ABC Scorpion

Scorpion
ABC Scorpion I on display at the Shuttleworth Collection
Type	Flat-twin aero engine
National origin	United Kingdom
Manufacturer	ABC Motors
Designer	Granville Bradshaw
First run	1921

The ABC Scorpion is a 30 hp (22 kW) two-cylinder aero engine designed by British engineer Granville Bradshaw for use in light aircraft. The engine was built by ABC Motors Limited and first ran in 1921.[1]

Variants

Scorpion I

1923, 30 hp (22 kW)

Scorpion II

1924, 34 hp (25 kW), increased bore and stroke.

Applications

Scorpion II installed in an ANEC II at the Shuttleworth Collection

• ABC Robin
• Boulton Paul Phoenix
• BFW M.19
• BFW M.23
• Comper Swift
• de Havilland Humming Bird
• Farman Moustique
• Hawker Cygnet
• Heath Parasol
• Hendy Hobo
• Henderson-Glenny Gadfly
• Kay Gyroplane
• Luton Minor
• Mignet HM.14 Pou-du-Ciel
• Parmentier Wee Mite
• Peyret-Mauboussin PM X
• RWD 1
• SAI KZ I
• Saynor & Bell Canadian Cub
• Short Satellite
• Snyder Buzzard
• Udet U 7 Kolibri
• Wheeler Slymph^[citation needed]
• Westland Woodpigeon

Survivors

The only ANEC II (G-EBJO) flies regularly at the Shuttleworth Collection at Old Warden and is powered by a Scorpion II.

Specifications (Scorpion I)

Data from Lumsden [2]

General characteristics

• Type: 2 cylinder air cooled flat-twin
• Bore: 3.6 in (87.5 mm)
• Stroke: 3.7 in (91.5 mm)
• Displacement: 73.32 cu in (1.1 L)
• Dry weight: 90 lb (41 kg)

Components

• Valvetrain: Overhead valve, two valves per cylinder
• Fuel system: Carburettor
• Fuel type: 74 Octane petrol
• Cooling system: Air

Performance

• Power output: 30 hp (22 kW) at 2,750 rpm
• Compression ratio: 4:1
• Power-to-weight ratio: 0.33 hp/lb (0.53 kW/kg)

See also

Comparable engines

• Aeronca E-113
• Armstrong Siddeley Ounce
• Bristol Cherub
• Haacke HFM-2
• Walter Atom

Related lists

• List of aircraft engines

References

Notes

1. Gunston 1989, p.9.
2. Lumsden 2003, p.54.

Bibliography

• Gunston, Bill. World Encyclopedia of Aero Engines. Cambridge, England. Patrick Stephens Limited, 1989. ISBN 1-85260-163-9
• Guttery, T.E. The Shuttleworth Collection. London: Wm. Carling, 1969. OCLC 19614929
• Lumsden, Alec. British Piston Engines and their Aircraft. Marlborough, Wiltshire: Airlife Publishing, 2003. ISBN 1-85310-294-6.