Scorpion
ABC Scorpion I on display at the Shuttleworth Collection
Type	Flat-twinaero 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]

Scorpion I

1923, 30 hp (22 kW)

Scorpion II

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

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

Data fromLumsden^[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)

Comparable engines

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

Related lists

• List of aircraft engines