Bentley BR2

BR.2
	Preserved Bentley BR.2

The Bentley BR.2 was a British rotary aircraft engine developed during the First World War by the motor car engine designer W. O. Bentley from his earlier Bentley BR.1. Coming as it did near the end of the war, the BR.2 was built in smaller numbers than the earlier BR.1 – its main use being by the Royal Air Force in the early 1920s.^[1]

Design and development[]

The initial variant of the BR.2 developed 230 horsepower (170 kW), with nine cylinders measuring 5.5 by 7.1 inches (140 mm × 180 mm) for a total displacement of 1,522 cubic inches (24.9 L). It weighed 490 pounds (220 kg), only 93 pounds (42 kg) more than the BR.1.

The Sopwith Snipe, selected as the standard single-seat fighter of the post-war RAF was designed around the BR.2 – it was also used by the ground attack version of the Snipe, the Sopwith TF-2 Salamander.

This was the last type of rotary engine to be used by the RAF – later air-cooled aircraft engines being almost entirely of the fixed radial type. The BR.2 represented the peak of rotary engine development.^[2]

Variants[]

BR.2 230: 1918, 230 hp.
BR.2 245: 1918, 245 hp.

Applications[]

Engines on display[]

A Bentley BR.2 is on public display in the Science Museum (London), another forms part of the aero engine collection at the Royal Air Force Museum Cosford.

A ¼ scale working replica of the Bentley BR.2 World War I rotary aero engine built by Lewis Kinleside Blackmore is currently on display at the Bentley Memorial Building in Oxfordshire, UK. This was the first model built of this engine and is the subject also of a book by L K Blackmore.

Specifications (BR.2)[]

BentleyBR2(Plate) — Manufacturer's plate (dated November 1917) and valve operating gear of the BR.2 engine on display at the Royal Air Force Museum Cosford

Data from Jane's ^[3]

General characteristics

Type: 9-cylinder rotary
Bore: 5.51 in (140 mm)
Stroke: 7.09 in (180 mm)
Displacement: 1521.8 in (24.94 L)
Dry weight: 490 lb (220 kg)

Components

Valvetrain: Overhead valve
Cooling system: Air-cooled

Performance

Power output: 250 hp
Fuel consumption: 20 gallons per hour
Oil consumption: 16 pints per hour
Power-to-weight ratio: 0.5 hp/lb

References[]

Notes[]

↑ Lumsden 2003, p.88.
↑ Gunston 1989, p.22.
↑ Jane's 1993, p.274.

Bibliography[]

Gunston, Bill (1986). World Encyclopedia of Aero Engines. Wellingborough: Patrick Stephens. pp. 25–26.
Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9
Jane's Fighting Aircraft of World War I. London. Studio Editions Ltd, 1993. ISBN 1-85170-347-0
Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.

External links[]

Wikimedia Commons has media related to Bentley BR2.

National Museum of the USAF - BR.2 fact sheet

All or a portion of this article consists of text from Wikipedia, and is therefore Creative Commons Licensed under GFDL.
The original article can be found at Bentley BR2 and the edit history here.

[1] Lumsden 2003, p.88.

[2] Gunston 1989, p.22.

[3] Jane's 1993, p.274.

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