de Havilland Gipsy Twelve / Gipsy King

The de Havilland Gipsy Twelve was a British V-12, piston aero engine developed by the de Havilland Engine Company and first run in 1937. Approximately 95 were manufactured. It was known as the Gipsy King in Royal Air Force service.

Applications:
de Havilland DH.91 Albatross
de Havilland DH.93 Don

Specifications:

Gipsy King I
Type: Inverted 60 degree V-12 inline piston engine
Bore: 4.646 in (118 mm)
Stroke: 5.512 in (140 mm)
Displacement: 1121.3 cu in (18.3 L)
Length: 82.6 in (2,098 mm)
Width: 31.5 in (800 mm)
Height: 37.4 in (950 mm)
Dry weight: 1,058 lb (480 kg)
Valvetrain: Overhead valve
Supercharger: Single speed
Fuel type: 87 Octane petrol
Cooling system: Air cooled
Reduction gear: Spur geared, reduction ratio 0.667:1
Power output: 425 hp at 2,450 rpm at 0 psi boost (five minutes maximum)
Compression ratio: 6:1
Power-to-weight ratio: 0.4 hp/lb