Napier Sabre IIA Horizontally-Opposed 24 Engine

Type: Reciprocating, 24 cylinders, Horizontally opposed, Supercharged, Water cooled

Power rating: 1,641 kW (2,200 hp) at 3,700 rpm

Displacement: 36.7 L (2,240 cu in.)

Bore and Stroke: 127 mm (5.00 in.) x 121 mm (4.75 in.)

Weight: 1,071 kg (2,360 lb)

geared drive; supercharged; sleeve valves; missing starter, generator, spark plugs; on stand.

With an industrial history dating to the early nineteenth century, D. Napier and Son became famous for its automobiles. It began building aircraft engines in the World War I era. The highly successful Napier Lion, a water cooled W-12 configuration, first ran in 1917 and ended production in 1943.

Napier’s unusual H-shaped engines were originally designed in 1928 with 16 air cooled cylinders. Proposed in 1935, first run in 1937 and type tested in 1940, the Sabre was intended for high-altitude fighters. This liquid cooled H-shaped configuration was essentially comprised of four 6-cylinder engines, twin crankshafts, and combined gearing. Early problems with the engine's sleeve valves resulted in engine seizures, but these were resolved with improved metallurgy and manufacturing methods. Poor maintenance also caused early operational problems.

During World War II, the Sabre IIA powered the Folland Fo.108 43/37, Hawker Tempest V, and Hawker Typhoon I and IB.