Bentley BR1

The Bentley BR.1 was a British rotary aircraft engine of the First World War. Designed by the motor car engine designer W. O. Bentley, the BR.1 was built in large numbers, being one of the main powerplants of the Sopwith Camel.

History

The 130 hp Clerget 9B was an important engine for the British Royal Naval Air Service and Royal Flying Corps, being license produced in Britain and powering a number of important British aircraft, including the Sopwith Camel. It was, however expensive, at £907 a copy, and prone to overheating, so the Admiralty asked Lieutenant W. O. Bentley, an established pre-war engine designer, to produce a modified version to solve these problems cite book |last= Gunston|first=Bill |authorlink=Bill_Gunston |title= The Development of Piston Engines|year= 1999|publisher= Patrick Stephens |location= Sparkville, Somerset|edition= Second edition|isbn=1 85260 599 5 ] .

Bentley came up with an engine fitted with aluminium cylinders with cast iron liners, and aluminium pistons. Dual ignition was introduced to improve reliability, and the stroke increased to 6.7 in, which allowed power to be increased to 150 hp cite book |last= Gunston|first=Bill |authorlink=Bill_Gunston |title=World Encyclopedia of Aero Engines |year=1986 |publisher= Guild Publishing|location=London |isbn= ] . The cost of the engine was also reduced, falling to £605 per engine .

The resulting engine, initially known as the A.R.1 for "Admiralty Rotary", but later called the BR.1 ("Bentley Rotary") was manufactured in quantity, initially against Admiralty orders. It was standardised for the Camel in RNAS squadrons, but unfortunately there were never enough to entirely replace the inferior and more expensive Clerget engine in British service, and most RFC Camel squadrons continued to use Clerget engines, in fact licenced production of the Clerget continued.

The BR.1 was developed as the BR.2, a heavier, more powerful engine, which powered, among other types or aircraft, the Camel's eventual replacement, the Sopwith Snipe.

Applications

* Sopwith Camel
* Avro 536
* Westland N.1B
* Port Victoria P.V.9

pecifications

Data from Jane's Fighting Aircraft of World War I cite book |title= Jane's Fighting Aircraft of World War I |year= 2001 |publisher=Random House |location= London|isbn= 1 85170 347 0|pages= p.274 ] pistonspecs

type=9 Cylinder air cooled rotary engine
bore=4.7 in, 120 mm
stroke=6.7 in, 170 mm
displacement=1,055 cu in, 17.3 L
length=
diameter=
width=
height=
weight=397 lb, 180 kg
valvetrain=
supercharger=
turbocharger=
fuelsystem=
fueltype=
oilsystem=
coolingsystem=
power=150 bhp, 112 kW at 1250 rpm
specpower=
compression=
fuelcon= 13.2 US gallon/hr, 50 L/hr (11 Imperial gallon/hr)
specfuelcon=
oilcon= 1.8 US Gallon/hr, 6.8 L/hr(12 Imperial pints/hr)
power/weight=2.67 lb/bhp

References

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