Rolls-Royce Exe

The Rolls-Royce Exe, or Boreas, was a 24-cylinder air-cooled X block sleeve valve aircraft engine intended primarily for the new Fairey Fleet Air Arm aircraft, particularly the Fairey Barracuda. The Exe was under development in 1939, having been started in the 1930s, along with the Peregrine and Vulture. The Exe was named after the River Exe, although Rolls-Royce later transferred the using of river names to its gas turbine engines.

Work on the Exe was suspended in August 1939, and stopped about August 1940. In August 1940 Hives wanted to stop work on the Peregrine, Exe and Vulture to concentrate on the Merlin and Griffon engines.

Applications
Originally intended for the Fairey Barracuda the Exe was only test flown in a Fairey Battle, the first flight taking place on 30 November 1938. This aircraft continued in use for some time as a communications aircraft where the Exe was noted to be quite reliable in service.