Jump to content

Rolls-Royce Griffon: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous edit
Content deleted Content added
VisualWikitext
TomTheHand (talk | contribs)
19,190 edits
m Category:Rolls-Royce aircraft piston engines
→Variants: Changed centimetres to millimetres to give whole number.
 
(420 intermediate revisions by more than 100 users not shown)
Line 1: Line 1:
{{short description|1930s British piston aircraft engine}}
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. -->
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. -->
{{Use dmy dates|date=September 2020}}
[[Image:Rolls Royce Griffon.jpg|right|thumb|300px|Rolls-Royce Griffon]]
{|{{Infobox aircraft begin
|name= Griffon
|image= File:Rolls Royce Griffon.jpg
|caption=Preserved Rolls-Royce Griffon with cutaway sections.
}}{{Infobox Aircraft Engine
|type=[[Coolant#Liquids|Liquid-cooled]] [[V12 engine|V-12]] [[Four-stroke engine|four-stroke]] [[Reciprocating engine|piston]] [[aero engine]]
|manufacturer=[[Rolls-Royce Limited|Rolls-Royce]]
|first run=November 1939
|major applications=[[Avro Shackleton]]<br />[[Fairey Firefly]]<br />[[Supermarine Spitfire]]
|number built = 8,108
|program cost =
|unit cost =
|developed from =
|developed into =
|variants with their own articles =
}}
|}


The '''Rolls-Royce Griffon''' was a 2,240 in³ (36.75 L), 60-degree [[v12|V-12]] [[aero-engine]], developed from the earlier '''[[Rolls-Royce R]]''' racing engine used in the [[Schneider Trophy]] races.
The '''Rolls-Royce Griffon''' is a British 37-[[litre]] (2,240&nbsp;[[cubic inch|cu in]]) [[Engine displacement|capacity]], 60-degree [[V12 engine|V-12]], liquid-cooled [[Aircraft engine|aero engine]] designed and built by [[Rolls-Royce Limited]]. In keeping with company convention, the Griffon was named after a [[bird of prey]], in this case the [[griffon vulture]].


Design work on the Griffon started in 1938 at the request of the [[Fleet Air Arm]], for use in new aircraft designs such as the [[Fairey Firefly]]. In 1939 it was also decided that the engine could be adapted for use in the [[Supermarine Spitfire (Griffon powered variants)|Spitfire]]. Development was stopped temporarily to concentrate efforts on the smaller [[Rolls-Royce Merlin|Merlin]] and the 24-cylinder [[Rolls-Royce Vulture|Vulture]]; the engine did not go into production until the early 1940s.
==Development==
The '''Griffon''' was designed prior to [[World War II]] and was originally intended as a low-altitude engine for naval aircraft such as the [[Fairey Firefly]] but a formal suggestion to fit a Griffon in a [[Supermarine Spitfire|Spitfire]] was made by [[Joseph Smith (aircraft designer)|Joe Smith]], who had taken over as Chief Designer at Supermarine's after [[R. J. Mitchell|Mitchell]]'s death, in October 1939. However, work by [[Rolls-Royce plc|Rolls-Royce]] on the engine had been halted temporarily to concentrate on the smaller 1,640 in³ (27 L) [[Rolls-Royce Merlin|Merlin]] which had already surpassed the output achieved with the early Griffon.


The Griffon was the last in the line of V-12 aero engines to be produced by Rolls-Royce with production ceasing in 1955. Griffon engines remain in [[Royal Air Force]] service today with the [[Battle of Britain Memorial Flight]].
When the development work on the Griffon was resumed, it was decided to fit the engine to a Spitfire. The first example of this was a single Spitfire Mk.IV, ''DP845'', a modified clipped-wing Spitfire Mk.III which flew with a '''Griffon RG 2SM''' on [[27 November]] [[1941 in aviation|1941]].


==Design and development==
[[Image:Spitfire IV XII DP845.jpg|thumb|left|250px|The first Griffon-[[Supermarine Spitfire|Spitfire]], ''DP845'']]


===Origins===
Pilot conversion from Merlin-engined to Griffon-engined Spitfires was not without teething troubles, the most common problem being the ingrained habit of applying a starboard trim to the aircraft's rudder to offset the tremendous torque produced at takeoff power. As the Griffon's crankshaft rotated in the opposite direction to that of the Merlin (a legacy of its intended use for naval aircraft), a starboard bias increased, instead of compensating for, the undesirable effects of torque. This problem was never fully overcome in land-based Spitfires, although the Seafire FR.47 was fitted with a contra-rotating propeller as standard, thus negating airscrew torque.
[[File:Spitfire IV XII DP845.jpg|thumb|right|The first Griffon-powered Spitfire IV, ''DP845'']]
According to [[Arthur Rubbra]]'s memoirs, a de-rated version of the "[[Rolls-Royce R|R]]" engine, known by the name ''Griffon'' at that time, was tested in 1933. This engine, ''R11'',<ref>Eves 2001, p. 228.</ref> which was never flown, was used for "Moderately Supercharged Buzzard development" (which was not proceeded with until much later), and bore no direct relationship to the volume-produced Griffon of the 1940s.


In 1938, the Fleet Air Arm approached Rolls-Royce and asked whether a larger version of the Merlin could be designed. The requirements were that the new engine have good power at low altitude and that it be reliable and easy to service.<ref name="Flt309.">Flight 1945, p. 309.</ref> Work began on the design of the engine soon afterwards.{{#tag:ref|Although the ''Griffon'' from 1933 shared the R engine's [[Bore (engine)|bore]] and [[Stroke (engine)|stroke]] with the Griffon I of 1939, the Griffon I was a completely new design.<ref name="Flt309."/>|group=nb}} The design process was relatively smooth compared with that of the Merlin, and the first of three prototype Griffon Is first ran in the Experimental Department on 30 November 1939.<ref>Lumsden 2003, p. 216.</ref><ref name="Morgan and Shacklady 2000, p. 133.">Morgan and Shacklady 2000, p. 133.</ref>
Rolls-Royce applied the advances in supercharging used on the Merlin to the Griffon, and later Griffon versions featured two-stage supercharging and finally a two-stage, three-speed supercharger.


Although the Griffon was designed for naval aircraft, on 8 November 1939 N E Rowe of the [[Air Ministry]] suggested fitting the Griffon in a [[Supermarine Spitfire|Spitfire]]. Three weeks later, permission was given to [[Supermarine]] to explore the possibilities of adapting the Griffon to the Spitfire; in response, Supermarine issued 'Specification 466' on 4 December. This decision led to a change in the disposition of the engine accessories to reduce the frontal area of the engine as much as possible.<ref name="Morgan and Shacklady 2000, p. 133."/> As a result, the frontal area of the bare Griffon engine was {{convert|7.9|sqft|m2}} compared with {{convert|7.5|sqft|m2}} of the Merlin, despite the Griffon's much larger capacity.<ref>Morgan and Shacklady 2000, p. 134.</ref> This redesigned engine first ran on 26 June 1940 and went into production as the Griffon II.
The two-stage, three-speed Griffon 101 was fitted to the two [[Supermarine Spiteful]] XVIs (re-engined production Mk.XIVs) with one of these aircraft, ''RB518'', achieving a maximum speed of 494 mph (795 km/h) with full military equipment.


In early 1940, with the expected [[Battle of Britain]] looming, on the orders of [[Max Aitken, 1st Baron Beaverbrook|Lord Beaverbrook]], [[Minister of Aircraft Production]], work on the new engine had been halted temporarily to concentrate on the smaller 27&nbsp;L ({{nowrap|1,650 cu in}}) Merlin which had already surpassed the output achieved with the early Griffon.
The Griffon was also used in the [[Avro Shackleton]] maritime patrol aircraft.


===Design===
==Variants{{ref|spitsoc}}==
[[File:Fairey Firefly Engine CWHM 1.jpg|thumb|right|upright|A Griffon installed on ''WH632'', an airworthy [[Fairey Firefly]] at the [[Canadian Warplane Heritage Museum]] (2014) ]]
* '''Griffon II''' - 1,730 hp (1,290 kW) at 750 ft (230 m) and 1,490 hp (1,110 kW) at 14,000 ft (4,270 m); used on [[Fairey Firefly|Firefly Mk.I]] fighter
Compared with earlier Rolls-Royce designs, the Griffon engine featured several improvements, which meant that it was physically only slightly larger than the Merlin, in spite of its 36% larger capacity of 37-[[litre]]s (2,240&nbsp;[[cubic inch|cu in]]).<ref name="Flt309."/>
* '''Griffon VI''' - increased maximum boost pressure, 1,850 hp (1,380 kW) at 2,000 ft (610 m); used on [[Supermarine Spitfire|Seafire]] Mk.XV and Mk.XVII

* '''Griffon 57''' - 1,960 hp (1,460 kW); used on [[Avro Shackleton]]
One significant difference was the incorporation of the [[camshaft]] and [[ignition magneto|magneto]] drives into the propeller [[Gear ratio|reduction gears]] at the front of the engine, rather than using a separate system of gears driven from the back end of the [[crankshaft]]; this allowed the overall length of the engine to be reduced as well as making the drive train more reliable and efficient.<ref name="Flt312.">Flight 1945, p. 312.</ref>{{#tag:ref|Incorporating four sets of gears (two camshaft drives, plus propeller reduction gears and magneto drive) into one unit meant that the extra group of gears for the magnetos and camshafts, which were normally mounted at the rear of the crankshaft, could be omitted.|group=nb}} The drive for the supercharger was also taken from the front of the engine, which required a long shaft to run to its location at the back of the engine.<ref name="The Aeroplane 1945, pp. 1, 3, 6">The Aeroplane 1945, pp. 1, 3, 6.</ref>
* '''Griffon 61''' - introduced a two-speed two-stage [[supercharger]] with aftercooler similar to that on Merlin 61; 2,035 hp (1,520 kW) at 7,000 ft (2,135 m) and 1,820 hp (1,360 kW) at 21,000 ft (6,400 m); used on Spitfire Mk.21

* '''Griffon 65''' - similar to Griffon 61 with different propeller reduction gear; used on Spitfire Mk.XIV
The Merlin engine's crankshaft lubrication was via a gallery cut into the engine block to feed each main bearing and then onto a secondary adjacent [[Crankpin|big end bearing]] via a gallery in the crankshaft itself. The crankpin was second in line to the main bearing in oil flow and pressure, with oil having to flow through the main bearing first. The Griffon improved on this arrangement being the first Rolls-Royce production aero engine to use a hollow crankshaft as the means of lubricating the main and big end bearings, with oil being fed from each end of the crankshaft giving even flow to all bearings.<ref name="Flt312."/><ref>{{Cite web|url=http://thunderboats.ning.com/page/rolls-royce-griffon-engine|title=Rolls-Royce Griffon Engine}}</ref>
* '''Griffon 72''' - increased maximum boost pressure to take advantage of 150-[[octane rating|grade]] fuel; 2,245 hp (1,675 kW) at 9,250 feet (2,820 m)

* '''Griffon 74''' - fuel-injected version of Griffon 72; used on Firefly Mk.IV
In another change from convention, one high efficiency [[British Thomson-Houston|B.T.H]]-manufactured dual magneto was mounted on top of the propeller reduction casing;<ref>Flight 1945, pp. 312, 314.</ref> earlier Rolls-Royce designs using twin magnetos mounted at the rear of the engine.<ref>Rubbra 1990, p. 118.</ref>
* '''Griffon 83''' - modified to drive [[contra-rotating propellers]]; 2,340 hp (1,745 kW) at 750 ft (230 m) and 2,100 hp (1,565 kW) at 12,250 ft (3,740 m)

* '''Griffon 85''' - 2,375 hp (1,770 kW); used on [[Supermarine Spiteful|Spiteful Mk.XIV]]
The Griffon 61 series introduced a two-stage supercharger and other design changes: the pressure oil pumps were now housed internally within the sump and an effort was made to remove as many external pipes as possible.<ref>The Aeroplane 1945, pp. 1, 8.</ref> In addition, the drive for the supercharger was moved to the crankshaft at the back of the engine, via a short torsion shaft, rather than at the front of the engine, using a long drive shaft as used by earlier Griffon variants.<ref name="The Aeroplane 1945, pp. 1, 3, 6"/>
* '''Griffon 89''' - 2,350 hp (1,755 kW); used on Spiteful Mk.XV

* '''Griffon 101''' - 2,420 hp (1,805 kW); used on Spiteful Mk.XVI
Production of the aero version of the Griffon ended in December 1955, while a marine version, the '''Sea Griffon''', continued to be produced for the RAF's High Speed Launches.<ref>Flight 1956, p. 578.</ref>

===Basic component overview (Griffon 65)===
''From Jane's and Flight.''<ref>Bridgman 1989, pp. 279–280.</ref><ref>[Staff author] 20 September 1945. "[http://www.flightglobal.com/pdfarchive/view/1945/1945%20-%201852.html The Rolls-Royce Griffon]" ''Flight'', pp. 309–316. www.flightglobal.com. Retrieved: 29 October 2009.</ref>
[[File:RR Griffon.jpg|thumb|right|Griffon, cut away to show camshaft drives etc., at the Battle of Britain Museum at RAF Coningsby]]
;Cylinders
:Twelve cylinders consisting of high-carbon steel, floating [[wet liner]]s<ref name="Flt313.">Flight 1945, p. 313.</ref> set in two, two-piece cylinder blocks of cast [[aluminium alloy]] having separate heads and skirts. Cylinder liners [[chromium]] plated in the bores for {{cvt|2.5|in}} from the head.<ref name="Flt313."/> Cylinder blocks mounted with an included 60-degree angle onto inclined upper faces of a two-piece crankcase. Cylinder heads fitted with cast-iron inlet valve guides, [[phosphor bronze]] exhaust valve guides, and renewable "Silchrome" steel-alloy valve seats. Two diametrically opposed [[spark plug]]s protrude into each [[combustion chamber]].
;Pistons
:Machined from "[[Hiduminium|R.R.59]]" alloy [[forging]]s. Fully floating [[gudgeon pin]]s of hardened nickel-chrome steel. Two [[Internal combustion engine#Compression ignition process|compression]] and one drilled oil-control [[Piston ring|ring]] above the gudgeon pin, and another drilled oil-control ring below.
;Connecting rods
:H-section machined nickel-steel forgings, each pair consisting of a plain and a forked [[Connecting rod|rod]]. The forked rod carries a nickel-steel bearing block which accommodates steel-backed lead-bronze-alloy bearing shells. The "small-end" of each rod houses a floating phosphor bronze [[Bushing (bearing)|bush]].
;Crankshaft
:One-piece, machined from a [[Nitriding|nitrogen-hardened]] nickel-chrome [[molybdenum]] steel forging. [[Engine balance|Statically and dynamically balanced]]. Seven main bearings and six throws. Internal oilway, with feed from both ends, used to distribute lubricants to main and big end bearings.<ref name="Flt312."/> "Floating" front end bearing consisting of an internally toothed annulus bolted to crankshaft, meshing with and incorporating a semi-floating ring, internally [[Rotating spline|splined]] to a short [[coupling]] shaft. Coupling shaft splined at front end to driving wheel of propeller reduction gear.<ref name="Flt312."/> Clockwise rotation when viewed from rear.
;Crankcase
:Two aluminium-alloy castings joined together on the horizontal centreline. The upper portion bears the wheelcase, cylinder blocks and part of the housing for the [[Propeller speed reduction unit|airscrew reduction gear]]; and carries the crankshaft main bearings (split mild-steel shells lined with lead–bronze alloy). The lower half forms an oil sump and carries the main pressure oil pump, supercharger change-speed operating pump and two scavenge pumps. It also houses the main coolant pump which is driven through the same gear-train as the oil pumps.
;Wheelcase
:Aluminium-alloy casting fitted to rear of crankcase. Carries the supercharger; and houses drives to the supercharger, auxiliary gearbox coupling, engine speed indicator, airscrew constant-speed unit, intercooler pump and fuel pump, as well as the oil and coolant pumps in the lower half crankcase.
;Valve gear
:Two inlet and two exhaust [[poppet valve]]s of "[[Kayser, Ellison and Co Ltd|K.E.965]]" austenitic nickel-chrome steel per cylinder. Exhaust valves have [[sodium]]-cooled stems. "[[Brightray]]" (nickel-chromium) protective coating to the whole of the combustion face and seat of the exhaust valves, and to the seat only of the inlet valves. Each valve is held closed by a pair of concentric [[coil spring]]s. A single, seven-bearing camshaft, located centrally on the top of each cylinder head operates 24 individual steel [[Rocker arm|rockers]]; 12 pivoting from a rocker shaft on the inner, intake side of the block to actuate the exhaust valves, the others pivoting from a shaft on the exhaust side of the block to actuate the inlet valves.

===Engine capacity, mass flow, and supercharging===
Although it is common practice to compare different piston engines and their performance potential by referring to the [[Engine displacement|engine displacement or swept volume]], this does not give an accurate reading of an engine's capabilities. According to [[Cyril Lovesey|A C Lovesey]], who was in charge of the Merlin's development,{{#tag:ref|After helping design the two-stage, two-speed supercharger for the Merlin Lovesey went on to help develop the Rolls-Royce jet engines; although the quote refers to the Merlin it applies equally as well to the Griffon.|group=nb}} "The impression still prevails that the static capacity known as the swept volume is the basis of comparison of the possible power output for different types of engine, but this is not the case because the output of the engine depends solely on the mass of air it can be made to consume efficiently, and in this respect the supercharger plays the most important role."<ref>Lovesey 1946, p. 218.</ref>

Unlike the Merlin, the Griffon was designed from the outset to use a single-stage supercharger driven by a two-speed, hydraulically operated gearbox; the initial production versions, the Griffon II, III, IV, and VI series, were designed to give their maximum power at low altitudes and were mainly used by the Fleet Air Arm. The Griffon 60, 70, and 80 series featured two-stage supercharging and achieved their maximum power at low to medium altitudes. The Griffon 101, 121, and 130 series engines, collectively designated ''Griffon 3 SML'',<ref name="Fli46,34.">Flight 1946, p. 34.</ref> used a two-stage, three-speed supercharger, adding a set of "Low Supercharger (L.S)" gears to the already existing Medium and Full Supercharger (M.S and F.S) gears.<ref name="Fli46,34."/> Another modification was to increase the diameters of both impellers, thus increasing the rated altitudes at which maximum power could be generated in each gear.<ref name="Fli46,3435.">Flight 1946, pp. 34–35.</ref> While the 101 continued to drive a five-blade propeller, the 121 and 130 series were designed to drive contra-rotating propellers.<ref name="Fli46,34."/> In 1946 a Griffon 101 was fitted to the [[Supermarine Spiteful]] XVI, ''RB518'' (a re-engined production Mk.XIV); this aircraft achieved a maximum speed of 494&nbsp;mph (795&nbsp;km/h) with full military equipment.<ref>Morgan and Shacklady 2000, pp. 501, 503.</ref>

===Pilot transition===
Pilots who converted from the Merlin to the Griffon-engined Spitfires soon discovered that, because the Griffon engine's propeller rotated in the opposite direction to that of the Merlin, the fighter swung to the right on takeoff rather than to the left.<ref name="Lum217."/>{{#tag:ref|The propeller of the Griffon rotated to the left (counter-clockwise) when viewed from the cockpit.|group=nb}} This tendency was even more marked with the more powerful 60- and 80-series Griffon engines, with their five-bladed propellers. As a result, pilots had to learn to apply left (port) trim on takeoff, instead of the right (starboard) trim they were used to applying.<ref>Price 1995, pp. 29, 32–33.</ref> On takeoff, the throttle had to be opened slowly, as the pronounced swing to the right could lead to "crabbing" and severe tyre wear.<ref>Air Ministry 1946, paragraph 49 (i), pp. 26–27</ref>

Some test Spitfire XIVs, 21s, and 24s were fitted with [[contra-rotating propellers]], which eliminated the torque effect. Early problems with the complex gearbox that was required for contra-rotating propellers prevented them from ever becoming operational in Spitfires, but they were used on later aircraft, including the [[Supermarine Seafire|Seafire]] FR. Mk 46 and F and FR.47, which were fitted with Griffon 87s driving contra-rotating propellers as standard equipment.<ref>Morgan and Shacklady 2000, pp. 573, 579, 580.</ref> The Griffon 57 and 57A series, installed in [[Power-egg#United Kingdom|Universal Power Plant]] (UPP) installations and driving contra-rotating propellers, was used in the [[Avro Shackleton]] maritime patrol aircraft.<ref name="Carv09">Carvell 2010, p. 57.</ref>

==Variants==
The Griffon was produced in approximately 50 different variants, the '''Griffon 130''' being the last in the series. Details of representative variants are listed below:
* '''Griffon IIB'''
:1,730&nbsp;hp (1,290&nbsp;kW) at 750&nbsp;ft (230&nbsp;m) and 1,490&nbsp;hp (1,110&nbsp;kW) at 14,000&nbsp;ft (4,270&nbsp;m); Single-stage two-speed supercharger; impeller diameter 10&nbsp;in (254&nbsp;mm); gear ratios 7.85:1, 10.68:1.<ref name="Lum217.">Lumsden 2003, p. 217.</ref> Used on [[Fairey Firefly|Firefly Mk.I]] and [[Supermarine Spitfire (Griffon powered variants)|Spitfire XII]].
* '''Griffon VI'''
:Increased maximum boost pressure, 1,850&nbsp;hp (1,380&nbsp;kW) at 2,000&nbsp;ft (610&nbsp;m); impeller diameter 9.75&nbsp;in (247&nbsp;mm).<ref name="Lum217."/> Used on [[Supermarine Spitfire|Seafire]] Mk.XV and Mk. XVII, Spitfire XII.
[[File:Griffon58.JPG|thumb|right|A Rolls-Royce Griffon 58 displayed at the [[Shuttleworth Collection]] (2008)]]
* '''Griffon 57 and 57A'''
:1,960&nbsp;hp (1,460&nbsp;kW); 2,345&nbsp;hp (1,749&nbsp;kW) with water-methanol injection on take-off: used on [[Avro Shackleton]].<ref name="Carv09"/>
* '''Griffon 61'''
:Introduced a two-speed two-stage [[supercharger]] with aftercooler similar to that on Merlin 61; 2,035&nbsp;hp (1,520&nbsp;kW) at 7,000&nbsp;ft (2,100&nbsp;m) and 1,820&nbsp;hp (1,360&nbsp;kW) at 21,000&nbsp;ft (6,400&nbsp;m); used on [[Supermarine Spitfire (Griffon powered variants)|Spitfire F.Mk.XIV, Mk.21]].
* '''Griffon 65'''
:Similar to Griffon 61 with different propeller reduction gear; Impeller diameters 1st stage: 13.4&nbsp;in (340&nbsp;mm), 2nd stage: 11.3&nbsp;in (290&nbsp;mm);<ref>Flight 1945, p. 315.</ref> used on Spitfire F.Mk.XIV.
* '''Griffon 72'''
:Increased maximum boost pressure to take advantage of 150-[[octane rating|grade]] fuel; 2,245&nbsp;hp (1,675&nbsp;kW) at 9,250&nbsp;ft (2,820&nbsp;m).
* '''Griffon 74'''
:Fuel-injected version of Griffon 72; used on Firefly Mk.IV.
* '''Griffon 83'''
:Modified to drive [[contra-rotating propellers]]; 2,340&nbsp;hp (1,745&nbsp;kW) at 750&nbsp;ft (230&nbsp;m) and 2,100&nbsp;hp (1,565&nbsp;kW) at 12,250&nbsp;ft (3,740&nbsp;m).
* '''Griffon 85'''
:2,375&nbsp;hp (1,770&nbsp;kW); used on [[Supermarine Spiteful|Spiteful Mk.XIV]].
* '''Griffon 89'''
:2,350&nbsp;hp (1,755&nbsp;kW); used on Spiteful Mk.XV.
* '''Griffon 101'''
:2,420&nbsp;hp (1,805&nbsp;kW); Two-stage, three-speed supercharger using Low Supercharger (L.S), Moderate Supercharger (M.S), or Full Supercharger (F.S); reduction gear ratio 4.45; Rolls-Royce fuel injection system.<ref name="Fli46,34."/> Used on Spiteful Mk.XVI.
*'''Griffon 130'''
:2,420&nbsp;hp (1,805&nbsp;kW) at 5,000&nbsp;ft (1,524&nbsp;m) in L.S gear, 2,250&nbsp;hp (1,678&nbsp;kW) at 14,500&nbsp;ft (4,419&nbsp;m) M.S and 2,050&nbsp;hp (1,529&nbsp;kW) at 21,000&nbsp;ft (6,400&nbsp;m) F.S; reduction gear ratio 4.44; modified to drive contra-rotating propellers; Rolls-Royce fuel injection system.<ref name="Fli46,3435."/>
* '''Compound Griffon RGC.30.SM.'''; [[turbo-compound]] engine - cancelled 1949
* '''Turbo Griffon RGT.30.SM.'''; similar to [[Napier Nomad]] - as above{{cn|date=November 2020}}

==Applications==
[[File:Fairey Barracuda Mk III.jpg|thumb|right|Griffon-engined [[Fairey Barracuda]]]]
[[File:25 P 51XR Mustang N6WJ Precious Metal Reno Air Race 2014 photo Don Ramey Logan.jpg|thumb|Griffon engine with contra-rotating propellers on the P 51XR Mustang N6WJ "Precious Metal" 2014 Reno Air Races]]

''Note:''{{#tag:ref|Generic types given only, the Griffon was not the main powerplant for some of these aircraft.|group=nb}}{{#tag:ref|Beaufighter II, Griffon IIB <ref>Lumsden 2003, p.&nbsp;217.</ref>|group=nb}}

* [[Avro Shackleton]]
* [[Blackburn B-54]]
* [[Bristol Beaufighter]]
* [[CAC CA-15]]
* [[Fairey Barracuda]]
* [[Fairey Firefly]]
* [[Folland Fo.108]]
* [[Hawker Sea Fury#Development|Hawker Fury]]<ref>One prototype (LA610) with a Griffon 85 engine and a Rotol six-blade contra-rotating propeller</ref>
* [[Hawker Henley]]<ref>One aircraft as an engine test bed for the Griffon II</ref>
* [[Hawker Tempest|Hawker Tempest Mk III/IV]]
* [[Martin-Baker MB 5]]
* [[Supermarine Seafang]]
* [[Supermarine Seafire]]
* [[Supermarine Seagull (1948)|Supermarine Seagull]]
* [[Supermarine Spiteful]]
* [[Supermarine Spitfire]]

===Racing aircraft===
Several [[North American P-51 Mustang|North American Mustangs]] raced in the Unlimited Class races at the [[Reno Air Races]] have been fitted with Griffons. These include [[Red Baron (aircraft)|''Red Baron'']] (NL7715C), as well as the custom-built P-51XR [[Precious Metal (aircraft)|''Precious Metal'']] (N6WJ) and Mustang/Learjet hybrid ''[[Miss Ashley II]]'' (N57LR).<ref>[http://www.airliners.net/photo/Michelob-Light/North-American-P-51D/1101386/L Picture of the North American P-51D Mustang aircraft] Retrieved 24 September 2011.</ref><ref>[https://web.archive.org/web/20040227093705/http://www.warbirdaeropress.com/articles/PMmods/PMmods.htm Its All in the Details] Retrieved 24 September 2011.</ref><ref>[http://www.airliners.net/photo/Untitled-(Lake-Air)/North-American-P-51D/1123175/L Picture of the North American P-51D Mustang aircraft] Retrieved 24 September 2011.</ref><ref>[http://www.airliners.net/photo/North-American-Rogers-P-51R/0763382/L Picture of the North American/Rogers P-51R aircraft] Retrieved 24 September 2011.</ref> In all cases, Griffons with contra-rotating propellers, taken from [[Avro Shackleton]] patrol bombers were used in these aircraft. The RB51 Red Baron is noteworthy for holding the FAI piston-engine 3-kilometre world speed record from 1979 to 1989 (499.018&nbsp;mph).

===Non-aircraft usage===
The 1980 ''[[Miss Budweiser]]'' [[Hydroplane (boat)|Unlimited Hydroplane]] dominated the race circuit with a Rolls-Royce Griffon engine. It was the last of the competitive piston-engined boats, before [[turboshaft]] powerplants took over.

In modern-day [[tractor pulling]], Griffon engines are also in use, a single or double, rated each at 3,500&nbsp;hp (2,600&nbsp;kW).<ref>{{cite web |url=http://www.greenspirit.info/tractoren.php |title=Green Spirit tractor pulling team |publisher=Greenspirit.info |access-date=2013-01-07 |archive-url=https://web.archive.org/web/20110721203222/http://www.greenspirit.info/tractoren.php |archive-date=21 July 2011 |url-status=dead}}</ref>

==Survivors==
[[File:Shackleton1.jpg|thumb|Avro Shackleton Mk 3 at Ysterplaat AFB in South Africa, serial 1722, a.k.a. Pelican 22. Taken 27 May 2017 at engine run-up. No longer flying but considered mostly airworthy.]]
The Griffon engine continues to be used in restored Fireflies and later mark Spitfires worldwide. The [[Royal Air Force]] [[Battle of Britain Memorial Flight]] is a notable current operator of the Griffon.

The sole remaining technically airworthy Avro Shackleton is based at the [[Air Force Base Ysterplaat]].<ref>[http://www.saafmuseum.co.za/shack.htm SAAF 1722 - Avro Shackleton] {{webarchive|url=https://web.archive.org/web/20090901184539/http://www.saafmuseum.co.za/shack.htm |date=1 September 2009 }} Retrieved: 29 July 2009</ref> However, at least one further airframe is in running condition at the [[Gatwick Aviation Museum]] and another is in running, taxiing condition at [[Coventry Airport]], intended to be flown in a short time.{{citation needed|date=March 2024}}

==Engines on display==
Preserved Griffon engines are on public display at the:
*[[Atlantic Canada Aviation Museum]]
*[[Birmingham Museum Collection Centre]]
*[[Bournemouth Aviation Museum]]
*[[Kissimmee Air Museum]]
*[[Midland Air Museum]]
*[[Rolls-Royce Heritage Trust]], Derby
*[[Royal Air Force Museum London]]
*[[Shuttleworth Collection]]
*[[South African Air Force Museum]], [[AFB Ysterplaat]]
*[[South Yorkshire Aircraft Museum]]
*[[Stonehenge Air Museum]], [[Fortine, Montana]]<ref>{{cite web|url=http://stonehengeairmuseum.org/rolls-royce-griffon-58 |title=ROLLS ROYCE GRIFFON 58 ENGINE|work=stonehengeairmuseum.org|access-date=15 November 2019}}</ref>
*[[Tangmere Military Aviation Museum]]


==Specifications (Griffon 65)==
==Specifications (Griffon 65)==
[[File:RRGriffon.JPG|thumb|right|Side view showing supercharger and carburettor detail]]
{{pistonspecs|
{{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> -->
|<!-- 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 The Aeroplane.''<ref>Lumsden 2003, pp. 216–219.</ref><ref>The Aeroplane 1945, pp. 1–7.</ref>
|type=12-cylinder supercharged liquid-cooled 60° [[V12|Vee]] aircraft piston engine
|type=12-cylinder supercharged liquid-cooled 60° [[V12 engine|Vee]] aircraft piston engine
|bore=6 in (152.4 mm)
|bore={{convert|6|in|mm|1|abbr=on}}
|stroke=6.6 in (167.6 mm)
|stroke={{convert|6.6|in|mm|1|abbr=on}}
|displacement=2,240 in³ (36.75 L)
|displacement={{convert|2240|cid|L|1|abbr=on}}
|length=
|length={{convert|81|in|cm|1|abbr=on}}
|diameter=
|diameter=
|width={{convert|30.3|in|cm|1|abbr=on}}
|width=
|height=
|height={{convert|46|in|cm|1|abbr=on}}
|weight=1,980 lb (900 kg)
|weight={{convert|1980|lb|kg|0|abbr=on}}
|valvetrain=Two intake and two exhaust valves per cylinder with [[sodium]]-cooled exhaust valve stems, actuated via an [[overhead camshaft]].
|valvetrain=Two intake and two exhaust valves per cylinder with [[sodium]]-cooled exhaust valve stems, actuated via an [[overhead camshaft]].
|supercharger=Two-speed two-stage [[centrifugal type supercharger]], boost pressure automatically linked to the throttle, water-air [[intercooler|aftercooler]] installed between the second stage and the engine
|supercharger=Two-speed, two-stage [[centrifugal type supercharger]], boost pressure automatically linked to the throttle, water-air [[intercooler]] installed between the second stage and the engine.
|turbocharger=
|turbocharger=
|fuelsystem=Triple-choke updraft [[carburetor]] with automatic mixture control
|fuelsystem=Triple-choke [[Bendix Corporation|Bendix-Stromberg]] updraught, [[Pressure carburetor|pressure-injection]] [[carburetor|carburettor]] with automatic mixture control
|fueltype= 100 octane (150 octane January to May 1945)
|fueltype=
|oilsystem=[[Dry sump]] with one pressure pump and two scavenge pumps
|oilsystem=[[Dry sump]] with one pressure pump and two scavenge pumps
|coolingsystem=70% water and 30% [[ethylene glycol]] coolant mixture, pressurized
|coolingsystem=70% water and 30% [[ethylene glycol]] coolant mixture, pressurised. Liquid-cooled Intercooler radiator with its own separate system, again using 70/30% water/glycol mix.
|power=<br>
|power=<br />
*2,035 hp (1,520 kW) at 7,000 ft (2,135 m)
*2,035 hp (1,520 kW) at 7,000 ft (2,135 m MS gear),{{#tag:ref|MS and FS refer to the supercharger blower speeds: Moderate/Fully Supercharged.|group=nb}} +18 psi boost pressure at 2,750 rpm
*1,820 hp (1,360 kW) at 21,000 ft (6,400 m)
*2,220 hp (1,655 kW) at 11,000 ft (3,350 m MS gear), +21 psi at 2,750 rpm using 150 octane fuel
*1,820 hp (1,360 kW) at 21,000 ft (6,400 m) at 2,750 rpm
|specpower=0.91 hp/in³ (41.4 kW/L)
|specpower=0.91 hp/in<sup>3</sup> (41.4 kW/L)
|compression=
|compression=6:1
|fuelcon=
|fuelcon=
|specfuelcon=
|specfuelcon=
|oilcon=
|oilcon=
|power/weight=1.03 hp/lb (1.69 kW/kg)
|power/weight=1.03 hp/lb (1.69 kW/kg)
|designer=
|reduction_gear=0.51:1, left-hand tractor
|general_other=
|components_other=
|performance_other=
}}
}}

==See also==
{{aircontent
<!-- other related articles that have not already linked: -->
|see also=
*[[Rolls-Royce R]]
*[[Rolls-Royce aircraft piston engines]]
<!-- designs which were developed into or from this aircraft: -->
|related=

<!-- aircraft that are of similar role, era, and capability 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=
*[[Allison V-1710]]
*[[Daimler-Benz DB 603]]
*[[Daimler-Benz DB 605]]
*[[Junkers Jumo 213]]
*[[Klimov VK-107]]
*[[Mikulin AM-38]]

<!-- See [[WP:Air/PC]] for more explanation of these fields. -->
}}

==Media==
{|
|-
| [[File:GriffonMk58.ogg|thumb|Griffon Mk 58]]
|}


==References==
==References==

* Bridgman, L, (ed.) (1998) ''Jane's fighting aircraft of World War II.'' Crescent. ISBN 0517679647
===Footnotes===
* [[Jeffrey Quill|Quill, J.]] (1983) ''Spitfire - A Test Pilot’s Story.'' Arrow Books. ISBN 0099370204
{{reflist|group=nb}}
* [http://www.spitfiresociety.demon.co.uk/engines.htm <sup>1</sup> Spitfire society]

===Citations===
{{reflist|colwidth=35em}}

===Bibliography===
* Air Ministry. ''Pilot's Notes For Spitfire XIV & XIX; Griffon 65 or 66 Engine''. London: Air Ministry, 1946.
* Bridgman, L, (ed.) (1989) ''Jane's Fighting Aircraft of World War II.'' Crescent. {{ISBN|0-517-67964-7}}
*Carvell, Roger. "Aeroplane Examines the Avro Shackleton." ''[http://www.aeroplanemonthly.co.uk/ Aeroplane]'' No. 2, Vol. 38, Issue 442, February 2010.
*Gunston, Bill. ''World Encyclopedia of Aero Engines: From the Pioneers to the Present Day''. 5th edition, Stroud, UK: Sutton, 2006.{{ISBN|0-7509-4479-X}}
* Lovesey, Cyril. "Development of the Rolls-Royce Merlin from 1939 to 1945". ''Aircraft Engineering'' magazine. London: July 1946
* Lumsden, Alec. ''British Piston Engines and Their Aircraft''. Marlborough, Wiltshire: Airlife Publishing, 2003. {{ISBN|1-85310-294-6}}.
* Price, Alfred. ''The Spitfire Story''. Second edition, London: Arms and Armour Press, 1986. {{ISBN|0-85368-861-3}}.
* Rubbra, A.A. ''Rolls-Royce Piston Aero Engines: A Designer Remembers: Historical Series no 16'' : Rolls-Royce Heritage Trust, 1990. {{ISBN|1-872922-00-7}}
*White, Graham. ''Allied Aircraft Piston Engines of World War II: History and Development of Frontline Aircraft Piston Engines Produced by Great Britain and the United States During World War II''. Warrendale, Pennsylvania: SAE International, 1995. {{ISBN|1-56091-655-9}}
*"A Classic Design; The Rolls-Royce Two-Stage Griffon (article and images)." ''The Aeroplane'', 21 September 1945.
*"[http://www.flightglobal.com/PDFArchive/View/1945/1945%20-%201852.html Rolls-Royce Griffon (65) (article and images).]" ''[[Flight International|Flight and the Aircraft Engineer]]'' No. 1917, Vol. XLVIII, 20 September 1945.
*"[http://www.flightglobal.com/pdfarchive/view/1946/1946%20-%200062.html Rolls-Royce Griffon 130 (article and images).]" ''[[Flight International|Flight and the Aircraft Engineer]]'' No. 1933, Vol. XLIX, 10 January 1946.
* [http://www.flightglobal.com/pdfarchive/view/1956/1956%20-%200578.html British Aero Engines (article and images).]" ''[[Flight International|Flight and the Aircraft Engineer]]'' No. 2468, Vol. 69, 11 May 1956.
*"[http://thunderboats.ning.com/page/1980-u1-miss-budweiser.html 1980 U-1 Miss Budweiser (article).]{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }}" Skid Fin Magazine, 2003, Volume 1 Number 2.

==Further reading==
* [[Jeffrey Quill|Quill, J.]] (1983) ''Spitfire - A Test Pilot’s Story.'' Arrow Books. {{ISBN|0-09-937020-4}}


==External links==
==External links==
{{Commons category}}
*[http://www.spitfiresociety.demon.co.uk/engines.htm The Spitfire Engines- Rolls-Royce Merlin and Griffon]


*[https://www.youtube.com/watch?v=QdfO657zHNY Griffon 58 on YouTube]
{{airlistbox}}
*[http://www.flightglobal.com/pdfarchive/view/1945/1945%20-%201852.html "Rolls-Royce Griffon (65)"] a 1945 [[Flight International|''Flight'']] article on the Griffon 65
*[http://www.spitfireperformance.com/griffon-65.pdf "Rolls-Royce Griffon (65)"] a 1945 ''Flight'' article on the Griffon 65
*[http://www.flightglobal.com/pdfarchive/view/1946/1946%20-%200062.html "Rolls-Royce Griffon 130"] a 1946 ''Flight'' article


{{RRaeroengines}}
[[Category:Rolls-Royce aircraft piston engines|Griffon]]


[[it:Rolls Royce Griffon]]
[[Category:Rolls-Royce aircraft piston engines|Griffon]]
[[Category:1930s aircraft piston engines]]
[[Category:Articles containing video clips]]
[[Category:V12 aircraft engines]]

Latest revision as of 15:40, 16 December 2024

Griffon
Preserved Rolls-Royce Griffon with cutaway sections.
Type Liquid-cooled V-12 four-stroke piston aero engine
Manufacturer Rolls-Royce
First run November 1939
Major applications Avro Shackleton
Fairey Firefly
Supermarine Spitfire
Number built 8,108

The Rolls-Royce Griffon is a British 37-litre (2,240 cu in) capacity, 60-degree V-12, liquid-cooled aero engine designed and built by Rolls-Royce Limited. In keeping with company convention, the Griffon was named after a bird of prey, in this case the griffon vulture.

Design work on the Griffon started in 1938 at the request of the Fleet Air Arm, for use in new aircraft designs such as the Fairey Firefly. In 1939 it was also decided that the engine could be adapted for use in the Spitfire. Development was stopped temporarily to concentrate efforts on the smaller Merlin and the 24-cylinder Vulture; the engine did not go into production until the early 1940s.

The Griffon was the last in the line of V-12 aero engines to be produced by Rolls-Royce with production ceasing in 1955. Griffon engines remain in Royal Air Force service today with the Battle of Britain Memorial Flight.

Design and development

[edit]

Origins

[edit]
The first Griffon-powered Spitfire IV, DP845

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,[1] which was never flown, was used for "Moderately Supercharged Buzzard development" (which was not proceeded with until much later), and bore no direct relationship to the volume-produced Griffon of the 1940s.

In 1938, the Fleet Air Arm approached Rolls-Royce and asked whether a larger version of the Merlin could be designed. The requirements were that the new engine have good power at low altitude and that it be reliable and easy to service.[2] Work began on the design of the engine soon afterwards.[nb 1] The design process was relatively smooth compared with that of the Merlin, and the first of three prototype Griffon Is first ran in the Experimental Department on 30 November 1939.[3][4]

Although the Griffon was designed for naval aircraft, on 8 November 1939 N E Rowe of the Air Ministry suggested fitting the Griffon in a Spitfire. Three weeks later, permission was given to Supermarine to explore the possibilities of adapting the Griffon to the Spitfire; in response, Supermarine issued 'Specification 466' on 4 December. This decision led to a change in the disposition of the engine accessories to reduce the frontal area of the engine as much as possible.[4] As a result, the frontal area of the bare Griffon engine was 7.9 square feet (0.73 m2) compared with 7.5 square feet (0.70 m2) of the Merlin, despite the Griffon's much larger capacity.[5] This redesigned engine first ran on 26 June 1940 and went into production as the Griffon II.

In early 1940, with the expected Battle of Britain looming, on the orders of Lord Beaverbrook, Minister of Aircraft Production, work on the new engine had been halted temporarily to concentrate on the smaller 27 L (1,650 cu in) Merlin which had already surpassed the output achieved with the early Griffon.

Design

[edit]
A Griffon installed on WH632, an airworthy Fairey Firefly at the Canadian Warplane Heritage Museum (2014)

Compared with earlier Rolls-Royce designs, the Griffon engine featured several improvements, which meant that it was physically only slightly larger than the Merlin, in spite of its 36% larger capacity of 37-litres (2,240 cu in).[2]

One significant difference was the incorporation of the camshaft and magneto drives into the propeller reduction gears at the front of the engine, rather than using a separate system of gears driven from the back end of the crankshaft; this allowed the overall length of the engine to be reduced as well as making the drive train more reliable and efficient.[6][nb 2] The drive for the supercharger was also taken from the front of the engine, which required a long shaft to run to its location at the back of the engine.[7]

The Merlin engine's crankshaft lubrication was via a gallery cut into the engine block to feed each main bearing and then onto a secondary adjacent big end bearing via a gallery in the crankshaft itself. The crankpin was second in line to the main bearing in oil flow and pressure, with oil having to flow through the main bearing first. The Griffon improved on this arrangement being the first Rolls-Royce production aero engine to use a hollow crankshaft as the means of lubricating the main and big end bearings, with oil being fed from each end of the crankshaft giving even flow to all bearings.[6][8]

In another change from convention, one high efficiency B.T.H-manufactured dual magneto was mounted on top of the propeller reduction casing;[9] earlier Rolls-Royce designs using twin magnetos mounted at the rear of the engine.[10]

The Griffon 61 series introduced a two-stage supercharger and other design changes: the pressure oil pumps were now housed internally within the sump and an effort was made to remove as many external pipes as possible.[11] In addition, the drive for the supercharger was moved to the crankshaft at the back of the engine, via a short torsion shaft, rather than at the front of the engine, using a long drive shaft as used by earlier Griffon variants.[7]

Production of the aero version of the Griffon ended in December 1955, while a marine version, the Sea Griffon, continued to be produced for the RAF's High Speed Launches.[12]

Basic component overview (Griffon 65)

[edit]

From Jane's and Flight.[13][14]

Griffon, cut away to show camshaft drives etc., at the Battle of Britain Museum at RAF Coningsby
Cylinders
Twelve cylinders consisting of high-carbon steel, floating wet liners[15] set in two, two-piece cylinder blocks of cast aluminium alloy having separate heads and skirts. Cylinder liners chromium plated in the bores for 2.5 in (64 mm) from the head.[15] Cylinder blocks mounted with an included 60-degree angle onto inclined upper faces of a two-piece crankcase. Cylinder heads fitted with cast-iron inlet valve guides, phosphor bronze exhaust valve guides, and renewable "Silchrome" steel-alloy valve seats. Two diametrically opposed spark plugs protrude into each combustion chamber.
Pistons
Machined from "R.R.59" alloy forgings. Fully floating gudgeon pins of hardened nickel-chrome steel. Two compression and one drilled oil-control ring above the gudgeon pin, and another drilled oil-control ring below.
Connecting rods
H-section machined nickel-steel forgings, each pair consisting of a plain and a forked rod. The forked rod carries a nickel-steel bearing block which accommodates steel-backed lead-bronze-alloy bearing shells. The "small-end" of each rod houses a floating phosphor bronze bush.
Crankshaft
One-piece, machined from a nitrogen-hardened nickel-chrome molybdenum steel forging. Statically and dynamically balanced. Seven main bearings and six throws. Internal oilway, with feed from both ends, used to distribute lubricants to main and big end bearings.[6] "Floating" front end bearing consisting of an internally toothed annulus bolted to crankshaft, meshing with and incorporating a semi-floating ring, internally splined to a short coupling shaft. Coupling shaft splined at front end to driving wheel of propeller reduction gear.[6] Clockwise rotation when viewed from rear.
Crankcase
Two aluminium-alloy castings joined together on the horizontal centreline. The upper portion bears the wheelcase, cylinder blocks and part of the housing for the airscrew reduction gear; and carries the crankshaft main bearings (split mild-steel shells lined with lead–bronze alloy). The lower half forms an oil sump and carries the main pressure oil pump, supercharger change-speed operating pump and two scavenge pumps. It also houses the main coolant pump which is driven through the same gear-train as the oil pumps.
Wheelcase
Aluminium-alloy casting fitted to rear of crankcase. Carries the supercharger; and houses drives to the supercharger, auxiliary gearbox coupling, engine speed indicator, airscrew constant-speed unit, intercooler pump and fuel pump, as well as the oil and coolant pumps in the lower half crankcase.
Valve gear
Two inlet and two exhaust poppet valves of "K.E.965" austenitic nickel-chrome steel per cylinder. Exhaust valves have sodium-cooled stems. "Brightray" (nickel-chromium) protective coating to the whole of the combustion face and seat of the exhaust valves, and to the seat only of the inlet valves. Each valve is held closed by a pair of concentric coil springs. A single, seven-bearing camshaft, located centrally on the top of each cylinder head operates 24 individual steel rockers; 12 pivoting from a rocker shaft on the inner, intake side of the block to actuate the exhaust valves, the others pivoting from a shaft on the exhaust side of the block to actuate the inlet valves.

Engine capacity, mass flow, and supercharging

[edit]

Although it is common practice to compare different piston engines and their performance potential by referring to the engine displacement or swept volume, this does not give an accurate reading of an engine's capabilities. According to A C Lovesey, who was in charge of the Merlin's development,[nb 3] "The impression still prevails that the static capacity known as the swept volume is the basis of comparison of the possible power output for different types of engine, but this is not the case because the output of the engine depends solely on the mass of air it can be made to consume efficiently, and in this respect the supercharger plays the most important role."[16]

Unlike the Merlin, the Griffon was designed from the outset to use a single-stage supercharger driven by a two-speed, hydraulically operated gearbox; the initial production versions, the Griffon II, III, IV, and VI series, were designed to give their maximum power at low altitudes and were mainly used by the Fleet Air Arm. The Griffon 60, 70, and 80 series featured two-stage supercharging and achieved their maximum power at low to medium altitudes. The Griffon 101, 121, and 130 series engines, collectively designated Griffon 3 SML,[17] used a two-stage, three-speed supercharger, adding a set of "Low Supercharger (L.S)" gears to the already existing Medium and Full Supercharger (M.S and F.S) gears.[17] Another modification was to increase the diameters of both impellers, thus increasing the rated altitudes at which maximum power could be generated in each gear.[18] While the 101 continued to drive a five-blade propeller, the 121 and 130 series were designed to drive contra-rotating propellers.[17] In 1946 a Griffon 101 was fitted to the Supermarine Spiteful XVI, RB518 (a re-engined production Mk.XIV); this aircraft achieved a maximum speed of 494 mph (795 km/h) with full military equipment.[19]

Pilot transition

[edit]

Pilots who converted from the Merlin to the Griffon-engined Spitfires soon discovered that, because the Griffon engine's propeller rotated in the opposite direction to that of the Merlin, the fighter swung to the right on takeoff rather than to the left.[20][nb 4] This tendency was even more marked with the more powerful 60- and 80-series Griffon engines, with their five-bladed propellers. As a result, pilots had to learn to apply left (port) trim on takeoff, instead of the right (starboard) trim they were used to applying.[21] On takeoff, the throttle had to be opened slowly, as the pronounced swing to the right could lead to "crabbing" and severe tyre wear.[22]

Some test Spitfire XIVs, 21s, and 24s were fitted with contra-rotating propellers, which eliminated the torque effect. Early problems with the complex gearbox that was required for contra-rotating propellers prevented them from ever becoming operational in Spitfires, but they were used on later aircraft, including the Seafire FR. Mk 46 and F and FR.47, which were fitted with Griffon 87s driving contra-rotating propellers as standard equipment.[23] The Griffon 57 and 57A series, installed in Universal Power Plant (UPP) installations and driving contra-rotating propellers, was used in the Avro Shackleton maritime patrol aircraft.[24]

Variants

[edit]

The Griffon was produced in approximately 50 different variants, the Griffon 130 being the last in the series. Details of representative variants are listed below:

  • Griffon IIB
1,730 hp (1,290 kW) at 750 ft (230 m) and 1,490 hp (1,110 kW) at 14,000 ft (4,270 m); Single-stage two-speed supercharger; impeller diameter 10 in (254 mm); gear ratios 7.85:1, 10.68:1.[20] Used on Firefly Mk.I and Spitfire XII.
  • Griffon VI
Increased maximum boost pressure, 1,850 hp (1,380 kW) at 2,000 ft (610 m); impeller diameter 9.75 in (247 mm).[20] Used on Seafire Mk.XV and Mk. XVII, Spitfire XII.
A Rolls-Royce Griffon 58 displayed at the Shuttleworth Collection (2008)
  • Griffon 57 and 57A
1,960 hp (1,460 kW); 2,345 hp (1,749 kW) with water-methanol injection on take-off: used on Avro Shackleton.[24]
  • Griffon 61
Introduced a two-speed two-stage supercharger with aftercooler similar to that on Merlin 61; 2,035 hp (1,520 kW) at 7,000 ft (2,100 m) and 1,820 hp (1,360 kW) at 21,000 ft (6,400 m); used on Spitfire F.Mk.XIV, Mk.21.
  • Griffon 65
Similar to Griffon 61 with different propeller reduction gear; Impeller diameters 1st stage: 13.4 in (340 mm), 2nd stage: 11.3 in (290 mm);[25] used on Spitfire F.Mk.XIV.
  • Griffon 72
Increased maximum boost pressure to take advantage of 150-grade fuel; 2,245 hp (1,675 kW) at 9,250 ft (2,820 m).
  • Griffon 74
Fuel-injected version of Griffon 72; used on Firefly Mk.IV.
  • Griffon 83
Modified to drive contra-rotating propellers; 2,340 hp (1,745 kW) at 750 ft (230 m) and 2,100 hp (1,565 kW) at 12,250 ft (3,740 m).
  • Griffon 85
2,375 hp (1,770 kW); used on Spiteful Mk.XIV.
  • Griffon 89
2,350 hp (1,755 kW); used on Spiteful Mk.XV.
  • Griffon 101
2,420 hp (1,805 kW); Two-stage, three-speed supercharger using Low Supercharger (L.S), Moderate Supercharger (M.S), or Full Supercharger (F.S); reduction gear ratio 4.45; Rolls-Royce fuel injection system.[17] Used on Spiteful Mk.XVI.
  • Griffon 130
2,420 hp (1,805 kW) at 5,000 ft (1,524 m) in L.S gear, 2,250 hp (1,678 kW) at 14,500 ft (4,419 m) M.S and 2,050 hp (1,529 kW) at 21,000 ft (6,400 m) F.S; reduction gear ratio 4.44; modified to drive contra-rotating propellers; Rolls-Royce fuel injection system.[18]

Applications

[edit]
Griffon-engined Fairey Barracuda
Griffon engine with contra-rotating propellers on the P 51XR Mustang N6WJ "Precious Metal" 2014 Reno Air Races

Note:[nb 5][nb 6]

Racing aircraft

[edit]

Several North American Mustangs raced in the Unlimited Class races at the Reno Air Races have been fitted with Griffons. These include Red Baron (NL7715C), as well as the custom-built P-51XR Precious Metal (N6WJ) and Mustang/Learjet hybrid Miss Ashley II (N57LR).[29][30][31][32] In all cases, Griffons with contra-rotating propellers, taken from Avro Shackleton patrol bombers were used in these aircraft. The RB51 Red Baron is noteworthy for holding the FAI piston-engine 3-kilometre world speed record from 1979 to 1989 (499.018 mph).

Non-aircraft usage

[edit]

The 1980 Miss Budweiser Unlimited Hydroplane dominated the race circuit with a Rolls-Royce Griffon engine. It was the last of the competitive piston-engined boats, before turboshaft powerplants took over.

In modern-day tractor pulling, Griffon engines are also in use, a single or double, rated each at 3,500 hp (2,600 kW).[33]

Survivors

[edit]
Avro Shackleton Mk 3 at Ysterplaat AFB in South Africa, serial 1722, a.k.a. Pelican 22. Taken 27 May 2017 at engine run-up. No longer flying but considered mostly airworthy.

The Griffon engine continues to be used in restored Fireflies and later mark Spitfires worldwide. The Royal Air Force Battle of Britain Memorial Flight is a notable current operator of the Griffon.

The sole remaining technically airworthy Avro Shackleton is based at the Air Force Base Ysterplaat.[34] However, at least one further airframe is in running condition at the Gatwick Aviation Museum and another is in running, taxiing condition at Coventry Airport, intended to be flown in a short time.[citation needed]

Engines on display

[edit]

Preserved Griffon engines are on public display at the:

Specifications (Griffon 65)

[edit]
Side view showing supercharger and carburettor detail

Data from Lumsden and The Aeroplane.[36][37]

General characteristics

  • Type: 12-cylinder supercharged liquid-cooled 60° Vee aircraft piston engine
  • Bore: 6 in (152.4 mm)
  • Stroke: 6.6 in (167.6 mm)
  • Displacement: 2,240 cu in (36.7 L)
  • Length: 81 in (205.7 cm)
  • Width: 30.3 in (77.0 cm)
  • Height: 46 in (116.8 cm)
  • Dry weight: 1,980 lb (898 kg)

Components

Performance

  • Power output:
  • 2,035 hp (1,520 kW) at 7,000 ft (2,135 m MS gear),[nb 7] +18 psi boost pressure at 2,750 rpm
  • 2,220 hp (1,655 kW) at 11,000 ft (3,350 m MS gear), +21 psi at 2,750 rpm using 150 octane fuel
  • 1,820 hp (1,360 kW) at 21,000 ft (6,400 m) at 2,750 rpm
  • Specific power: 0.91 hp/in3 (41.4 kW/L)
  • Compression ratio: 6:1
  • Power-to-weight ratio: 1.03 hp/lb (1.69 kW/kg)

See also

[edit]

Comparable engines

Related lists

Media

[edit]
Griffon Mk 58

References

[edit]

Footnotes

[edit]
  1. ^ Although the Griffon from 1933 shared the R engine's bore and stroke with the Griffon I of 1939, the Griffon I was a completely new design.[2]
  2. ^ Incorporating four sets of gears (two camshaft drives, plus propeller reduction gears and magneto drive) into one unit meant that the extra group of gears for the magnetos and camshafts, which were normally mounted at the rear of the crankshaft, could be omitted.
  3. ^ After helping design the two-stage, two-speed supercharger for the Merlin Lovesey went on to help develop the Rolls-Royce jet engines; although the quote refers to the Merlin it applies equally as well to the Griffon.
  4. ^ The propeller of the Griffon rotated to the left (counter-clockwise) when viewed from the cockpit.
  5. ^ Generic types given only, the Griffon was not the main powerplant for some of these aircraft.
  6. ^ Beaufighter II, Griffon IIB [26]
  7. ^ MS and FS refer to the supercharger blower speeds: Moderate/Fully Supercharged.

Citations

[edit]
  1. ^ Eves 2001, p. 228.
  2. ^ a b c Flight 1945, p. 309.
  3. ^ Lumsden 2003, p. 216.
  4. ^ a b Morgan and Shacklady 2000, p. 133.
  5. ^ Morgan and Shacklady 2000, p. 134.
  6. ^ a b c d Flight 1945, p. 312.
  7. ^ a b The Aeroplane 1945, pp. 1, 3, 6.
  8. ^ "Rolls-Royce Griffon Engine".
  9. ^ Flight 1945, pp. 312, 314.
  10. ^ Rubbra 1990, p. 118.
  11. ^ The Aeroplane 1945, pp. 1, 8.
  12. ^ Flight 1956, p. 578.
  13. ^ Bridgman 1989, pp. 279–280.
  14. ^ [Staff author] 20 September 1945. "The Rolls-Royce Griffon" Flight, pp. 309–316. www.flightglobal.com. Retrieved: 29 October 2009.
  15. ^ a b Flight 1945, p. 313.
  16. ^ Lovesey 1946, p. 218.
  17. ^ a b c d Flight 1946, p. 34.
  18. ^ a b Flight 1946, pp. 34–35.
  19. ^ Morgan and Shacklady 2000, pp. 501, 503.
  20. ^ a b c Lumsden 2003, p. 217.
  21. ^ Price 1995, pp. 29, 32–33.
  22. ^ Air Ministry 1946, paragraph 49 (i), pp. 26–27
  23. ^ Morgan and Shacklady 2000, pp. 573, 579, 580.
  24. ^ a b Carvell 2010, p. 57.
  25. ^ Flight 1945, p. 315.
  26. ^ Lumsden 2003, p. 217.
  27. ^ One prototype (LA610) with a Griffon 85 engine and a Rotol six-blade contra-rotating propeller
  28. ^ One aircraft as an engine test bed for the Griffon II
  29. ^ Picture of the North American P-51D Mustang aircraft Retrieved 24 September 2011.
  30. ^ Its All in the Details Retrieved 24 September 2011.
  31. ^ Picture of the North American P-51D Mustang aircraft Retrieved 24 September 2011.
  32. ^ Picture of the North American/Rogers P-51R aircraft Retrieved 24 September 2011.
  33. ^ "Green Spirit tractor pulling team". Greenspirit.info. Archived from the original on 21 July 2011. Retrieved 7 January 2013.
  34. ^ SAAF 1722 - Avro Shackleton Archived 1 September 2009 at the Wayback Machine Retrieved: 29 July 2009
  35. ^ "ROLLS ROYCE GRIFFON 58 ENGINE". stonehengeairmuseum.org. Retrieved 15 November 2019.
  36. ^ Lumsden 2003, pp. 216–219.
  37. ^ The Aeroplane 1945, pp. 1–7.

Bibliography

[edit]

Further reading

[edit]
[edit]
Wikimedia Commons has media related to Rolls-Royce Griffon.
Retrieved from "https://en.wikipedia.org/enwiki/w/index.php?title=Rolls-Royce_Griffon&oldid=1263421917"