Armstrong Siddeley Heritage Trust
Armstrong Siddeley Genet Major & Civet Aero-Engine
The name "Genet Major" has caused confusion since its introduction. This is due to the existence of two versions: a five-cylinder engine and a seven-cylinder variant. To further complicate matters, the Royal Air Force renamed their version of the seven-cylinder engine the Civet. In explanation, this simple list should help:
The Genet Major Mk I was a five-cylinder radial engine.
The Genet Major Mk IA to IV was a seven-cylinder radial engine.
The Civet, the Royal Air Force name for the Genet Major IA.
Armstrong Siddeley Seven Cylinder Genet Major
Avro 616 Avian credit B Dannecker
Southern Martlet Genet Major I Credit Shuttleworth Trust
Leading Particulars of Genet Major Engines
Mk I
Engine Type 5-cylinder, single-row, radial, air-cooled, poppet-valve engine
Bore 4.25 inch (108 mm)
Stroke 4.5 inch (114.3 mm)
Volume 319.32 cu. in. (5.2 litre)
1929 105hp (77.23kW) Direct Drive. Compression ratio 5.35:1
MkIA & Civet
Engine Type 7-cylinder, single-row, radial, air-cooled, poppet-valve engine
Bore 4.25 inch (108 mm)
Stroke 4.5 inch (114.3 mm)
Volume 452 cu. in. (7.3 litre)
1936 145hp (106.64kW) Direct Drive. Compression ratio of 5:1
Production Variants
Mk III Same as the MkIA with a Compression ratio of 5.25:1
MK IV Same as the MkIII, but with a geared epicyclic drive
