Sunbeam Engines: Maori
Note: This is a sub-section of Sunbeam: Sunbeam-Coatalen.
A direct development of the Afrida
In similar fashion to Louis Coatalens development of Sunbeam's 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 (748.8 cu in) for a power output of 260 hp (194 kW)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 250 hp (186 kW)at 2,000rpm, whilst new-build Maori Mk.IIs were rated at 260 hp (194 kW)at 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 (205 kW).
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.