Sunbeam Afridi
Encyclopedia
The Sunbeam Afridi was an aero-engine produced by Sunbeam during the First World War.
Design and Development
Conceived to replace the Crusader/ZuluSunbeam Crusader
|-Specifications :-See also:-Bibliography:* Brew, Alec. Sunbeam Aero-Engines. Airlife Publishing. Shrewsbury. ISBN 1 84037 023 8-External links:* *...
on the production lines, Louis Coatalen designed a companion engine for the V-12 Cossack
Sunbeam Cossack
The Sunbeam Cossack was a British 12-cylinder aero engine that was first run in 1916. The Cossack spawned a family of engines from Sunbeam.-Design and development :...
, 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 92 mm (3.62 in) and stroke of 135 mm (5.31 in) displacing 11.476 l (699.8 cu in) for a power output of 200 hpat 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 Coatalens development of Suneams side-valve engines he increased the bore to 100 mm (3.94 in) retaining the stroke of 135 mm (5.31 in), displacing 12.27 l (748.2 cu in) for a power output of 260 hpat 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 250 hpat 2,000rpm, whilst new-build Maori Mk.IIs were rated at 260 hpat 2,000rpm.
Maoris found favour with Short and Fairey seaplanes as well as Handley Page O/400 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 275 hp.
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, 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 CoatalenLouis Coatalen
Louis Hervé Coatalen was a Breton automobile engineer.Coatalen was born in the Breton fishing town of Concarneau and went on to study engineering at the Ecole des Arts et Métiers at Cluny ....
in 1917. It used aluminium blocks rather than cast iron, cast in blocks of three cylinders, a typical Sunbeam feature. Bore was increased to 110 mm (4.33 in), but stroke remained at 135 mm (5.31 in). 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
Claudel-Hobson was a series of British carburettors manufactured by the H. M. Hobson Components Ltd..First introduced in 1908, they were widely used in British car and aircraft engines in the early 20th Century...
carburettors and two BTH magnetos delivered mixture to the cylinders and ignited it. Fitted with a reduction gear for aircraft the engine developed 300 hpat 2,000rpm., later increased to 325 hp.
Unsuccessful as an aero-engine, it is best known for having powered the Sunbeam 350HP 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 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's was noteworthy for being fitted to the 350hp Sunbeam racing car in 1920. This car was later bought by Malcolm CampbellMalcolm Campbell
Sir Malcolm Campbell was an English racing motorist and motoring journalist. He gained the world speed record on land and on water at various times during the 1920s and 1930s using vehicles called Blue Bird...
to set land speed records and became one of Campbell's Blue Birds.
Coatalen redesigned the engine substantially for use in the 350hp Sunbeam car. The twin-cam four-valve head was replaced by the single-cam three-valve head, possibly from the Arab
Sunbeam Arab
|-See also:-Bibliography:* Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.* Brew, Alec. Sunbeam Aero-Engines. Airlife Publishing. Shrewsbury. ISBN 1 84037 023 8...
, 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 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 110 mm (4.33 in) bore, 135 mm (5.31 in) stroke and dual ignition system of the Manitou, but introducing a single overhead camshaft operating the four valves in each cylinder via rockers. From the 15.4 l (939 cu in) displacement the Tartar developed 300 hp but failed to gain any orders, but may have provided inspiration for the large Sunbeam SikhSunbeam Sikh
-Bibliography:* Brew, Alec. Sunbeam Aero-Engines. Airlife Publishing. Shrewsbury. ISBN 1 84037 023 8-External links:*...
airship engine which also had individual cylinders.
Applications
Data from:- Armstrong-Whitworth FK.10 (Afridi)
- Avro 519Avro 519-External links:*...
(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 IIIFairey IIIThe 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...
(Maori) - Grahame-White E.IV Ganymede (Maori)
- Handley Page O/100 (Maori)
- Handley Page O/400 (Maori)
- HM Airship R.33 (Maori)
- HM Airship R.34 (Maori)
- Parnall Zepppelin-Strafer (Maori)
- Royal Aircraft Factory CE.1 (Maori)
- Royal Aircraft Factory RE.9 (Maori)
- Short Improved Navyplane (Afridi)
- Short N.2A Scout (Afridi)
- Short N.2BShort N.2B-References:*Barnes, C.H. Shorts Aircraft since 1900. London:Putnam, 1967.*Bruce, J.M. British Aeroplanes 1914-18. London:Putnam, 1957.*Mason, Francis K. The British Bomber since 1914. London:Putnam, 1994. ISBN 0-85177-861-5....
(Maori) - Short Type 184Short Type 184|-Manufacturers:Source: Barnes and James#Brush Electrical Engineering Co. Ltd. #Frederick Sage & Co. Ltd. #J. Samuel White #Mann, Egerton & Co. Ltd. #Phoenix Dynamo Manufacturing Company #Robey & Co. Ltd. #S E Saunders Limited...
(Maori) (Manitou) - Vickers FB.27 Vimy (Maori)
- Wight Tractor seaplane (Maori)