ABC Scorpion

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.

Variants

Scorpion I: 1923, 30 hp (22 kW)
Scorpion II: 1924, 34 hp (25 kW), increased bore and stroke.

Applications

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

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)

References

Notes

↑ Gunston 1989, p.9.
↑ 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.

[1] Gunston 1989, p.9.

[2] Lumsden 2003, p.54.