The de Havilland Gipsy Twelve was a British aero engine developed by the de Havilland Engine Company in 1937. Approximately 95 were manufactured. It was known as the Gipsy King in Royal Air Force service.

• de Havilland DH.91 Albatross
• de Havilland DH.93 Don

Preserved de Havilland Gipsy Twelve engines are on public display at the following museums:

• de Havilland Aircraft Museum
• London Science Museum.

Data from Lumsden^[1]

• Type: Inverted 60 degree V-12 piston engine
• Bore: 4.646 in (118 mm)
• Stroke: 5.512 in (140 mm)
• Displacement: 1121.3 cu in (18.4 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

Comparable engines

• Alfa Romeo 122
• Argus As 410
• Isotta Fraschini Gamma
• Junkers Jumo 210
• Ranger V-770
• Renault 12R
• Walter Sagitta

Related lists

• List of aircraft engines

• Photo of a de Havilland Gipsy Twelve at Enginehistory.org