Rolls-Royce Vulture

The Rolls-Royce Vulture (and the related Peregrine) were aircraft engines, and probably the least successful power units ever produced by Rolls-Royce.

They were part of a program to develop power levels beyond that of the Merlin (1,100 hp, 820 kW) in the early production versions) - a program that also resulted in creations like the Napier Sabre.

The Peregrine was a fairly standard design (at first sight) with two cylinder banks arranged in a V form. The Vulture was basically two Peregrines joined at the crankcase and with separate crankshafts geared to a common propeller shaft thus putting the cylinder banks in an X layout.

Both seem to have suffered from a far too short pre-service development period and the reliability was very poor. So much so that production was stopped.

The only type using the Vulture to go into production was the Avro Manchester which had two of them. When the engine reliability issues became clear the Avro team re-designed the aircraft to use four Merlins. This was initially called the Manchester Mark III and then renamed Lancaster.