The Sunbeam Arab was a British First World War-era

aero engine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Aircraft using power components are referred to as powered flight. Most aircraft engines are either piston engines or gas turbin ...

Design and development

By 1916 the demand for aero-engines was placing huge demands on manufacturing. To help ease the pressure, the

War Office The War Office has referred to several British government organisations throughout history, all relating to the army. It was a department of the British Government responsible for the administration of the British Army between 1857 and 1964, at ...

standardised on engines of about ; one of these was a V-8

water-cooled Cooling tower and water discharge of a nuclear power plant Water cooling is a method of heat removal from components and industrial equipment. Evaporative cooling using water is often more efficient than air cooling. Water is inexpensive and no ...

engine from Sunbeam known as the Arab. Using cast aluminium alloy cylinder blocks and heads with die-cast aluminium alloy pistons, the Arab had a bore of and stroke of for a capacity of , developing at 2,000 rpm. First bench-run in 1916, the Arab was obviously inspired by the Hispano-Suiza V-8 engines but with very little in common when examined in detail. After submission to the Internal Combustion Engine Committee of the Advisory Committee on Aeronautics Sunbeam received an order for 1,000 in March 1917. The order formed part of the strategy of Sir William Weir to bypass the skilled engineering workforce needed to build

Rolls-Royce Eagle The Rolls-Royce Eagle was the first aircraft engine to be developed by Rolls-Royce Limited. Introduced in 1915 to meet British military requirements during World War I, it was used to power the Handley Page Type O bombers and a number of oth ...

and

Falcon Falcons () are birds of prey in the genus ''Falco'', which includes about 40 species. Some small species of falcons with long, narrow wings are called hobbies, and some that hover while hunting are called kestrels. Falcons are widely distrib ...

engines, through the use of cast aluminium cylinder blocks that minimised the need for machining. However, the Arab was ordered before flight testing, and when the engine went into the air, chronic vibration problems emerged which were never cured. The initial order was increased to 2,000 in June 1917 as well as another 2,160 to be built by

Austin Motors The Austin Motor Company Limited was a British manufacturer of motor vehicles, founded in 1905 by Herbert Austin in Longbridge. In 1952 it was merged with Morris Motors Limited in the new holding company British Motor Corporation (BMC) Lim ...

(1,000),

Lanchester Motor Company The Lanchester Motor Company Limited is a marque & former British car manufacturer in active trade between 1899 and 1955. Though the Lanchester Motor Company Limited is still registered as an active company and accounts are filed each year, th ...

(300),

Napier & Son D. Napier & Son Limited was a British engineering company best known for its luxury motor cars in the Edwardian era and for its aero engines throughout the early to mid-20th century. Napier was founded as a precision engineering company in 1 ...

(300), and

Willys Overland Willys (pronounced , "Willis") was a brand name used by Willys–Overland Motors, an American automobile company, founded by John North Willys. It was best known for its design and production of World War II–era military jeeps (MBs), Willys ...

(560) in the

United States of America The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguo ...

. Despite this massive manufacturing effort, the Arab proved largely useless, and nearly half of the production run of the Bristol Fighter, Britain’s best two-seat fighter of the First World War, went into storage because plans to power the aircraft with the Arab were abandoned due to the engine’s failings. Service use of the Arab was limited because of poor reliability and persistent vibration problems, causing some 2,350 orders to be cancelled and remaining orders 'settled', compensating manufacturers for costs incurred. Developed from the Arab were the inverted V-8 Sunbeam Bedouin, straight-six Sunbeam Dyak, W-12 Sunbeam Kaffir, and 20-cylinder radial Sunbeam Malay.

Variants

;Arab :The production engine loosely based on the

Hispano-Suiza 8 The Hispano-Suiza 8 is a Internal combustion engine cooling, water-cooled V8 engine, V8 SOHC aero engine introduced by Hispano-Suiza in 1914 that went on to become the most commonly used liquid-cooled engine in the aircraft of the Entente Powers ...

V-8 engines. ;Bedouin :In common with many other contemporary engine manufacturers, the Arab was redesigned to run inverted and given the name Sunbeam Bedouin. Intended to provide better forward visibility for single-engined aircraft, there is no evidence that the Bedouoin was fitted to an aircraft or flew. ;Kaffir :A W-12 broad-arrow engine using blocks, heads and valve-gear from the Arab, giving . Bore remained the same at , but with a stroke of . ; Dyak :A straight-six extrapolation of the Arab retaining the stroke and bore of the Arab, but with only two valves per cylinder as opposed to the three valves on the Arab. ;

Pathan Pashtuns (, , ; ;), also known as Pakhtuns, or Pathans, are an Iranic ethnic group primarily residing in southern and eastern Afghanistan and northwestern Pakistan. They were historically also referred to as Afghans until 1964 after the ...

:Coatalen expressed his interest in diesel engines by designing a diesel derivative of the Dyak with the same attributes, developing at 1,500 rpm. Only prototypes of the Pathan were built. ;Malay :The ''Sunbeam Malay'' was a 20-cylinder radial aircraft engine of capacity manufactured by

Sunbeam A sunbeam, in meteorological optics, is a lightbeam, beam of sunlight that appears to radiate from the position of the Sun. Shining through openings in clouds or between other objects such as mountains and buildings, these beams of light scatter ...

using five four-cylinder blocks from the Arab arranged around a central crankshaft. The Malay retained the × bore and stroke of the Arab, as well as the three valves per cylinder and overhead camshafts. Nominally rated at , the Malay was not put into production.Brew 1998

Applications

''Data from Brew''. * Armstrong-Whitworth F.K.10 *

Avro 530 The Avro 530 was a British two-seat fighter biplane designed in 1916 to compete with the Bristol F.2A. The plane was first flown in July 1917. It was of fabric-covered wooden construction, powered by a 200 hp (150 kW) Hispano-Suiza e ...

* Bristol F.2b Fighter *

Bristol Scout F The Bristol Scout E and F were a British single-seat biplane fighters built in 1916 to use newer and more powerful engines. It was initially powered by the Sunbeam Arab, but the third prototype was used as a testbed for the Cosmos Mercury, mark ...

* Fairey F.2a *

Fairey N.2a The Fairey Aviation Company Fairey III was a family of British reconnaissance biplanes that enjoyed a very long production and service history in both landplane and seaplane variants. First flying on 14 September 1917, examples were still in u ...

Grain Griffin The Grain Griffin was a British carrier-based reconnaissance aircraft developed and built by the RNAS Marine Experimental Depot, Port Victoria, during the First World War. A development of the unsuccessful Sopwith B.1 bomber, the Grain Griff ...

* Martinsyde F.2 * Norman Thompson N.2c * Norman Thompson NT.2b * Royal Aircraft Factory AE.3 Ram * Royal Aircraft Factory SE.5a * Sage 4B Seaplane Trainer *

Short Improved Navyplane The Short S.27 and its derivative, the Short Improved S.27 (sometimes called the Short-Sommer biplane), were a series of early British aircraft built by Short Brothers. They were used by the Admiralty and Naval Wing of the Royal Flying Corps fo ...

Sopwith Cuckoo The Sopwith T.1 Cuckoo was a British biplane torpedo bomber used by the Royal Naval Air Service (RNAS), and its successor organization, the Royal Air Force (RAF). The T.1 was the first landplane specifically designed for carrier operations, but ...

* Sunbeam 1917 Bomber * Supermarine Baby

Specifications (Arab I)

References

Bibliography

* Brew, Alec. ''Sunbeam Aero-Engines''. Shrewsbury: Airlife Publishing 1998 * Ewer, Peter. 'William Weir: architect of air power? The First World War chapter', ''The International Journal for the History of Engineering & Technology'', 2023 pp.1-19. . *Lumsden, Alec. ''British Piston Engines and their Aircraft''. Marlborough, Wiltshire: Airlife Publishing, 2003. .

External links

* * {{Sunbeam aeroengines

Arab Arabs (, , ; , , ) are an ethnic group mainly inhabiting the Arab world in West Asia and North Africa. A significant Arab diaspora is present in various parts of the world. Arabs have been in the Fertile Crescent for thousands of years ...

1910s aircraft piston engines