The Sunbeam Afridi was an aero-engine produced by
Sunbeam
A sunbeam, in meteorological optics, is a 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 particle-scattered sunl ...
during the
First World War
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
.
Design and development
Conceived to replace the
Crusader/Zulu on the production lines, Louis Coatalen designed a companion engine for the V-12
Cossack
The Cossacks , es, cosaco , et, Kasakad, cazacii , fi, Kasakat, cazacii , french: cosaques , hu, kozákok, cazacii , it, cosacchi , orv, коза́ки, pl, Kozacy , pt, cossacos , ro, cazaci , russian: казаки́ or ...
, giving it the name Afridi. The Afridi was a much smaller engine than the Cossack and also spawned a whole family of derivative engines.
The major attributes of the Afridi were a bore of and stroke of displacing for a power output of at 2,000rpm. The twin overhead camshafts were driven by gears, directly operating two inlet and two exhaust valves per cylinder. Two Claudel-Hobson carburettors on the outsides of the blocks fed mixture to the cylinders, where it was ignited by the dual ignition system energised by four 6-cyl magnetos.
Three hundred Afridis were ordered, of which 299 were delivered and 100 converted to Sunbeam Maoris. Service use was mainly in
Curtiss R.2 tractor biplanes and various Short seaplanes.
Maori
A direct development of the Afridi, the Sunbeam Maori was far more successful. In similar fashion to Coatalen′s development of Sunbeam's side-valve engines he increased the bore to retaining the stroke of , displacing for a power output of at 2,000rpm driving a geared propeller.
Production of the Maori began in April 1917, including 100 Afridis which were converted to Maoris on the production line as the Maori Mk.I, with new-build Maoris designated as Maori Mk.II. Converted Afridis, (Maori Mk.I), were rated at at 2,000rpm, whilst new-build Maori Mk.IIs were rated at at 2,000rpm.
Maoris found favour with Short and Fairey seaplanes as well as
Handley Page O/400
The Handley Page Type O was a biplane bomber used by Britain during the First World War. When built, the Type O was the largest aircraft that had been built in the UK and one of the largest in the world. There were two main variants, the Handl ...
bombers, with development continuing to give the Maori Mk.III and Maori Mk.IV. The Maori Mk.III introduced cylinder banks with exhaust ports on the outside rather than the inside of the Vee and the carburettors on the inside. The Mk.III was rated at .
The final Maori version was designed specifically for use in airships as the Maori Mk.IV, with controls mounted directly on the rear of the engine, flywheel, enlarged cooling system and water-cooled exhaust pipes. Fitted to
R33 and
R34 R34 may refer to:
* R34 (New York City Subway car)
* R34 (South Africa)
* HM Airship ''R.34'', a rigid airship of the Royal Air Force
* , a destroyer of the Royal Navy
* Nissan Skyline (R34), a mid-size car
* Nissan Skyline GT-R (R34), a sports ca ...
, five Maori Mk.IVs were fitted to each airship in gondolas, allowing the engines to be tended by on-board mechanics.
Manitou
The Sunbeam Manitou was a further development of the V-12 Maori Mk.III; work on it began by
Louis Coatalen
Louis Hervé Coatalen (11 September 1879 – 23 May 1962) was an automobile engineer and racing driver born in Brittany who spent much of his adult life in Britain and took British nationality. He was a pioneer of the design and development of inte ...
in 1917, using aluminium alloy rather than cast iron blocks, cast in blocks of three cylinders, a typical Sunbeam feature. Bore was increased to , but stroke remained at . The cylinder bank were at a 60° vee, with twin overhead camshafts on each bank operating four valves per cylinder. Two
Claudel-Hobson
Claudel-Hobson was a series of British carburettors manufactured by H. M. Hobson Ltd.
Introduced in 1908, they were widely used on British car and aircraft engines in the early 20th century. Applications included Sunbeam automobiles as well as ...
carburettors and two
BTH BTH may refer to:
* Bachelor of Theology (B.Th.)
* Bacterial two-hybrid system, a genetic technique to detect interactions among proteins
* Benzothiadiazole (disambiguation)
* Blekinge Institute of Technology (''Blekinge Tekniska Högskola''), Swe ...
magnetos delivered mixture to the cylinders and ignited it. Fitted with a reduction gear for aircraft the engine developed at 2,000rpm., later increased to .
Unsuccessful as an
aero-engine
An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years many ...
, it is best known for having powered the
Sunbeam 350HP
The Sunbeam 350HP is an aero-engined car built by the Sunbeam company in 1920, the first of several land speed record-breaking cars with aircraft engines.
Design
The car was fitted with a purpose built 18.3-litre V12 engine based on a hybrid ...
racing car.
Despite large orders for 840 Manitous, only 13 were built before production stopped. Those that were built found favour as motor-boat power-plants and only one flew trials in a
Short 184
The Short Admiralty Type 184, often called the Short 225 after the power rating of the engine first fitted, was a British two-seat reconnaissance, bombing and torpedo carrying folding-wing seaplane designed by Horace Short of Short Brothers. It ...
seaplane. Four were fitted to the '' '
Maple Leaf V' '' and a specially built Manitou was fitted to the
350hp Sunbeam racing car.
350hp Sunbeam
The Manitou was noteworthy for being fitted to the ''
350hp Sunbeam'' racing car in 1920, which was later bought by
Malcolm Campbell
Major Sir Malcolm Campbell (11 March 1885 – 31 December 1948) was a British racing motorist and motoring journalist. He gained the world speed record on land and on water at various times, using vehicles called ''Blue Bird'', including a 1 ...
to set land speed records and became one of
Campbell's Blue Birds.
Coatalen redesigned the engine substantially for use in the 350 hp Sunbeam car. The twin-cam four-valve head was replaced by a single-cam three-valve head, possibly from the
Arab
The Arabs (singular: Arab; singular ar, عَرَبِيٌّ, DIN 31635: , , plural ar, عَرَب, DIN 31635: , Arabic pronunciation: ), also known as the Arab people, are an ethnic group mainly inhabiting the Arab world in Western Asia, ...
, the increase in bore to 120 mm allowing space for three valves.
To ensure adequate bearing surface at the big ends Coatalen retained the articulated connecting rods, where one rod runs on the crankshaft journal, but the other acts indirectly, through a journal on the other rod. The difficulty is that this gives a slightly different piston stroke and journal rotation centres for each bank, which can lead to unbalance and possible vibration problems. Stroke was thus 135 mm on one bank and 142 mm on the other.
After initial use by Coatalen, the car was sold to
Sir Malcolm Campbell
Major Sir Malcolm Campbell (11 March 1885 – 31 December 1948) was a British racing motorist and motoring journalist. He gained the world speed record on land and on water at various times, using vehicles called ''Blue Bird'', including a 1 ...
for an attempt at the world land speed record.
Tartar
The Sunbeam Tartar was an obscure experimental engine intended for use on airships. The V-12 Tartar was of radically different construction in that individual cylinders formed each bank as opposed to groups of three in integral blocks. Built in prototype form only, the Tartar retained the bore, stroke, and dual ignition system of the Manitou; but introduced a single overhead camshaft operating the four valves in each cylinder via rockers. From its displacement the Tartar developed but failed to gain any orders; however it may have provided inspiration for the large
Sunbeam Sikh airship engine which also had individual cylinders.
Applications
*''Data from:''
*
Armstrong-Whitworth FK.10 (Afridi)
*
Avro 519
The Avro 519 was a British bomber aircraft of the First World War, a development of the Avro 510 seaplane. They were two-bay biplanes of conventional configuration with greatly uneven span. Two single-seat examples, powered by a single 150 ...
(Afridi)
*
Avro 529 Silver King (Maori)
*
Curtiss H.12 (Maori)
*
Curtiss R.2 (Afridi)
*
Fairey F.2a Patrol (Maori)
*
Fairey F.22 Campania (Maori)
*
Fairey III
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 us ...
(Maori)
*
Grahame-White E.IV Ganymede (Maori)
*
Handley Page O/100
The Handley Page Type O was a biplane bomber used by Britain during the First World War. When built, the Type O was the largest aircraft that had been built in the UK and one of the largest in the world. There were two main variants, the Handle ...
(Maori)
*
Handley Page O/400
The Handley Page Type O was a biplane bomber used by Britain during the First World War. When built, the Type O was the largest aircraft that had been built in the UK and one of the largest in the world. There were two main variants, the Handl ...
(Maori)
*
HM Airship R.33 (Maori)
*
HM Airship R.34 (Maori)
*
Parnall Zeppelin-Strafer (Maori)
*
Royal Aircraft Factory CE.1 (Maori)
*
Royal Aircraft Factory RE.9
The Royal Aircraft Factory R.E.8 was a British two-seat biplane reconnaissance and bomber aircraft of the First World War designed and produced at the Royal Aircraft Factory. It was also built under contract by Austin Motors, Daimler, Standard ...
(Maori)
*
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 ...
(Afridi)
*
Short N.2A Scout (Afridi)
*
Short N.2B
The Short N.2B was a prototype British patrol seaplane of the First World War, designed and built by Short Brothers. A single-engined biplane intended to replace Short's successful Type 184, only two were built, the Fairey III being preferred ...
(Maori)
*
Short Type 184
The Short Admiralty Type 184, often called the Short 225 after the power rating of the engine first fitted, was a British two-seat reconnaissance, bombing and torpedo carrying folding-wing seaplane designed by Horace Short of Short Brothers. It ...
(Maori) (Manitou)
*
Vickers FB.27 Vimy (Maori)
*
Wight Tractor seaplane (Maori)
Specifications (Maori II)
See also
References
External links
*
{{Sunbeam aeroengines
Afridi
The Afrīdī ( ps, اپريدی ''Aprīdai'', plur. ''Aprīdī''; ur, آفریدی) are a Pashtun tribe present in Pakistan, with substantial numbers in Afghanistan. The Afridis are most dominant in Pakistan's Federally Administered Tribal ...
1910s aircraft piston engines