Sunbeam Arab


The Sunbeam Arab was a British First World War era aero engine.

Design and development

By 1916 the demand for aero-engines was placing huge demands on manufacturing. To help ease the pressure the War Office standardised on engines of about ; one of these was a V-8 water-cooled 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 National Advisory Committee Sunbeam received an order for 1,000 in March 1917, increased to 2,000 in June 1917 as well as another 2,160 to be built by Austin Motors, Lanchester Motor Company, Napier & Son, and Willys Overland in the United States of America. Bench testing revealed defects which required rectification, delaying completion of production drawings. Despite the delays one of the first flight-ready Arabs flew in a Martinsyde F.2 two-seat fighter/reconnaissance aircraft in mid 1917.
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
;Bedouin
;Kaffir
;Dyak
;Pathan
;Malay

Applications

Data from Brew.