title: ABC Scorpion
text: # ABC Scorpion
  
  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
  
  * 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
  * 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
  
  ### 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)
  