby|Derby]] factory on 7 April 1929 with ''R7'' running the next day.<ref name="Holter 2002, p. 35"/><ref name="Eves226"/> Many mechanical failures were experienced during bench testing including burnt valves, connecting rod breakages and [[main bearing]] seizures,<ref name="Holter38">Holter 2002, p. 38.</ref> while considerably more trouble than expected occurred with valve springs; at one time two or three would be found broken after a 10-minute run,<ref name="Flight990"/> but the continual redesigning and testing of components reduced all these problems. Unknown to Royce himself, the engineers had also fitted "[[Wellworthy Piston Rings Limited|Wellworthy]]"{{#tag:ref|Wellworthy was the trade name of a British piston and piston ring manufacturer.|group=nb}} pistons that were better able to withstand the 13&nbsp;[[ton]]s "pressure"{{#tag:ref|The source is unclear as to the exact meaning of this statement – it may refer to the total force exerted on the piston, or the force per unit area.|group=nb}} of each firing stroke.<ref name="Holter38">Holter 2002, p. 38.</ref>

Ground testing of the R involved the use of three [[Rolls-Royce Kestrel|Kestrel]] engines: one to simulate a headwind or [[airspeed]], one to provide ventilation of the test area, and another to cool the [[crankcase]]. Superchargers could be tested on a separate rig that was driven by another Kestrel engine. Eight men were required to run a test cell, led by the "Chief Tester" who had the tasks of logging the figures and directing the other operators. One of these chief testers was Victor Halliwell who later lost his life whilst on board the water speed record contender ''[[Miss England II]]''. The conditions in the test cell were particularly unpleasant; deafness and [[tinnitus]] lasting up to two days were experienced by test personnel even after plugging their ears with [[Cotton#Uses|cotton wool]].<ref name="Holter38"/> Development time was short and the deafening sound of three Kestrels and an R engine running at high power for 24&nbsp;hours a day took its toll on the local population. The [[Mayors in England|Mayor]] of Derby stepped in and asked that the people endure the noise for the sake of British prestige; subsequently testing continued for seven months.<ref name="Holter38"/>

In the course of a 25-minute test an early R engine would consume 60&nbsp;[[Gallon|Imperial gallons]] (gal) (270&nbsp;L) of pre-heated [[castor oil]]. The majority of this was spat out of the exhaust ports and smothered the test cell walls, milk being given to staff to minimise the effects of this well-known [[laxative]]. Up to 200&nbsp;gal (900&nbsp;L) of the special fuel blend had to be mixed for each test, 80&nbsp;gal (360&nbsp;L) of which were used just to warm the engine to operating temperature. The same [[Blade pitch|coarse-pitch]] [[propeller (aircraft)|propeller]] used for flight trials was fitted throughout these tests.<ref name="Holter38"/>

====Flight testing====
Overseen by [[Cyril Lovesey]], flight testing commenced on 4 August 1929 in the new Supermarine S.6 at [[RAF Calshot]], a [[seaplane]] and [[flying boat]] station on [[Southampton Water]] in [[Hampshire]].<ref name="Eves177">Eves 2001, p. 177.</ref> During pre-race [[Scrutineer#Sport|scrutineering]] tests, metal particles were found on two of the engine's 24 [[spark plugs]] indicating a [[piston]] failure which would require an engine re-build or replacement. The competition rules did not allow an engine change, but due to the foresight of [[Ernest Hives, 1st Baron Hives|Ernest Hives]], several Rolls-Royce engineers and mechanics that were familiar with the R had travelled down to [[Southampton]] to witness the trials, and with their assistance one cylinder bank was removed, the damaged piston replaced and the cylinder refurbished. This work was completed overnight and allowed the team to continue in the competition.<ref>Holter 2002, p. 36.</ref>

Engine starting was achieved by a combination of compressed air and a hand-turned [[ignition magneto|magneto]]; however, starting problems were encountered during pre-race testing at Calshot due to moisture in the air and water contamination of the fuel. A complicated test procedure was devised to ensure clean fuel for competition flights since more than 0.3% water content made it unusable.<ref>Holter 2002, p. 40.</ref> As expected, minor engine failures continued to be experienced, and to counter this engines and parts were transported at high speed between Derby and Calshot using an adapted [[Rolls-Royce Phantom I]] motor car. Travelling mostly after dark, this vehicle became known as the ''Phantom of The Night.''<ref name="Holter41">Holter 2002, p. 41.</ref>

===Relationship to the Griffon and Merlin===
[[File:RRGriffonMAM.JPG|thumb|right|alt=A front right view of a black-painted aero engine, the words 'Rolls-Royce' appear in red. The engine has yellow electrical wiring and is sitting on a wooden pallet.|A late-production [[Rolls-Royce Griffon]]]]
According to [[Arthur Rubbra]]'s memoirs, a de-rated version of the R engine, known by the name ''Griffon'' at that time, was tested in 1933. This engine, ''R11'',<ref name="Eves228"/> was used for "Moderately Supercharged Buzzard development" (which was not proceeded with until much later), and bore no direct relationship to the volume-produced [[Rolls-Royce Griffon|Griffon]] of the 1940s.

The pre-production Griffon I shared the R engine's [[Bore (engine)|bore]] and [[Stroke (engine)|stroke]],<ref>[Staff author] 20 September 1945. "[http://www.flightglobal.com/pdfarchive/view/1945/1945%20-%201852.html The Rolls-Royce Griffon]" ''Flight'', p. 309. www.flightglobal.com. Retrieved 29 October 2009.</ref> but was otherwise a completely new design that first ran in the Experimental Department in November 1939.<ref>Lumsden 2003, p. 216.</ref> Although this single engine was never flown, the production version, the Griffon II, first flew in 1941 installed in the [[Fairey Firefly]].<ref>Lumsden 2003, p. 217.</ref> A significant difference between the R and the production Griffon was the re-location of the [[camshaft]] and supercharger drives to the front of the engine to reduce overall length. Another length-reducing measure was the use of a single magneto (the R had two, mounted at the rear), this again was moved to the front of the engine.<ref>Rubbra 1990, p. 118.</ref>

Further possible development work on the R engine was discussed in [[The National Archives (United Kingdom)|The National Archives]]' file AVIA 13/122,<ref>[http://www.nationalarchives.gov.uk/catalogue/displaycataloguedetails.asp?CATID=3071252&CATLN=6&Highlight=&FullDetails=True Royal Aircraft Establishment, proposal relating to destructive testing of Rolls-Royce R engines, October and November 1932] AVIA13/122 (Air Ministry and successors: Royal Aircraft Establishment (from 1988, Royal Aerospace Establishment)). National Archives, Kew (UK). www.nationalarchives.gov.uk. Retrieved 15 October 2009.</ref> which contains a proposal from the [[Royal Aircraft Establishment]] dated October and November 1932, to test four engines to destruction. This document states that there were five engines available for test purposes, the fifth to be used for a standard [[Type certificate|Type Test]] at high revolutions.

Although not directly related to the [[Supermarine Spitfire|Spitfire]], the [[Supermarine]] engineers gained valuable experience of high-speed flight with the S.5 and S.6 aircraft, their next project being the [[Rolls-Royce Goshawk]]-powered [[Supermarine Type 224]] prototype fighter aircraft. Technological advances used in the R engine, such as sodium-cooled valves and spark plugs able to operate under high boost pressures, were incorporated into the [[Rolls-Royce Merlin]] design.<ref>Price 1982, pp. 19–20.</ref> The author Steve Holter sums up the design of the Rolls-Royce R with these words:<ref>Holter 2002, p. 46.</ref>

{{Blockquote|Quite simply the R-type engine was far ahead of its time, a marvel of British skill and ability.|Steve Holter|''Leap Into Legend''}}

==Schneider Trophy use==
{{Main|Schneider Trophy}}
The Schneider Trophy was a prestigious annual prize competition for [[seaplane]]s that was first held in 1913. The 1926 race was the first where all the teams fielded pilots from their armed forces, the [[Air Ministry]] financing a British team known as the [[High Speed Flight RAF|High Speed Flight]] drawn from the [[Royal Air Force]]. Sometimes known simply as The Flight, the team was formed at the [[Marine Aircraft Experimental Establishment]], [[Felixstowe]], in preparation for the 1927 race<ref>
RAF (UK). [http://www.raf.mod.uk/history_old/schneider3.html ''The Schneider Trophy – 70th Anniversary'', The 1927 Race] {{Webarchive|url=https://web.archive.org/web/20070713052520/http://www.raf.mod.uk/history_old/schneider3.html |date=13 July 2007 }}  www.raf.mod.uk. Retrieved 17 October 2009.
</ref> in which Supermarine's Mitchell-designed, [[Napier Lion]]-powered [[Supermarine S.5]]s placed first and second. 1927 was the last annual competition, the event then moving onto a biannual schedule to allow more development time between races. 
[[File:Schneider Trophy 2006-2.jpg|thumb|left|alt=A trophy with a bronze coloured base, above the base is a wave of silver coloured metal. Atop the wave is a silver winged figurine kissing another figurine partly submerged in the wave.|The Schneider Trophy on display at the [[Science Museum (London)|London Science Museum]]]]

During the 1929 race at [[Cowes]] between Great Britain and Italy, [[Richard Waghorn]] flying the [[Supermarine S.6]] with the new Rolls-Royce R engine retained the Schneider Trophy for Great Britain with an average speed of {{convert|328.63|mph|0|abbr=on}}, and also gained the {{convert|50|and|100|km|mi|abbr=on}} world speed records. The records were subsequently beaten when [[Richard Atcherley]] later registered higher speeds when he completed his laps of the circuit.<ref name="times45303">{{Cite newspaper The Times |title=Schneider Race Trophy Held By Britain, 328 Miles An Hour 
|department=News |date=9 September 1929 |page=13 |issue=45303 |column=G }}</ref><ref name="Price11">Price 1986, p. 11.</ref><ref>Eves 2001, pp. 171–197.</ref>{{#tag:ref|The American and French entrants for 1929 withdrew before the start of the contest through a combination of technical problems and lack of training.|group=nb}} The Italian team placed second and fourth using [[Fiat AS.3]] V-12-powered [[Macchi M.52]] aircraft. Another racing seaplane, the [[Fiat C.29]] powered by the [[Fiat AS.5|AS.5]] engine attended the contest but did not compete.<ref>Eves 2001, pp. 244–245.</ref>

More comparable to the R engine was the [[Fiat AS.6]] engine developed for the 1931 contest; effectively a coupled, double AS.5 that suffered from technical problems. With the assistance of Rod Banks, the AS.6 powered the [[Macchi M.C.72]] to a new speed record for piston-powered seaplanes in 1934 of {{convert|440.6|mph|km/h|abbr=on}}, a record that still stands as of 2009.<ref>Gunston 1989, p. 58.</ref>

In 1931 the British Government withdrew financial support, but a private donation of £100,000 from [[Lucy, Lady Houston]] allowed Supermarine to compete on 13 September using the R-powered [[Supermarine S.6B]]. For this race the engine's rating was increased by {{convert|400|to|2300|hp|kW|abbr=on}}.<ref>
RAF (UK). [http://www.raf.mod.uk/history_old/schneider5.html ''The Schneider Trophy – 70th Anniversary'', The Build-up] {{Webarchive|url=https://web.archive.org/web/20081025000611/http://www.raf.mod.uk/history_old/schneider5.html |date=25 October 2008 }}  www.raf.mod.uk. Retrieved 17 October 2009.
</ref> The Italian and French entrants however, failed to ready their aircraft and crews in time for the competition,<ref>Eves 2001, p. 206.</ref> and the remaining British team set both a new world speed record at {{convert|379|mph|km/h|abbr=on}} and, unopposed, won the trophy outright with a third consecutive victory.<ref name="Price11"/> "The Flight" was wound up within weeks of the 1931 win as there were to be no more Schneider Trophy contests.<ref>RAF (UK). [http://www.raf.mod.uk/history_old/schneider6.html ''The Schneider Trophy – 70th Anniversary'', 1931 Report] www.raf.mod.uk. Retrieved 17 October 2009.</ref> The original Trophy is on display in the [[Science Museum (London)|London Science Museum]] along with the S.6B that secured it, as well as the R engine that powered this aircraft for the subsequent airspeed record flight.<ref name="ScienceMuseum">
[http://www.sciencemuseum.org.uk/objects/aeronautics/1932-532.aspx Supermarine Seaplane S.6B, ''S1595'', Inventory number: 1932-532 (exhibit)] {{Webarchive|url=https://web.archive.org/web/20100318070928/http://www.sciencemuseum.org.uk/objects/aeronautics/1932-532.aspx |date=18 March 2010 }}  www.sciencemuseum.org.uk. Retrieved 15 October 2009.
</ref>

==World speed record use==
{{Main|Flight airspeed record|Land speed record|Water speed record}}

New airspeed records were set after the 1929 and 1931 Schneider Trophy contests, both achieved using the R engine. In the two decades before World War II, the quest to break the land speed record was hotly contested, particularly so in the early 1930s. [[Aircraft engine|Aero engines]] were often used to power wheeled vehicles to ever-higher speeds, chosen because of their high [[power-to-weight ratio]]s: the [[Liberty L-12|Liberty engine]], [[Napier Lion]] and the [[Sunbeam Matabele]] were among the engine types used in the 1920s. The Rolls-Royce R was the latest development in high-powered aero engine design at the time, and was chosen by several makers of land speed record-contending cars; the engine was also chosen for [[Powerboating|powerboats]] attempting the water speed record. One car and two boats successfully used the combined power of two R engines.<ref>Holter 2002, pp. 164–171.</ref>

===Airspeed record===

[[File:British team for Schneider Trophy race 1929.jpg|thumb|right|alt=Six uniformed military officers stand in line, the image has a caption, 'British Team for Schneider Trophy Race, 1929.|The 1929 British [[Schneider Trophy]] team. left to right [[Richard Waghorn|Waghorn]], Moon, Grieg, [[Augustus Orlebar|Orlebar]], [[George Stainforth|Stainforth]] and [[Richard Atcherley|Atcherley]].]]
;Supermarine S.6
Immediately after the 1929 Schneider Trophy contest [[Squadron Leader]] [[Augustus Orlebar]], commanding officer of the High Speed Flight, set a new [[Flight airspeed record|airspeed record]] of {{convert|355.8|mph|km/h|abbr=on}} using [[Supermarine S.6]], ''N247.''<ref name="Eves193">Eves 2001, p. 193.</ref>
  
;Supermarine S.6B
On 29 September 1931, barely two weeks after the British team had secured the Schneider Trophy outright, [[Flight Lieutenant]] [[George Stainforth]] broke the world airspeed record in a Rolls-Royce R-powered [[Supermarine S.6B]], serial ''S1595'', reaching an average speed of {{convert|407.5|mph|km/h|abbr=on}}. It had been intended to also use the identical sister aircraft, ''S1596'', for the attempt but Stainforth had capsized it on 16 September whilst testing a propeller.<ref name="Eves210">Eves 2001, p. 210.</ref><ref name="Price10">Price 1986, p. 10.</ref><ref>[Staff author] 25 September 1931. "[http://www.flightglobal.com/pdfarchive/view/1931/1931%20-%201028.html?search=Supermarine%20S.6B ''The Three-Kilometre Record'' – the sinking of ''S1596'']" ''Flight'', p. 966. www.flightglobal.com. Retrieved 29 October 2009.</ref>

===Land speed record===

{{Main|Campbell-Railton Blue Bird|Thunderbolt (car)}}
{{See also|Campbell-Napier-Railton Blue Bird}}
;''Campbell-Railton Blue Bird''
[[File:Campbell Railton Blue Bird Replica.JPG|thumb|left|alt=A front right view of a blue coloured racing car.|''[[Campbell-Railton Blue Bird]]'' replica, an exhibit at the [[Lakeland Motor Museum]]]]
[[Malcolm Campbell|Sir Malcolm Campbell]], and later his son [[Donald Campbell|Donald]], used R engines from 1931 to 1951. At Sir Malcolm's [[Order of the British Empire|knighthood]] ceremony in February 1931, [[George V of the United Kingdom|King George V]] expressed great interest in the R and asked many questions about its fuel consumption and performance.<ref>Jennings 2004, p. 193.</ref>

In 1932, Campbell stated that he "...&nbsp;was fortunate in procuring a special R.R. Schneider Trophy engine" for his land speed record car to replace its [[Napier Lion]]. Lent to him by Rolls-Royce, this engine was either ''R25'' or ''R31''. By February 1933 the car, named ''[[Campbell-Railton Blue Bird|Blue Bird]]'' had been rebuilt to accommodate the larger engine and was running at [[Daytona Beach Road Course|Daytona]].<ref>Jennings 2004, p. 237.</ref>

In late 1933 Campbell bought engine ''R37'' from Rolls-Royce; and had also been lent ''R17'' and ''R19'' by [[Charles Wakefield, 1st Viscount Wakefield|Lord Wakefield]], and ''R39'' by Rolls-Royce. He then lent ''R17'' to [[George Eyston]].<ref name="Holter43"/> Once he had achieved the {{convert|300|mi/h|km/h|abbr=on}} record on 3 September 1935 at the [[Bonneville Speedway]], Campbell retired from further land speed endeavours.<ref>Jennings 2004, p. 273.</ref>

Lord Wakefield arranged for a replica of the Rolls-Royce R to be exhibited at the 1933 [[British International Motor Show|Motor Show]], held at [[Olympia, London]]. A press report from the event<ref>Jennings 2004, p. 236.</ref> provides an insight into the public perception of the engine:

{{Blockquote|Of the size only of an office desk ... this 12-cylinder supercharged racing engine is more powerful than an express locomotive. Its design is stated to be so valuable that it is still on the Government's secret list.|Press report|''The Fast Set''}}

''Blue Bird'' is now on display at the [[Daytona International Speedway]].<ref>Jennings 2002, p. 277.</ref><ref>
{{usurped|1=[https://web.archive.org/web/20091106111938/http://www.sirmalcolmcampbell.com/sirtoday.html Blue Bird at Daytona Speedway]}}  www.sirmalcolmcampbell.com. Retrieved 21 October 2009.
</ref><!-- Presumably without its engine? --> 
;''Thunderbolt''
During the mid-1930s, George Eyston set many speed records with his ''[[Speed of the Wind]]'' car, powered by an unsupercharged [[Rolls-Royce Kestrel]]. In 1937 he built a massive new car, ''[[Thunderbolt (car)|Thunderbolt]]'', powered by two R engines to attempt the absolute land speed record.<ref>Jennings 2004. p. 282.</ref> At first Eyston experienced [[clutch]] failure due to the combined power of the engines. Nevertheless, he took the record in November 1937, reaching {{convert|312|mph|km/h|abbr=on}}, and in 1938 when ''Thunderbolt'' reached {{convert|357.5|mph|km/h|abbr=on}}.<ref name="Jennings291">Jennings 2004, p. 291.</ref> When first built at [[Bean Cars|Bean Industries]] in [[Tipton]], the nearside engine fitted to ''Thunderbolt'' was ''R27'' which had powered ''S1595'' when it set the air speed record in 1931. The other was ''R25'', used by the same aircraft to win the Schneider Trophy two weeks earlier. Eyston had also borrowed ''R17'' from Sir Malcolm Campbell and, with the continuing support that Rolls-Royce extended to both Campbell and Eyston, he also had the option of using ''R39''.<ref name="Holter43"/>

===Water speed record===

{{Main|Miss England II|Miss England III|Blue Bird K3|Blue Bird K4}}
[[File:Miss England II (model).jpg|thumb|right|alt=Two models of speedboats are displayed in a glass cabinet, the nearest model has Miss England II painted on the side, the other, Miss England III|Scale models of ''[[Miss England II]]'' and ''[[Miss England III|III]]'']]
;''Miss England II'' and ''III''
Two R engines, ''R17'' and ''R19'', were built for [[Henry Segrave|Sir Henry Segrave]]'s twin-engined water speed record boat ''[[Miss England II]]'', this craft being ready for trials on [[Windermere]] by June 1930. On [[Friday the 13th|Friday 13]] June, Segrave was fatally injured and a Rolls-Royce technical advisor, Victor Halliwell, was killed when ''Miss England II'' capsized at high speed after possibly hitting a log. Shortly before his death Segrave learnt that he had set a new water speed record of just under {{convert|100|mph|km/h|abbr=on}}.<ref>Jennings 2004, pp. 169–172.</ref><ref>Holter 2002, p. 13.</ref> On 18 July 1932, [[Kaye Don]] set a new world water speed record of {{convert|119.81|mph|km/h|abbr=on}} on [[Loch Lomond]] in a new boat, ''[[Miss England III]]'', which also used engines ''R17'' and ''R19''.<ref name="Holter171"/>

;''Blue Bird K3''
In late 1935, Sir Malcolm Campbell decided to challenge the water speed record. At that point he had two [[Napier Lion]]s and one Rolls-Royce R engine, ''R37'' at his disposal, and it was decided to install the R engine in ''[[Blue Bird K3]]''.<ref>Jennings 2004, p. 298.</ref> During trials on [[Loch Lomond]] in June 1937 the engine was "slightly damaged&nbsp;... because of trouble with the circulating water system". In August 1937 ''Blue Bird K3'' was taken to [[Lake Maggiore]] in Italy where "the modified [circulation] system worked perfectly with a second engine", ''R39''.<ref>Holter 2002, p. 63.</ref>

;''Blue Bird K4 and the work of Leo Villa''
''R39'' was again used in 1939 in ''[[Blue Bird K4]]''. In 1947 Campbell unsuccessfully converted ''K4'' to jet power using a [[de Havilland Goblin]] engine.<ref>Jennings 2004, p. 302.</ref> After Campbell's death from natural causes in 1948,<ref>Jennings 2004, p. 107.</ref> Donald Campbell bought ''K4'' for a nominal sum as well as the 1935 record car when his father's effects were auctioned. He also purchased ''R37'' back from a car dealer and reinstalled it in ''K4''. Attempts on the record were made in 1949, and again in 1951 when ''R37'' was "damaged beyond any immediate repair" by overheating. Another attempt was made later in the year using ''R39'', but ''K4'' suffered a structural failure and sank in [[Coniston Water]]. It was recovered and broken up on the shore.<ref name="Holter87">Holter 2002, p. 87.</ref>

The care and maintenance of the Campbell's R engines was entrusted to [[Leo Villa]], a [[Cockney]] born to a Swiss father, who was described as "the man behind the Campbells" and a central figure who "fitted the first nut to the first bolt". Villa learnt his trade of "aircraft mechanic" in the [[Royal Flying Corps]]; his first job was fitting [[Beardmore 160 hp]] engines to airframes.<ref>Holter 2002, p. 69.</ref> After World War I he worked for a motor racing company and participated as co-driver and mechanic in several races.

Villa was first employed by Malcolm Campbell in 1922, and continued in the service of Donald Campbell until 1967, when Campbell was killed during a record attempt on Coniston Water. He was the chief caretaker of their R engines until the last R-powered record attempt in 1951, after which his responsibilities centred on Campbell's jet engines. Villa's many responsibilities included installing and removing the engines, repairing and tuning them, and operating the compressed air and magneto for starting them. During the World War II years, he was responsible for the upkeep of ''Blue Bird K4'' and the spare R engines, but unknown to him they had been sold along with ''K3''. Villa eventually took the three R engines to [[Thomson & Taylor]] at [[Brooklands]] for long-term storage.<ref>Holter 2002, p. 79.</ref><ref>Jennings 2004, p. 106.</ref>

His relationship with Malcolm Campbell was strained at times: Campbell, with no engineering background, would often question Villa's intimate knowledge of the R engine, but his relations with Donald Campbell were much better, as they were of a similar age. At [[Lake Garda]] in 1951 Villa noted the willingness of "Don" to help with engineering tasks, and the difficulties of working on the R engine:<ref>Holter 2002, p. 85.</ref>

{{Blockquote|I was in the workshop stitching the old ''R37'' back together and had the long job of lapping in all 48 valves. It was a terrible job because the engine was two monoblocs, which meant that you couldn't just lift off the heads, you had to lift what amounted to two separate engines and even then getting the valves in was no easy task. But old Don just rolled up his sleeves and mucked in.|Leo Villa|''Leap Into Legend''}}

===World speed record summary===

[[File:Rolls-Royce R and Supermarine S 6B.jpg|thumb|right|alt=A single-engined floatplane is being built in a hangar, the engine covers are removed.|The Rolls-Royce R installed in a [[Supermarine S.6B]]; engine oil cooling channels are evident on the [[fuselage]]]]

''Note:''{{#tag:ref|Highest record for each aircraft/car/boat type listed only.|group=nb}}
;Air speed record
:[[Supermarine S.6]]: 8 September 1929 – {{convert|355.8|mph|km/h|abbr=on}}<ref name="Eves193"/>
:[[Supermarine S.6B]]: 29 September 1931 – {{convert|407.5|mph|km/h|abbr=on}}<ref name="Lumsden199"/>

;Land speed record
:''[[Campbell-Railton Blue Bird|Blue Bird]]'': 3 September 1935 – {{convert|301|mph|km/h|abbr=on}}<ref>Jennings 2004, p. 272.</ref>
:''[[Thunderbolt (car)|Thunderbolt]]'': 16 September 1938 – {{convert|357.5|mph|km/h|abbr=on}}<ref name="Jennings291"/>
 
;Water speed record
:''[[Miss England II]]'': 9 July 1931 – {{convert|110.28|mph|km/h|abbr=on}}<ref>Holter 2002, p. 170.</ref>
:''[[Miss England III]]'': 18 July 1932 – {{convert|119.81|mph|km/h|abbr=on}}<ref name="Holter171"/>
:''[[Blue Bird K3]]'': 17 August 1938 – {{convert|130.91|mph|km/h|abbr=on}}<ref name="Holter171">Holter 2002, p. 171.</ref>
:''[[Blue Bird K4]]'': 19 August 1939 – {{convert|141.74|mph|km/h|abbr=on}}<ref name="Holter171"/>

==Production and individual engine history==

===Production summary===
[[File:RollsRoyceRrightside.JPG|thumb|right|alt=A rear view of the right side of an aircraft piston engine with details of pipes and electrical wiring|Rear view of ''R27'' showing details of one [[ignition magneto|magneto]], camshaft drive and exhaust ports]]
Nineteen R engines were produced at Derby between 1929 and 1931, all given odd serial numbers. This was a Rolls-Royce convention when the propeller rotated anticlockwise when viewed from the front, but an exception was made for ''R17'', the sole clockwise-rotation R engine. There is some confusion as to whether 19 or 20 R engines were produced. In his notes Leo Villa refers to an ''R18'' engine, but according to Holter this may have been  ''R17'' converted to clockwise rotation at the request of Malcolm Campbell rather than an additional example.<ref>Holter 2002, p. 45.</ref> There was no ''R13'' as Rolls-Royce never used the number 13 in any of their designations. A summary production list is given below:

;1929 Development engines
:''R1'', ''R3'' and ''R5''
;1929 Schneider Trophy engines
:''R7'', ''R9'' and ''R15''
;1930 Development engine
:''R11''
;1930 Wakefield order for ''Miss England II''
:''R17'' and ''R19''
;1931 Schneider Trophy engines
:''R21'', ''R23'', ''R25'', ''R27'', ''R29'' and ''R31''
;1931 Development/factory spare engines
:''R33'', ''R35'', ''R37'' and ''R39''

===Individual history table===

{| class="wikitable" style="border-collapse:collapse"
|-
!Engine !!Date !! Notes !! Display location
|-
|rowspan="3" style="border-bottom:3px #DDDDDD"|'''''R1'''''
|7 April 1929
|Development engine. First test using neat [[benzole]] fuel. No power figures taken.<ref name="Eves226">Eves 2001, p. 226.</ref>
|rowspan="3" style="border-bottom:3px #DDDDDD"|
|-
|1 May 1929
|{{convert|1400|hp|abbr=on}} observed after 13&nbsp;hours running.<ref name="Eves226"/>
|-  
|style="border-bottom:3px #DDDDDD" | 7 May 1929
|style="border-bottom:3px #DDDDDD" | {{convert|1500|hp|abbr=on}} at 2,750&nbsp;rpm, briefly run at {{convert|1686|hp|abbr=on}} at 3,000 rpm. Engine stripped, forked [[connecting rod]]s found cracked. Redesigned rods fitted and [[crankcase]] machined. The crankcase modifications decreased over-oiling by 75%, a new scraper ring was suggested to cure the remainder. Fuel/air distribution problem due to new manifold design – return to the original Buzzard manifold suggested.<ref name="Eves226"/>  
|-
|rowspan="12" style="border-bottom:3px #DDDDDD"|'''''R3'''''
|15 May 1929
|Development engine. Completed 15-minute acceptance test. {{convert|1500|hp|abbr=on}} at 2,750&nbsp;rpm.<ref name="Eves226"/>
|rowspan="12" style="border-bottom:3px #DDDDDD"|
|-
|26 February 1931
|Back in development test house. Spot reading of {{convert|2300|hp|abbr=on}} at 3,200&nbsp;rpm noted.<ref name="Eves229">Eves 2001, p. 229.</ref>
|-
|21 April 1931
|First test with articulated connecting rods.<ref name="Eves229"/>
|-
|23 April 1931
|{{convert|1900|hp|abbr=on}} at 3,200&nbsp;rpm for 17&nbsp;minutes – longest time at this power with new rods.<ref name="Eves229"/>
|-
|24 April 1931
|Failed after 17 minutes when the main bearings collapsed<ref name="Holter37">Holter 2002, p. 37.</ref>
|-
|25 April 1931
|{{convert|2210|hp|abbr=on}} at 3,200&nbsp;rpm. Attempted 1-hour [[Air Ministry]] acceptance test but oil pressure was lost after 22&nbsp;minutes.<ref name="Eves229"/>
|-
|1 May 1931
|Failed after 2.5 minutes when the main bearing and connecting rods failed<ref name="Holter37"/>
|-
|14 May 1931
|Failed after 17.33 minutes when supercharger slipper bushes seized<ref name="Holter37"/>
|-
|15 May 1931
|Two runs of 29.5 minutes and 18.5 minutes, both terminated by broken exhaust valves<ref name="Holter37"/>
|-
|29 May 1931
|Ran for 25 minutes fitted with [[sodium]]-filled valves. Heads failed<ref name="Holter37"/>
|-
|14 July 1931
|Running with [[sodium]]-filled valves.<ref name="Eves229"/>
|-
|style="border-bottom:3px #DDDDDD;" |28 July 1931
|style="border-bottom:3px #DDDDDD;" |Further attempt at the 1-hour test, crankshaft failure after 34&nbsp;minutes. Rebuilt but experienced a second crankshaft failure after 58&nbsp;minutes, power output of {{convert|2360|hp|abbr=on}} at 3,200&nbsp;rpm noted just prior to failure.<ref name="Eves229"/>
|-
|rowspan="3" style="border-bottom:3px #DDDDDD"|'''''R5'''''
|18 June 1929
|Development engine. Completed 15-minute acceptance test. {{convert|1500|hp|abbr=on}} at 2,750&nbsp;rpm.<ref name="Eves227">Eves 2001, p. 227.</ref>
|rowspan="3" style="border-bottom:3px #DDDDDD"|
|-
|7 August 1929
|Completed first 1-hour full-throttle test. {{convert|1568|hp|abbr=on}} at 3,000&nbsp;rpm.<ref name="Eves227"/>
|-
|style="border-bottom:3px #DDDDDD" |25 February 1931
|style="border-bottom:3px #DDDDDD;" |Back in development for 1931 race. Probably this engine that blew up at {{convert|2000|hp|abbr=on}} after [[dynamometer]] coupling failure.<ref name="Eves229"/> 
|-
|rowspan="2" style="border-bottom:3px #DDDDDD"|'''''R7'''''
|6 July 1929
|Passed 15-minute acceptance test. {{convert|1552|hp|abbr=on}}. Issued to [[RAF Calshot|Calshot]] for test flying with minimum use of full throttle.<ref name="Eves227"/>
|rowspan="2" style="border-bottom:3px #DDDDDD"|
|-
|style="border-bottom:3px #DDDDDD" |Mid-September 1929
|style="border-bottom:3px #DDDDDD;" |Post race, installed in S.6, ''N248,'' for speed record attempt.<ref name="Eves228"/>
|-
|rowspan="5" style="border-bottom:3px #DDDDDD"|'''''R9'''''
|4 August 1929
|Installed in S.6, ''N247,'' for sea trials and attempted first flight – aircraft refused to takeoff due to handling problems. All modifications to date were incorporated in this engine.<ref name="Eves177"/>
|rowspan="5" style="border-bottom:3px #DDDDDD"|
|-
|10 August 1929
|First flight, in S.6, ''N247''.<ref name="Eves177"/>
|-
|22 August 1929
|Returned to [[Derby]] having run 4&nbsp;hr 33&nbsp;min on the ground and 2&nbsp;hr 52&nbsp;min in the air. Overhauled and refitted to ''N247'' for the race.<ref name="Eves228">Eves 2001, p. 228.</ref>
|-
|June 1931
|Rebuilt to 1931 specification. {{convert|2165|hp|abbr=on}} at 3,200&nbsp;rpm. Cleared at Calshot for limited full-throttle use.<ref name="Eves229"/>
|-
|style="border-bottom:3px #DDDDDD" |12 August 1931
|style="border-bottom:3px #DDDDDD;" |Back at Derby with new design crankshaft. {{convert|2350|hp|abbr=on}} at 3,200&nbsp;rpm for full hour.<ref name="Eves230"/>
|-
|rowspan="2" style="border-bottom:3px #DDDDDD"|'''''R11'''''
|25 August 1929
|Flown in S.6 ''N248''.<ref name="NotesHSF">[http://www.nationalarchives.gov.uk/catalogue/displaycataloguedetails.asp?CATID=3071242&CATLN=6&Highlight=%2CORLEBAR&accessmethod=0  "Notes on High Speed Flight, 1931" collected by Wing Commander A. H. Orlebar  (T.3209)], AVIA 13/112. National Archives, Kew (UK). www.nationalarchives.gov.uk.: Retrieved: 5 November 2010.</ref> Development engine in 1930.<ref name="Eves228"/>
|rowspan="2" style="border-bottom:3px #DDDDDD"|
|-
|style="border-bottom:3px #DDDDDD" |1930
|style="border-bottom:3px #DDDDDD;" |Redesignated "R-MS-11" for [[Rolls-Royce Buzzard|Buzzard]] MS (moderately supercharged) development.<ref name="Eves228"/>
|-
|rowspan="3" style="border-bottom:3px #DDDDDD"|'''''R15'''''
|7 September 1929
|Probably in S.6, ''N248,'' for the race.<ref name="Eves228"/><ref name="NotesHSF"/>
|rowspan="3" style="border-bottom:3px #DDDDDD"|
|-
|style="border-bottom:3px #DDDDDD" |26 June 1931
|style="border-bottom:3px #DDDDDD;"|Flown in S.6A ''N248,''.<ref name="NotesHSF"/>
|-
|style="border-bottom:3px #DDDDDD" |22 August 1931
|style="border-bottom:3px #DDDDDD;"|Flown in S.6B ''S1595,''.<ref name="NotesHSF"/>
|-
|rowspan="3" style="border-bottom:3px #DDDDDD"|'''''R17'''''
|April 1930
|Direct-drive engine for [[Henry Segrave|Sir Henry Segrave]]'s [[water speed record]] boat ''[[Miss England II]]'', sponsored by [[Charles Wakefield, 1st Viscount Wakefield|Lord Wakefield]].
{{convert|2053|hp|abbr=on}} at 3,000&nbsp;rpm. Water-cooled [[exhaust manifold]]s. This was the only R engine originally made as an anticlockwise unit – hence it had a different crankshaft, camshaft and ancillaries. Contrary to Rolls-Royce convention it was given an odd engine number.<ref name="Eves202">Eves 2001, p. 202.</ref>
|rowspan="3" style="border-bottom:3px #DDDDDD"|
|-
|1935
|Lent by Lord Wakefield to [[Malcolm Campbell|Sir Malcolm Campbell]] as a spare for [[land speed record]] attempt.<ref name="Holter43"/>
|-
|style="border-bottom:3px #DDDDDD" |
|style="border-bottom:3px #DDDDDD;" |Lent by Sir Malcolm Campbell to [[George Eyston]] as a spare for land speed record attempt.<ref name="Holter43"/>
|-
|rowspan="3" style="border-bottom:3px #DDDDDD"|'''''R19'''''
|April 1930
|Direct-drive engine for Sir Henry Segrave's water speed record boat ''Miss England II'', sponsored by Lord Wakefield.
{{convert|2053|hp|abbr=on}} at 3,000&nbsp;rpm.<ref name="Eves202"/>
|rowspan="3" style="border-bottom:3px #DDDDDD"|
|-
|1935
|Lent by Lord Wakefield to Sir Malcolm Campbell as a spare for a land speed record attempt.<ref name="Holter43"/>
|-
|style="border-bottom:3px #DDDDDD;" |30 June 1937
|style="border-bottom:3px #DDDDDD;" |Timed at {{convert|85|mi/h|km/h|abbr=on}} in ''[[Blue Bird K3]]'' with Sir Malcolm Campbell.<ref name="Holter43"/>
|-
|style="border-bottom:3px #DDDDDD;" |'''''R21'''''
|style="border-bottom:3px #DDDDDD;" |6 July 1931
|style="border-bottom:3px #DDDDDD;" |First new 1931 engine, passed final inspection. {{convert|2292|hp|abbr=on}}.<ref name="Eves229"/> Installed in S.6B, ''S1595,'' for first flight 29 July.<ref name="NotesHSF"/>
|style="border-bottom:3px #DDDDDD;" |
|-
|style="border-bottom:3px #DDDDDD;" |'''''R23'''''
|style="border-bottom:3px #DDDDDD;" |30 July 1931
|style="border-bottom:3px #DDDDDD;" |Delivered to Supermarine. Fitted in S.6B ''S1596,'' for first flight 12 August.<ref name="NotesHSF"/>
|style="border-bottom:3px #DDDDDD;" |
|-
|rowspan="3" style="border-bottom:3px #DDDDDD"|'''''R25'''''
|9 September 1931
|Fitted in S6B ''S1596,''.<ref name="NotesHSF"/>
|rowspan="3" style="border-bottom:3px #DDDDDD"|[[Royal Air Force Museum London]].<ref name="RAF">[http://navigator.rafmuseum.org/results.do?view=detail&db=object&pageSize=1&id=33799 Rolls-Royce R (exhibit) at the Royal Air Force Museum London] navigator.rafmuseum.org. Retrieved 15 October 2009.</ref>
|-
|13 September 1931
|Fitted to the S.6B, ''S1596'' for first Air Speed Record runs flown by Flt Lt [[George Stainforth]].<ref name="NotesHSF"/>
|-
|style="border-bottom:3px #DDDDDD;" |
|style="border-bottom:3px #DDDDDD;" |To George Eyston for ''[[Thunderbolt (car)|Thunderbolt]]'' land speed record car.<ref name="Holter43">Holter 2002, p. 43.</ref><br>Later to [[RAF Cranwell]].
|-
|rowspan="3" style="border-bottom:3px #DDDDDD"|'''''R27'''''
|8 September 1931
|Flown in S.6B ''S1596,''<ref name="NotesHSF"/>
|rowspan="3" style="border-bottom:3px #DDDDDD"|[[Science Museum (London)|London Science Museum]].<ref name="ScienceMuseum"/>
|-
|29 September 1931
|Fitted in S.6B ''S1595'' (the Trophy-winning aircraft), and gained the [[air speed record]] at {{convert|407.5|mi/h|km/h|abbr=on}}.<ref name="Eves210"/><ref name="NotesHSF"/>
|-
|style="border-bottom:3px #DDDDDD;" |
|style="border-bottom:3px #DDDDDD;" |To George Eyston for the ''Thunderbolt'' land speed record car.<ref name="Holter43"/>
|-
|rowspan="2" style="border-bottom:3px #DDDDDD"|'''''R29'''''
|3 September 1931
|Third 1931 race engine delivered.<ref name="Eves230"/>
|rowspan="2" style="border-bottom:3px #DDDDDD"|
|-
|style="border-bottom:3px #DDDDDD;" |13 September 1931
|style="border-bottom:3px #DDDDDD;" |Installed in S.6B, ''S1595,'' for the [[Schneider Trophy]] Contest. Aircraft flown by Flt Lt [[John Boothman]] won the Trophy<ref name="NotesHSF"/>
|-
|style="border-bottom:3px #DDDDDD;" |'''''R31'''''
|style="border-bottom:3px #DDDDDD;" |13 September 1931
|style="border-bottom:3px #DDDDDD;" |Last of batch of 6 made for 1931 contest.<ref>Holter 2002, p. 31.</ref> Installed in S.6A ''N248'' as reserve aircraft for the [[Schneider Trophy]] Contest<ref name="NotesHSF"/>
|style="border-bottom:3px #DDDDDD;" |
|-
|style="border-bottom:3px #DDDDDD;" |'''''R33'''''
|style="border-bottom:3px #DDDDDD;" |1933
|style="border-bottom:3px #DDDDDD;" |Development engine for the last two land speed record (LSR) engines. Installed in ''[[Campbell-Railton Blue Bird]]'' during construction at [[Brooklands]].<ref>Holter 2002, p. 71.</ref>
|style="border-bottom:3px #DDDDDD;" |
|-
|style="border-bottom:3px #DDDDDD;" |'''''R35'''''
|style="border-bottom:3px #DDDDDD;" |
|style="border-bottom:3px #DDDDDD;" |Development engine for the last two LSR engines. Thought to have been used as a mock-up model for display only.
|style="border-bottom:3px #DDDDDD;" |
|-
|rowspan="3" style="border-bottom:3px #DDDDDD"|'''''R37'''''
|Late-1933
|Bought from Rolls-Royce for £5,800 by Sir Malcolm Campbell for use in the ''Campbell-Railton Blue Bird'' car.<ref name="Holter42"/>
|rowspan="3" style="border-bottom:3px #DDDDDD"|Filching Manor Motor Museum 
|-
|July/August 1937
|Fitted into ''Blue Bird K3'' by [[Saunders-Roe]] on initial build, later overheated and damaged due to cooling scoop problems.<ref>Holter 2002, p. 29.</ref><ref name="Holter44">Holter 2002, p. 44.</ref>
|- 
|style="border-bottom:3px #DDDDDD;" |17 August 1949
|style="border-bottom:3px #DDDDDD;" |In ''[[Blue Bird K4]]'' with [[Donald Campbell]]. This replaced the [[De Havilland Goblin|Goblin]] jet engine installed unsuccessfully by Sir Malcolm Campbell.<ref>Holter 2002, p. 30.</ref>
|-
|rowspan="8" style="border-bottom:3px #DDDDDD"|'''''R39'''''
|1935
|"Factory spare" lent by Rolls-Royce to Sir Malcolm Campbell as a back-up (he already owned ''R37'') for the 1935 land speed record attempt.<ref name="Holter43"/>
|rowspan="8" style="border-bottom:3px #DDDDDD"|
|-
|
|Option given to George Eyston to use this engine as a spare for the ''Thunderbolt'' car.<ref name="Holter43"/>
|-
|July/August 1937
|Replaced  ''R37'' in ''Blue Bird K3'' by Sir Malcolm Campbell.<ref name="Holter44"/>
|-
|1 September 1937
|Takes water speed record in ''K3'' at {{convert|126.32|mi/h|km/h|abbr=on}}.<ref name="Holter171"/>
|-
|17 August 1938
|In ''[[Blue Bird K4]]'' raises water speed record again to {{convert|130.91|mph|km/h|abbr=on}} with Sir Malcolm Campbell.<ref name="Holter171"/>
|-
|19 August 1939
|In ''Blue Bird K4,'' new record of {{convert|141.74|mph|km/h|abbr=on}} by Sir Malcolm Campbell on Coniston Water.<ref name="Holter171"/>
|-
|10 June 1951
|In ''Blue Bird K4'' with Donald Campbell, after ''R37'' was damaged by overheating.<ref>Holter 2002, p. 84.</ref> 
|-
|10 September 1951
|Sank at [[Coniston Water]] in ''Blue Bird K4'' during water speed record attempt by Donald Campbell, salvaged, hull broken up and burnt on the shore. Suspected structural failure of the boat's engine mounts after driveshaft breakage at {{convert|170|mph|km/h|abbr=on}}.<ref name="Holter87"/>
|}

==Applications==
[[File:Supermarine S.6B ExCC.jpg|thumb|right|alt=A single-engined monoplane seaplane aircraft is mounted on a wheeled trolley, ten men are standing by the aircraft with one looking into the opened cockpit. The aircraft has 'S1596' painted on the tail.|The R-powered [[Supermarine S.6B]], ''S1596'']]
;Aircraft
*[[Supermarine S.6]]
*[[Supermarine S.6|Supermarine S.6A]]
*[[Supermarine S.6B]]
;Cars
*''[[Campbell-Railton Blue Bird]]''
*''[[Thunderbolt (car)|Thunderbolt]]''
;Boats
*''[[Blue Bird K3]]''
*''[[Blue Bird K4]]''
*''[[Miss England II]]''
*''[[Miss England III]]''

==Engines on display==
[[File:RollsRoyceR.JPG|thumb|right|alt=A front right view of a large, black-painted, piston aircraft engine with a prominent propeller shaft. A camouflaged military aircraft is parked behind.|Rolls-Royce R, ''R25,'' at the [[Royal Air Force Museum London]]]]
;''R25''
The [[Royal Air Force Museum London]] at Hendon has a Rolls-Royce R on display (museum number 65E1139) that came to the museum in November 1965 from [[RAF Cranwell]]. According to the museum's records, before that it was with George Eyston as one of ''[[Thunderbolt (car)|Thunderbolt's]]'' record engines. Its data plate states that it is ''R25'' under [[Air Ministry]] contract number A106961 which makes it the second 1931 race engine delivered to [[RAF Calshot]].<ref name="RAF"/> 
;''R27''
The [[Science Museum (London)|London Science Museum]] has an R engine on display which is catalogued as a stand-alone item, inventory number 1948-310. This is ''R27'', the second sprint engine prepared for the successful air speed record attempt,<ref name="Eves210"/> and later used in ''Thunderbolt''. The Science Museum also has S.6B, ''S1595'', (winner of the 1931 race and the final air speed record aircraft) on display.<ref name="ScienceMuseum"/>
;''R37''
The Filching Manor Motor Museum has ''R37'' which is destined to be fitted in its restoration of the ''Blue Bird K3'' water speed record boat.

These three engines are the only ones listed by the British Aircraft Preservation Council/Rolls-Royce Heritage Trust. The [[Solent Sky]] museum's S.6A, ''N248,'' (a competing aircraft in the 1929 race as an S.6, and stand-by for the 1931 race, modified as an S.6A) does not contain an R engine.<ref>Ellis 2004, p. 75.</ref>

==Specifications (R – 1931)==
[[File:Rolls-Royce R Side View.jpg|thumb|300px|right|alt=A right side view of an aircraft piston engine|The Rolls-Royce R]]
{{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= ''Lumsden and Holter.<ref name="Lumsden199"/><ref name="Holter175"/>''
|type=12-cylinder, supercharged, liquid-cooled, 60° [[V12 engine|"V"]], aircraft piston engine
|bore={{convert|6|in|mm|1|abbr=on}}
|stroke={{convert|6.6|in|mm|1|abbr=on}}
|displacement={{convert|2239|cuin|L|1|abbr=on}}
|length={{convert|100|in|mm|abbr=on}}
|diameter=
|width={{convert|32|in|mm|abbr=on}}
|height={{convert|42|in|mm|abbr=on}}
|weight={{convert|1,640|lb|kg}}
|valvetrain=Two intake and two exhaust valves per cylinder with [[sodium]]-cooled exhaust valve stems, actuated via a single [[overhead camshaft]] on each bank
|supercharger=Single-speed [[centrifugal type supercharger]], ratio 7.47:1, maximum +18&nbsp;lb boost at 24,000&nbsp;impeller rpm
|turbocharger=
|fuelsystem=Four duplex updraught Rolls-Royce/[[Claudel-Hobson]] [[carburetor|carburettors]] 
|fueltype=30% [[benzole]], 60% [[methanol]], 10% [[acetone]], plus 4.2&nbsp;cc of [[tetra-ethyl lead]] per gallon
|oilsystem=[[Dry sump]] with one pressure pump and two scavenge pumps, [[Castor oil|pure castor oil]]
|coolingsystem=70% water and 30% [[ethylene glycol]] coolant mixture, pressurised
|power={{convert|2,530|hp|kW|abbr=on}} at 3,200&nbsp;rpm
|specpower=1.13&nbsp;hp/cu in (51.41&nbsp;kW/L)
|compression=6:1
|fuelcon=3.5&nbsp;gal/min (16&nbsp;L/min)
|specfuelcon=0.85&nbsp;pt/hp/hr
|oilcon=14&nbsp;imp gal/hr (64&nbsp;L/h)
|power/weight=1.54&nbsp;hp/lb (2.54&nbsp;kW/kg)
|reduction_gear=0.605:1, right-hand tractor
|general_other=
|components_other=
|performance_other=
}}

==See also==
{{aircontent
<!-- other related articles that have not already linked: -->
|see also=
*[[Rolls-Royce aircraft piston engines]]
<!-- designs which were developed into or from this aircraft: -->
|related=
*[[Rolls-Royce Buzzard]]
*[[Rolls-Royce Griffon]]
<!-- 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=
*[[Fiat AS.6]]
*[[Mikulin AM-38]]
<!-- See [[WP:Air/PC]] for more explanation of these fields. -->
}}

==References==

===Footnotes===
{{reflist|group=nb}}

===Citations===
{{reflist}}

===Bibliography===
{{refbegin}}
*Ellis, Ken. ''Wrecks and Relics - 19th Edition'', Midland Publishing, Hinckley, Leicestershire. 2004. {{ISBN|1-85780-183-0}}
*Eves, Edward. ''The Schneider Trophy Story''. Shrewsbury, UK: Airlife Publishing Ltd., 2001. {{ISBN|1-84037-257-5}}.
*Gunston, Bill. ''World Encyclopaedia of Aero Engines''. Cambridge, UK: Patrick Stephens Limited, 1989. {{ISBN|1-85260-163-9}}
*Gunston, Bill. ''Development of Piston Aero Engines''. Cambridge, UK: Patrick Stephens Limited, 2006. {{ISBN|0-7509-4478-1}}
*Holter, Steve. ''Leap into Legend''. Wilmslow, Cheshire, UK: Sigma Press, 2002. {{ISBN|1-85058-804-X}}
*Jennings, Charles. ''The Fast Set''. London, UK: Abacus, Little, Brown Book Group, 2004. {{ISBN|978-0-349-11596-2}}
*Lumsden, Alec. ''British Piston Engines and their Aircraft''. Marlborough, Wiltshire, UK: Airlife Publishing, 2003. {{ISBN|1-85310-294-6}}.
*Price, Alfred. ''The Spitfire Story'' Second edition. London, UK: Arms and Armour Press Ltd., 1986. {{ISBN|0-85368-861-3}}.
*Rubbra, A.A. ''Rolls-Royce Piston Aero Engines – a designer remembers'' Historical Series (16) Rolls-Royce Heritage Trust, 1990. {{ISBN|1-872922-00-7}}
{{refend}}

==External links==
{{Commons category}}
*[https://www.youtube.com/watch?v=194UlnSpBBo 1929 Schneider Trophy, original footage and soundtrack] ''Note:'' Requires [[Flash Video]] to view.
*{{usurped|1=[https://web.archive.org/web/20100905110525/http://www.sirmalcolmcampbell.com/sir33motorx.html Campbell-Railton Blue Bird, ''The Motor'', 10 January 1933 – Design details]}}
*[https://web.archive.org/web/*/http://www.rolls-royce.com/Images/cs_rolls_tcm92-5496.pdf Rolls-Royce.com, 2002 C.S. Rolls lecture – Details and image of the Rolls-Royce R (Pages 12–13)]

{{RRaeroengines}}

{{featured article}}

[[Category:Rolls-Royce aircraft piston engines|R]]
[[Category:1920s aircraft piston engines]]
[[Category:V12 aircraft engines]]