See the Napier Sabre V aero engine in 360º in the Virtual Archive

D Napier and Son was a British engineering company best known for its work on engines, initially for road vehicles and later for aircraft.

A decline in car sales during the 1920s led Napier to concentrate its efforts on aero engines. Napier employed Frank Halford, an aircraft designer, to assist with engine development. Halford developed an interest in the improvements made to engine performance through the use of a sleeve valve mechanism as an alternative to the standard poppet valve. Halford’s interest in the sleeve valve led to the design of a horizontally opposed 24-cylinder sleeve-valved H-configuration liquid-cooled petrol engine which was named the Sabre. 

The first iteration of the Sabre was tested in 1938, achieving 1,350hp. In June 1940 the engine passed the Air Ministry’s 100-hour test, achieving 2,200hp. 

The Sabre V engine was produced in 1944 and was the last version to enter operational service. It was able to consistently achieve 2,400hp.

In 1946 D Napier and Son donated to the IMechE a 1:4-sized model of the Sabre V engine. This model can be viewed in 360° in the Virtual Archive.