Bentley BR2

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.

Design and development
The initial variant of the BR.2 developed 230 hp, with nine cylinders measuring 5.5 x for a total displacement of 1,522 cubic inches (24.9 L). It weighed 490 lb, only 93 lb 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.

Variants

 * BR.2 230
 * 1918, 230 hp.


 * BR.2 245
 * 1918, 245 hp.

Applications

 * Airco DH.6
 * Armstrong Whitworth Armadillo
 * Austin Osprey
 * Boulton Paul Bobolink
 * Gloster Grouse
 * Gloster Nightjar
 * Gloster Sparrowhawk
 * Grain Griffin
 * Handley Page Type S
 * Nieuport Nightjar
 * Sopwith Camel
 * Sopwith Buffalo
 * Sopwith Gnu
 * Parnall Panther
 * Sopwith Salamander
 * Sopwith Snipe
 * Vickers Vampire

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.