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101-531: In the late 1920s Harry Ricardo wrote a paper on the sleeve valve design that led to the USAAC's hyper engine efforts. He claimed that the 1 hp/in³ goal was impossible to achieve with poppet valve type engines. The USAAC engineering team at Wright Field decided to test this claim by beating it. The I-1430 was the result of an experimental effort at Wright Field to build a high-power cylinder using conventional poppet valves . The engineers, led by Sam Heron, used

202-509: A Sephardi Jew of Portuguese origin. He was one of the first people in England to see an automobile when his grandfather purchased one in 1898. He was from a relatively wealthy family and educated at Rugby School . In October 1903 he matriculated at Trinity College, Cambridge as a civil engineering student. Ricardo had been using tools and building engines since the age of ten. In 1911 Ricardo married Beatrice Bertha Hale, an art student at

303-467: A tour de force in the 1922 RAC T. T. O Payne in the Ricardo Vauxhall came 3rd, Jean Chassagne on a 1921 Grand Prix Sunbeam winning outright. The engine was later developed by Mays and Villiers , who fitted a supercharger, and was still a winner fifteen years later. In 1922 and 1923 Ricardo published a two-volume work "The Internal Combustion Engine". Although Ricardo did not invent

404-479: A "universal" propeller shaft, allowing either de Havilland or Rotol manufactured propellers to be used. The first major version to incorporate changes brought about through experience in operational service was the XX, which was designed to run on 100- octane fuel. This fuel allowed higher manifold pressures , which were achieved by increasing the boost from the centrifugal supercharger . The Merlin XX also utilised

505-940: A Merlin X with a two-speed supercharger in high gear generated 1,150 hp (860 kW) at 15,400 feet (4,700 m) and 1,160 hp (870 kW) at 16,730 feet (5,100 m). From late 1939, 100-octane fuel became available from the U.S., West Indies , Persia , and, in smaller quantities, domestically, consequently, "... in the first half of 1940 the RAF transferred all Hurricane and Spitfire squadrons to 100 octane fuel." Small modifications were made to Merlin II and III series engines, allowing an increased (emergency) boost pressure of +12 pounds per square inch (183 kPa; 1.85 atm). At this power setting these engines were able to produce 1,310 hp (980 kW) at 9,000 ft (2,700 m) while running at 3,000 revolutions per minute. Increased boost could be used indefinitely as there

606-621: A build-up of lead in the combustion chambers, causing excessive fouling of the spark plugs . Better results were achieved by adding 2.5% mono methyl aniline (M.M.A.) to 100-octane fuel. The new fuel allowed the five-minute boost rating of the Merlin 66 to be raised to +25 pounds per square inch (272 kPa; 2.7 atm). With this boost rating the Merlin 66 generated 2,000 hp (1,500 kW) at sea level and 1,860 hp (1,390 kW) at 10,500 ft (3,200 m). Starting in March 1944,

707-523: A hand in the design of the Vauxhall engine designed by Laurence Pomeroy for the RAC 2,000 miles (3,200 km) trial of 1908. Before graduation, Ricardo designed a two-stroke motorcycle engine to study the effect of mixture strength upon the combustion process. When he graduated, the small firm of Messrs Lloyd and Plaister expressed interest in making the engine. Ricardo produced designs for two sizes, and

808-461: A higher altitude of over 19,000 ft (5,800 m); and also improved the design of both the impeller, and the diffuser which controlled the airflow to it. These modifications led to the development of the single-stage Merlin XX and 45 series. A significant advance in supercharger design was the incorporation in 1938 of a two-speed drive (designed by the French company Farman ) to the impeller of

909-520: A new 1,100 hp (820 kW)-class design known as the PV-12, with PV standing for Private Venture, 12-cylinder , as the company received no government funding for work on the project. The PV-12 was first run on 15 October 1933 and first flew in a Hawker Hart biplane ( serial number K3036 ) on 21 February 1935. The engine was originally designed to use the evaporative cooling system then in vogue. This proved unreliable and when ethylene glycol from

1010-455: A new six-cylinder engine with reduced smoke emissions, which was also much more powerful, and still fit into the same space as the existing one. It produced 150 hp (110 kW), compared with 105 hp (78 kW), and later modifications produced 225 hp (168 kW) and 260 hp (190 kW) By April 1917 one hundred engines were being produced a week. A total of over 8,000 engines were put into military service, powering all of

1111-493: A problem after some months due to the physical and mental effects of wartime conditions such as the frequent occupation of air-raid shelters . It was agreed to cut the punishing working hours slightly to 82 hours a week, with one half-Sunday per month awarded as holiday. Record production is reported to have been 100 engines in one day. Immediately after the war the site repaired and overhauled Merlin and Griffon engines, and continued to manufacture spare parts. Finally, following

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1212-500: A single cylinder, and was the heaviest entered, but his motorcycle design won the competition, having covered a distance of 40 miles (64 km). He was then persuaded to join Bertram Hopkinson , Professor of Mechanism and Applied Mechanics, researching engine performance. He graduated in 1906 and spent another year researching at Cambridge. Ricardo is said by Percy Kidner, then co-managing director of Vauxhall, to have had

1313-472: A variety of techniques to raise the allowable RPM, which was the key to increased power without requiring a larger engine. The USAAC was interested in very large bomber designs, and in engines that could be buried in the wings in order to improve streamlining. From this requirement they designed a 12-cylinder horizontally opposed engine using twelve separate "hyper" cylinders. Although this sort of arrangement, with entirely separate cylinders from each other and

1414-495: 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 ... the engine has to be capable of dealing with the greater mass flows with respect to cooling, freedom from detonation and capable of withstanding high gas and inertia loads ... During the course of research and development on superchargers it became apparent to us that any further increase in

1515-677: The Air Ministry had provided a total of £1,927,000 by December 1939. Having a workforce that consisted mainly of design engineers and highly skilled men, the Derby factory carried out the majority of development work on the Merlin, with flight testing carried out at nearby RAF Hucknall . All the Merlin-engined aircraft taking part in the Battle of Britain had their engines assembled in the Derby factory. Total Merlin production at Derby

1616-457: The Air Ministry , the Ministry of Aircraft Production and local authority officials. Hives was an advocate of shadow factories , and, sensing the imminent outbreak of war, pressed ahead with plans to produce the Merlin in sufficient numbers for the rapidly expanding Royal Air Force. Despite the importance of uninterrupted production, several factories were affected by industrial action . By

1717-473: The Battle of Britain Memorial Flight , and power many restored aircraft in private ownership worldwide. In the early 1930s, Rolls-Royce started planning its future aero-engine development programme and realised there was a need for an engine larger than their 21-litre (1,296 cu in) Kestrel , which was being used with great success in a number of 1930s aircraft. Consequently, work was started on

1818-733: The British heavy tanks of the First World War since the Mark V. In addition, several hundred of the 150 hp (110 kW) engines were also used in France for providing power and light to base workshops, hospitals, camps, etc. In 1917 his old mentor, Bertram Hopkinson , who was now Technical Director at the Air Ministry , invited Ricardo to join the new engine research facility at the Department of Military Aeronautics, later to become

1919-828: The Centaurus , Napier produced the Napier Sabre , and Rolls-Royce produced the Eagle and Crecy , all using sleeve valves. In 1929 Ricardo was elected Fellow of the Royal Society . Ricardo's work on the sleeve valve affected the development of British aircraft engines in the thirties and during the war. He enhanced the Rolls-Royce Merlin engine in the Mosquito by giving it an oxygen enrichment system to improve its performance. Ricardo also assisted in

2020-512: The RAE . In 1918 Hopkinson was killed while flying a Bristol Fighter , and Ricardo took over his position. From that point on the department produced a string of experimental engines and research reports that constantly drove the British, and world, engine industry. One of Ricardo's first major research projects was on the problems of irregular combustion , known as knocking or pinging . To study

2121-610: The Second Tactical Air Force (2TAF) also began using 100/150 grade fuel. This fuel was also offered to the USAAF where it was designated "PPF 44-1" and informally known as "Pep". Production of the Rolls-Royce Merlin was driven by the forethought and determination of Ernest Hives , who at times was enraged by the apparent complacency and lack of urgency encountered in his frequent correspondence with

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2222-776: The Slade School of Art , in London. Her father, Charles Bowdich Hale, was the Ricardos' family doctor. They had three daughters, and lived most of their married life at Lancing and Edburton in West Sussex . In 1904, at the end of his first year at Cambridge, Ricardo decided to enter the University Automobile Club's event, which was a competition to design a machine that could travel the furthest on 1 imperial quart (1.14 L ) of petrol. His engine had

2323-601: The Supermarine Spitfire and the Hawker Hurricane ; the latter designed in response to another specification, F36/34. Both were designed around the PV-12 instead of the Kestrel, and were the only contemporary British fighters to have been so developed. Production contracts for both aircraft were placed in 1936, and development of the PV-12 was given top priority as well as government funding. Following

2424-780: The XI-1430 to indicate the purely experimental use. A 24-cylinder H-style engine, the XH-2860, based on the XI-1430 was designed but probably not built. Data from Aircraft Engines of the World 1946 Comparable engines Related lists Wilkinson, Paul H. (1946). Aircraft Engines of the World 1946 . London: Sir isaac Pitman & Sons Ltd. Harry Ricardo Citroen Rosalie diesel engine Turbulent Head gasoline combustion system Comet diesel combustion system Sir Harry Ralph Ricardo (26 January 1885 – 18 May 1974)

2525-481: The sleeve valve , in 1927, he produced a seminal research paper that outlined the advantages of the sleeve valve, and suggested that poppet valve engines would not be able to offer power outputs much beyond 1500 hp (1,100 kW). A number of sleeve valve aircraft engines were developed following this paper, notably by Napier , Bristol and Rolls-Royce . Bristol produced the Perseus , Hercules , Taurus and

2626-503: The time between overhauls (TBO) was typically 650–800 hours depending on use. By then single-stage engines had accumulated 2,615,000 engine hours in civil operation, and two-stage engines 1,169,000. In addition, an exhaust system to reduce noise levels to below those from ejector exhausts was devised for the North Star/Argonaut. This "cross-over" system took the exhaust flow from the inboard bank of cylinders up-and-over

2727-526: The 1,700 hp (1,300 kW) 42-litre (2,560 cu in) Rolls-Royce Vulture used four Kestrel-sized cylinder blocks fitted to a single crankcase and driving a common crankshaft, forming an X-24 layout. This was to be used in larger aircraft such as the Avro Manchester . Although the Peregrine appeared to be a satisfactory design, it was never allowed to mature since Rolls-Royce's priority

2828-727: The Army turned its attention to new pursuit models. For this role the O-1430 was not terribly useful, so Continental modified the basic design into a V-12, and then into an inverted-V-12, the I-1430 . The I-1430 featured cylinders with "hemispherical" combustion chambers and, like the 1936-designed Junkers Jumo 211 inverted V12 German aviation powerplant, using twin exhaust valves, with the I-1430 adding sodium-filled exhaust valves in its own multi-valve design. Although it retained separate cylinders,

2929-569: The Bentley marque and the factory. Today it is known as Bentley Crewe. Hives further recommended that a factory be built near Glasgow to take advantage of the abundant local work force and the supply of steel and forgings from Scottish manufacturers. In September 1939, the Air Ministry allocated £4,500,000 for a new Shadow factory. This government -funded and -operated factory was built at Hillington starting in June 1939 with workers moving into

3030-476: The British Mark V . The Daimler sleeve-valve engine used in the Mark I created copious amounts of smoke, which easily gave away its position. Ricardo was asked to look at the problem of reducing smoky exhaust gases and decided that a new engine was needed. Existing companies were able to fulfill the construction of such an engine but not the design, so Ricardo set himself to the task. He succeeded in designing

3131-578: The Continental I-1430 in 1943. During development, interest in the "buried engine" concept faded. Improvements in conventional streamlining, notably the NACA cowling , eliminated the need for a buried engine for improved performance. Additionally, with bomber designs like the B-17 , using radial engines for power, starting to enter production, the need for new bomber designs became less pressing and

Continental XI-1430 - Misplaced Pages Continue

3232-471: The Diesel "Comet" Swirl chamber that made high-speed diesel engines economically feasible. Harry Ricardo was born at 13 Bedford Square, London, in 1885, the eldest of three children, and only son of Halsey Ricardo , the architect, and his wife Catherine Jane, daughter of Sir Alexander Meadows Rendel , a civil engineer. Ricardo was descended from a brother of the famous political economist David Ricardo ,

3333-421: The Merlin 130/131 versions specifically designed for the de Havilland Hornet . Ultimately, during tests conducted by Rolls-Royce at Derby , an RM.17.SM (the high altitude version of the Merlin 100-Series) achieved 2,640 hp (1,970 kW) at 36 lb boost (103"Hg) on 150-octane fuel with water injection. With the end of the war, work on improving Merlin power output was halted and the development effort

3434-462: The Merlin 60 series gained 300 hp (220 kW) at 30,000 ft (9,100 m) over the Merlin 45 series, at which altitude a Spitfire IX was nearly 70 mph (110 km/h) faster than a Spitfire V. The two-stage Merlin family was extended in 1943 with the Merlin 66, which had its supercharger geared for increased power ratings at low altitudes, and the Merlin 70 series that were designed to deliver increased power at high altitudes. While

3535-476: The Merlin 66-powered Spitfire IXs of two Air Defence of Great Britain (ADGB) squadrons were cleared to use the new fuel for operational trials, and it was put to good use in the summer of 1944 when it enabled Spitfire L.F. Mk. IXs to intercept V-1 flying bombs coming in at low altitudes. 100/150 grade fuel was also used by Mosquito night fighters of the ADGB to intercept V-1s. In early February 1945, Spitfires of

3636-408: The Merlin X. The later Merlin XX incorporated the two-speed drive as well as several improvements that enabled the production rate of Merlins to be increased. The low-ratio gear, which operated from takeoff to an altitude of 10,000 ft (3,000 m), drove the impeller at 21,597 rpm and developed 1,240 hp (920 kW) at that height; while the high gear's (25,148 rpm) power rating

3737-553: The Merlin ran only on 100-octane fuel, and the five-minute combat limitation was raised to +18 pounds per square inch (224 kPa; 2.3 atm). In late 1943 trials were run of a new "100/150" grade (150-octane) fuel, recognised by its bright-green colour and "awful smell". Initial tests were conducted using 6.5 cubic centimetres (0.23  imp fl oz ) of tetraethyllead (T.E.L.) for every one imperial gallon of 100-octane fuel (or 1.43 cc/L or 0.18 U.S. fl oz/U.S. gal), but this mixture resulted in

3838-606: The Merlin was largely superseded by the Rolls-Royce Griffon for military use, with most Merlin variants being designed and built for airliners and military transport aircraft . The Packard V-1650 was a version of the Merlin built in the United States. Production ceased in 1950 after a total of almost 150,000 engines had been delivered. Merlin engines remain in Royal Air Force service today with

3939-521: The Merlin's components itself. Hillingdon required "a great deal of attention from Hives" from when it was producing its first complete engine; it had the highest proportion of unskilled workers in any Rolls-Royce-managed factory”. Engines began to leave the production line in November 1940, and by June 1941 monthly output had reached 200, increasing to more than 400 per month by March 1942. In total 23,675 engines were produced. Worker absenteeism became

4040-425: The Merlin's technical improvements resulted from more efficient superchargers , designed by Stanley Hooker , and the introduction of aviation fuel with increased octane ratings . Numerous detail changes were made internally and externally to the engine to withstand increased power ratings and to incorporate advances in engineering practices. The Merlin consumed an enormous volume of air at full power (equivalent to

4141-402: The Peregrine and Vulture were both cancelled in 1943, and by mid-1943 the Merlin was supplemented in service by the larger Griffon . The Griffon incorporated several design improvements and ultimately superseded the Merlin. Initially the new engine was plagued with problems such as failure of the accessory gear trains and coolant jackets. Several different construction methods were tried before

Continental XI-1430 - Misplaced Pages Continue

4242-576: The Spitfire used a variation of this exhaust system fitted with forward-facing intake ducts to distribute hot air out to the wing-mounted guns to prevent freezing and stoppages at high altitudes, replacing an earlier system that used heated air from the engine coolant radiator. The latter system had become ineffective due to improvements to the Merlin itself which allowed higher operating altitudes where air temperatures are lower . Ejector exhausts were also fitted to other Merlin-powered aircraft. Central to

4343-444: The U.S. became available, the engine was adapted to use a conventional liquid-cooling system. The Hart was subsequently delivered to Rolls-Royce where, as a Merlin testbed , it completed over 100 hours of flying with the Merlin C and E engines. In 1935, the Air Ministry issued a specification, F10/35 , for new fighter aircraft with a minimum airspeed of 310  mph (500  km/h ). Fortunately, two designs had been developed:

4444-477: The altitude performance of the Merlin engine necessitated the employment of a two-stage supercharger. As the Merlin evolved so too did the supercharger; the latter fitting into three broad categories: The Merlin supercharger was originally designed to allow the engine to generate maximum power at an altitude of about 16,000 ft (4,900 m). In 1938 Stanley Hooker, an Oxford graduate in applied mathematics, explained "... I soon became very familiar with

4545-478: The basic design of the Merlin was set. Early production Merlins were unreliable: common problems were cylinder head cracking, coolant leaks, and excessive wear to the camshafts and crankshaft main bearings . The prototype, developmental, and early production engine types were the: The Merlin II and III series were the first main production versions of the engine. The Merlin III was the first version to incorporate

4646-405: The change to a V-layout allowed the individual cylinder heads to be cast as a single piece. Mounted at either end, a Y-shaped plate provided stiffness, while containing the camshaft drives. Continental built the first I-1430 engine in 1938 and successfully tested it in 1939. At the time it was an extremely competitive design, offering at least 1,300 hp (970 kW) from a 23-liter displacement;

4747-470: The company convention of naming its piston aero engines after birds of prey, Rolls-Royce named the engine the Merlin after a small, Northern Hemisphere falcon ( Falco columbarius ). Two more Rolls-Royce engines developed just prior to the war were added to the company's range. The 885 hp (660 kW) Rolls-Royce Peregrine was an updated, supercharged development of their V-12 Kestrel design, while

4848-469: The concept. In 2019 Dolphin N2 was purchased by FPT Industrial who claim The Recuperated Split Cycle engine has the potential to reduce fossil fuel use by up to 30% whilst simultaneously reducing air pollutants to well below any future planned legislation. In 1915 Ricardo set up a new company, "Engine Patents Ltd.", which developed the engine that would eventually be used in the first successful tank design,

4949-488: The construction of the Merlin supercharger and carburettor ... Since the supercharger was at the rear of the engine it had come in for pretty severe design treatment, and the air intake duct to the impeller looked very squashed ..." Tests conducted by Hooker showed the original intake design was inefficient, limiting the performance of the supercharger. Hooker subsequently designed a new air intake duct with improved flow characteristics, which increased maximum power at

5050-483: The contemporary Rolls-Royce Merlin offered about 1,000 hp (700 kW) from 27 L displacement, while the contemporary German competitor to the 35-litre displacement Junkers Jumo 211 engine, the Daimler-Benz DB 601 inverted V12, offered slightly more power at 1,100 hp (820 kW), but was much larger, at 33 L displacement, with some 19,000 examples produced in its various versions. While

5151-482: The crankcase, was common for liquid-cooled Central Powers World War I -era inline-6 aviation engines, as in the German Mercedes D.III of nearly two decades earlier – and had been used for the 1918-era Allied Liberty L-12 liquid-cooled aviation engine with significant success – it had fallen from use in favor of engines featuring a monobloc engine design philosophy, with a cylinder block that combined

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5252-416: The cylinders and the crankcase, leading to much stiffer engines, that were better able to handle increased power. The USAAC proposed an engine of about 1200 cubic inches (20 L), hoping the engine's smaller size would lead to reduced drag and hence improved range. By 1932, the USAAC's encouraging efforts led the Army to sign a development contract with Continental Motors Company for the continued development of

5353-467: The design of a device to manoeuvre battle tanks into position aboard railway wagons. Around 8000 engines were produced to power the tanks, making this engine the UK's first mass-produced internal combustion engine. Many more of these engines found further applications powering generators in workshops, hospitals and camps. The success of this venture yielded £30,000 in royalties and led to Ricardo being able to buy

5454-610: The design of the combustion chambers and fuel control system of Sir Frank Whittle 's jet engine. In 1974, at the age of 89, Ricardo suffered a pelvic injury in a fall. He died six weeks later, on 18 May. On 16 June 2005 a blue plaque was placed outside the house where Ricardo was born in Bedford Square , London. On 1 July 2010, the Institution of Mechanical Engineers bestowed an Engineering Heritage Award on Sir Harry Ricardo in recognition of his life and work as one of

5555-483: The design of the two-stage supercharger forged ahead, Rolls-Royce also continued to develop the single-stage supercharger, resulting in 1942 in the development of a smaller "cropped" impeller for the Merlin 45M and 55M; both of these engines developed greater power at low altitudes. In squadron service the LF.V variant of the Spitfire fitted with these engines became known as the "clipped, clapped, and cropped Spitty" to indicate

5656-538: The end of its production run in 1950, 168,176 Merlin engines had been built; over 112,000 in Britain and more than 55,000 under licence in the U.S. The existing Rolls-Royce facilities at Osmaston, Derby were not suitable for mass engine production although the floor space had been increased by some 25% between 1935 and 1939; Hives planned to build the first two or three hundred engines there until engineering teething troubles had been resolved. To fund this expansion,

5757-472: The engine before discharging the exhaust stream on the outboard side of the UPP nacelle. As a result, sound levels were reduced by between 5 and 8 decibels . The modified exhaust also conferred an increase in horsepower over the unmodified system of 38 hp (28 kW), resulting in a 5 knot improvement in true air speed. Still-air range of the aircraft was also improved by around 4 per cent. The modified engine

5858-440: The engine design. The contract limited Continental's role to construction and testing, leaving the actual engineering development to the Army. A second cylinder was added to Hyper No. 1 to make a horizontal-opposed engine for evaluation of an opposed-piston 12-cylinder engine. After running the modified engine with different combinations of cylinder bore and stroke, it was found that the high coolant temperatures required to maintain

5959-646: The engine was producing exceptional power for its displacement, the reason it was not put into production may have had to do with its weight. Both the Rolls-Royce/Packard Merlin V-1650 and the Allison V-1710 were in production, with similar power and better Power/Weight Ratios. The V-1710 was 1395 lbs, 385 pounds lighter than I-1430 with a power-to-weight ratio of 1.05. The Merlin V-1650 weighed in at 1640, 25 pounds more than

6060-538: The foremost engineers of the twentieth century. The first internal combustion engine which Harry Ricardo designed and built as a schoolboy currently displays this Engineering Heritage plaque in the Ricardo plc company exhibition area. In 1915, Ricardo formed Engine Patents Ltd, the company which is today known as Ricardo PLC . In this year he was contacted by the Royal Naval Air Service to help with

6161-428: The fuel supply line together with a diaphragm fitted in the float chamber, jocularly nicknamed " Miss Shilling's orifice ", after its inventor, went some way towards curing fuel starvation in a dive by containing fuel under negative G; however, at less than maximum power a fuel-rich mixture still resulted. Another improvement was made by moving the fuel outlet from the bottom of the S.U. carburettor to exactly halfway up

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6262-537: The great Ford factory at Manchester started production, Merlins came out like shelling peas ...". Some 17,316 people worked at the Trafford Park plant, including 7,260 women and two resident doctors and nurses. Merlin production started to run down in August 1945, and finally ceased on 23 March 1946. Total Merlin production at Trafford Park was 30,428. As the Merlin was considered to be so important to

6363-426: The induction swirl chamber, which was an attempt to achieve orderly air motion in a diesel engine, the swirl being initiated by inclined ports and accentuated by forcing the air into a small cylindrical volume. Finally he developed the compression swirl chamber for diesel engines. This design embodied intense swirl with a reasonable rate of pressure rise and good fuel consumption. The compression swirl chamber design

6464-616: The land and set up the company on its present site in 1919. Rolls-Royce Merlin The Rolls-Royce Merlin is a British liquid-cooled V-12 piston aero engine of 27-litre (1,650 cu in) capacity . Rolls-Royce designed the engine and first ran it in 1933 as a private venture. Initially known as the PV-12 , it was later called Merlin following the company convention of naming its four-stroke piston aero engines after birds of prey . The engine benefitted from

6565-428: The level maximum speed of the Spitfire by 10 mph (16 km/h) to 360 mph (580 km/h). The first versions of the ejector exhausts featured round outlets, while subsequent versions of the system used "fishtail" style outlets, which marginally increased thrust and reduced exhaust glare for night flying. In September 1937 the Spitfire prototype, K5054 , was fitted with ejector type exhausts. Later marks of

6666-481: The maximum boost pressure at which the engine could be run using 87-octane fuel was +6 pounds per square inch (141 kPa; 1.44  atm ). However, as early as 1938, at the 16th Paris Air Show , Rolls-Royce displayed two versions of the Merlin rated to use 100-octane fuel. The Merlin R.M.2M was capable of 1,265 hp (943 kW) at 7,870 feet (2,400 m), 1,285 hp (958 kW) at 9,180 feet (2,800 m) and 1,320 hp (980 kW) on take-off; while

6767-424: The number of required sub-contracted parts such as crankshafts, camshafts and cylinder liners eventually fell short and the factory was expanded to manufacture these parts "in house". Initially the local authority promised to build 1,000 new houses to accommodate the workforce by the end of 1938, but by February 1939 it had only awarded a contract for 100. Hives was incensed by this complacency and threatened to move

6868-476: The oil leaks that had been a problem with the early Merlin I, II and III series. The process of improvement continued, with later versions running on higher octane ratings, delivering more power. Fundamental design changes were also made to all key components, again increasing the engine's life and reliability. By the end of the war the "little" engine was delivering over 1,600 hp (1,200 kW) in common versions, and as much as 2,030 hp (1,510 kW) in

6969-653: The premises in October, one month after the outbreak of war. The factory was fully occupied by September 1940. A housing crisis also occurred at Glasgow, where Hives again asked the Air Ministry to step in. With 16,000 employees, the Glasgow factory was one of the largest industrial operations in Scotland. Unlike the Derby and Crewe plants, which relied significantly on external subcontractors , it produced almost all

7070-500: The problem he built a unique variable-compression test engine. This led to the development of an octane rating system for fuels, and considerable investment into octane improving additives and refining systems. The dramatic reduction in fuel use as a result of higher-octane fuel was directly responsible for allowing Alcock and Brown to fly the Atlantic in their Vickers Vimy bombers adapted with his modifications. In 1919 Ricardo

7171-522: The production of the Rolls-Royce Avon turbojet and others, the factory was closed in 2005. The Ford Motor Company was asked to produce Merlins at Trafford Park , Stretford , near Manchester , and building work on a new factory was started in May 1940 on a 118-acre (48 ha) site. Built with two distinct sections to minimise potential bomb damage, it was completed in May 1941 and bombed in

7272-454: The prototype high-altitude Vickers Wellington V bomber, Rolls-Royce started experiments on the design of a two-stage supercharger and an engine fitted with this was bench-tested in April 1941, eventually becoming the Merlin 60. The basic design used a modified Vulture supercharger for the first stage while a Merlin 46 supercharger was used for the second. A liquid-cooled intercooler on top of

7373-475: The racing experiences of precursor engines in the 1930s. After several modifications, the first production variants of the PV-12 were completed in 1936. The first operational aircraft to enter service using the Merlin were the Fairey Battle , Hawker Hurricane and Supermarine Spitfire . The Merlin remains most closely associated with the Spitfire and Hurricane, although the majority of the production run

7474-592: The required output were impractical. A third high-performance single-cylinder engine was then constructed with lower operating parameters. This one-cylinder engine was designated "Hyper No. 2", and became the test bed for developing the cylinders that would become the Continental O-1430 ("O" for "opposed") engine. It would require a ten-year development period which changed the layout to first an upright V-12 engine and later, an inverted V-12 engine, before becoming reliable enough to consider for full production as

7575-473: The same month. At first, the factory had difficulty in attracting suitable labour, and large numbers of women, youths and untrained men had to be taken on. Despite this, the first Merlin engine came off the production line one month later and it was building the engine at a rate of 200 per week by 1943, at which point the joint factories were producing 18,000 Merlins per year. In his autobiography Not much of an Engineer , Sir Stanley Hooker states: "... once

7676-429: The selling price. The company fared better making two-stroke engines for fishing boats. In 1911 the firm collapsed and Ralph departed for India . Ricardo continued to design engines for small electric lighting sets; these were produced by two companies until 1914. Interest in the 1909 Ricardo designed split cycle Dolphin engine continues and in 2017 Ricardo PLC formed a new consortium called Dolphin-N2 to further develop

7777-475: The shortened wingspan , the less-than-perfect condition of the used airframes , and the cropped supercharger impeller. The use of carburettors was calculated to give a higher specific power output, due to the lower temperature, hence greater density, of the fuel/air mixture compared to injected systems. Initially Merlins were fitted with float controlled carburettors. However, during the Battle of Britain it

7878-437: The side, which allowed the fuel to flow equally well under negative or positive g. Further improvements were introduced throughout the Merlin range: 1943 saw the introduction of a Bendix-Stromberg pressure carburettor that injected fuel at 5 pounds per square inch (34  kPa ; 0.34 bar ) through a nozzle directly into the supercharger, and was fitted to Merlin 66, 70, 76, 77 and 85 variants. The final development, which

7979-587: The smaller and unproven Continental with about the same power/weight ratio of about 1.00. It did not seem the XI-1430 would be the solution to any important problem. It was not until 1943 that the 1,600 hp (1,190 kW) IV-1430 was tested extensively in the Lockheed XP-49 , a modified version of the P-38 Lightning . It was also to be used in the production version of the Bell XP-76 , which

8080-516: The smaller one sold about 50 engines until 1914, when the war halted production. In 1909 Ricardo designed a novel two-stroke split cycle 3.3-litre engine for his cousin Ralph Ricardo, who had established a small car manufacturing company, "Two Stroke Engine Company", at Shoreham-by-Sea . The engine was to be used in the Dolphin car. The cars were well made, but they cost more to make than

8181-431: The success of the Merlin was the supercharger. A.C. Lovesey , an engineer who was a key figure in the design of the Merlin, delivered a lecture on the development of the Merlin in 1946; in this extract he explained the importance of the supercharger: 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

8282-425: The supercharger casing was used to prevent the compressed air/fuel mixture from becoming too hot. Also considered was an exhaust-driven turbocharger , but although a lower fuel consumption was an advantage, the added weight and the need to add extra ducting for the exhaust flow and waste-gates meant that this option was rejected in favour of the two-stage supercharger. Fitted with the two-stage two-speed supercharger,

8383-408: The two-speed superchargers designed by Rolls-Royce, resulting in increased power at higher altitudes than previous versions. Another improvement, introduced with the Merlin X, was the use of a 70%–30% water-glycol coolant mix rather than the 100% glycol of the earlier versions. This substantially improved engine life and reliability, removed the fire hazard of the flammable ethylene glycol , and reduced

8484-630: The very latest version as used in the de Havilland Hornet over 2,000 horsepower (1,500 kW). One of the most successful aircraft engines of the World War II era, some 50 versions of the Merlin were built by Rolls-Royce in Derby , Crewe and Glasgow , as well as by Ford of Britain at their Trafford Park factory , near Manchester . A de-rated version was also the basis of the Rolls-Royce/Rover Meteor tank engine. Post-war,

8585-403: The volume of a single-decker bus per minute), and with the exhaust gases exiting at 1,300 mph (2,100 km/h) it was realised that useful thrust could be gained simply by angling the gases backwards instead of venting sideways. During tests, 70 pounds-force (310 N ; 32  kgf ) thrust at 300 mph (480 km/h), or roughly 70 hp (52 kW) was obtained, which increased

8686-595: The war effort, negotiations were started to establish an alternative production line outside the UK. Rolls-Royce staff visited North American automobile manufacturers to select one to build the Merlin in the U.S. or Canada. Henry Ford rescinded an initial offer to build the engine in the U.S. in July 1940, and the Packard Motor Car Company was selected to take on the $ 130,000,000 Merlin order (equivalent to $ 2.83 billion in 2023 dollars ). Agreement

8787-488: The whole operation, but timely intervention by the Air Ministry improved the situation. In 1940 a strike took place when women replaced men on capstan lathes , the workers' union insisting this was a skilled labour job; however, the men returned to work after 10 days. Total Merlin production at Crewe was 26,065. The factory was used postwar for the production of Rolls-Royce and Bentley motor cars and military fighting vehicle power plants. In 1998 Volkswagen AG bought

8888-542: The world's first volume production diesel passenger car, the 1934 Citroën Rosalie . This meant that Britain led the world in the field of high-speed diesels for road transport at that time. This advantage was lost to the United Kingdom as a result of the heavy tax imposed on diesel fuel in the budget of 1938. Ricardo designed the 1921 T.T. Vauxhall engine which was described by Cecil Clutton in Motor Sport as

8989-426: Was 1,175 hp (876 kW) at 18,000 ft (5,500 m). These figures were achieved at 2,850 rpm engine speed using +9 pounds per square inch (1.66  atm ) (48") boost. In 1940, after receiving a request in March of that year from the Ministry of Aircraft Production for a high-rated (40,000 ft (12,000 m)) Merlin for use as an alternative engine to the turbocharged Hercules VIII used in

9090-522: Was 32,377. The original factory closed in March 2008, but the company maintains a presence in Derby. To meet the increasing demand for Merlin engines, Rolls-Royce started building work on a new factory at Crewe in May 1938, with engines leaving the factory in 1939. The Crewe factory had convenient road and rail links to their existing facilities at Derby. Production at Crewe was originally planned to use unskilled labour and sub-contractors with which Hives felt there would be no particular difficulty, but

9191-438: Was an English engineer who was one of the foremost engine designers and researchers in the early years of the development of the internal combustion engine . Among his many other works, he improved the engines that were used in the first tanks , oversaw the research into the physics of internal combustion that led to the use of octane ratings , was instrumental in development of the sleeve valve engine design, and invented

9292-535: Was called a "Comet" design (patented in 1931) and was subsequently licensed to a large number of companies for use in trucks, buses, tractors and cranes, as well as private cars and taxis. A Comet combustion chamber was used in the first Associated Equipment Company (AEC) diesel buses operated in 1931 by London General Omnibus Co , later part of the London Passenger Transport Board / London Transport . A later development of it featured in

9393-561: Was canceled before production began. In 1944 it was also tested in the McDonnell XP-67 . Interest in the design had largely disappeared by then; piston engines with the same power or greater ratings were widely available, the Merlin for example had improved tremendously and was offering at least 1,500 hp (1,120 kW), and the military and aircraft builders were already starting to focus on jet engines . Only twenty-three I-1430 series engines were delivered, later redesignated

9494-625: Was concentrated on civil derivatives of the Merlin. Development of what became the "Transport Merlin" (TML) commenced with the Merlin 102 (the first Merlin to complete the new civil type-test requirements) and was aimed at improving reliability and service overhaul periods for airline operators using airliner and transport aircraft such as the Avro Lancastrian , Avro York (Merlin 500-series), Avro Tudor II and IV (Merlin 621), Tudor IVB and V (Merlin 623), TCA Canadair North Star (Merlin 724) and BOAC Argonaut (Merlin 724-IC). By 1951

9595-988: Was designated the "TMO" and the modified exhaust system was supplied as kit that could be installed on existing engines either by the operator or by Rolls-Royce. Power ratings for the civil Merlin 600, 620, and 621-series was 1,160 hp (870 kW) continuous cruising at 23,500 feet (7,200 m), and 1,725 hp (1,286 kW) for take-off. Merlins 622–626 were rated at 1,420 hp (1,060 kW) continuous cruising at 18,700 feet (5,700 m), and 1,760 hp (1,310 kW) for take-off. Engines were available with single-stage, two-speed supercharging (500-series), two-stage, two-speed supercharging (600-series), and with full intercooling, or with half intercooling/charge heating, charge heating being employed for cold area use such as in Canada. Civil Merlin engines in airline service flew 7,818,000 air miles in 1946, 17,455,000 in 1947, and 24,850,000 miles in 1948. From Jane's : Most of

9696-409: Was fitted to the 100-series Merlins, was an S.U. injection carburettor that injected fuel into the supercharger using a fuel pump driven as a function of crankshaft speed and engine pressures. At the start of the war, the Merlin I, II and III ran on the then standard 87-octane aviation spirit and could generate just over 1,000 hp (750 kW) from its 27-litre (1,650-cu in) displacement:

9797-402: Was for the four-engined Avro Lancaster heavy bomber. The Merlin continued to benefit from a series of rapidly-applied developments, derived from experiences in use since 1936. These markedly improved the engine's performance and durability. Starting at 1,000 horsepower (750 kW) for the first production models, most late war versions produced just under 1,800 horsepower (1,300 kW), and

9898-462: Was found that if Spitfires or Hurricanes were to pitch nose down into a steep dive, negative g -force ( g ) produced temporary fuel starvation causing the engine to cut-out momentarily. By comparison, the contemporary Bf 109E , which had direct fuel injection , could "bunt" straight into a high-power dive to escape attack. RAF fighter pilots soon learned to avoid this with a "half-roll" of their aircraft before diving in pursuit. A restrictor in

9999-430: Was no mechanical time limit mechanism, but pilots were advised not to use increased boost for more than a maximum of five minutes, and it was considered a "definite overload condition on the engine"; if the pilot resorted to emergency boost he had to report this on landing, when it was noted in the engine log book, while the engineering officer was required to examine the engine and reset the throttle gate. Later versions of

10100-600: Was refining the Merlin. As a result, the Peregrine saw use in only two aircraft: the Westland Whirlwind fighter and one of the Gloster F.9/37 prototypes. The Vulture was fitted to the Avro Manchester bomber, but proved unreliable in service and the planned fighter using it – the Hawker Tornado – was cancelled as a result. With the Merlin itself soon pushing into the 1,500 hp (1,100 kW) range,

10201-439: Was studying the phenomena affecting the combustion within the petrol engine and the diesel engine . He realised that turbulence within the combustion chamber increased flame speed, and that he could achieve this by offsetting the cylinder head . He also realised that making the chamber as compact as possible would reduce the distance that the flame had to travel and would reduce the likelihood of detonation. He later developed

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