title: Franklin O-805
text: # Franklin O-805
  
  The Franklin O-805 (company designation 12AC) was an American air-cooled aircraft piston engine, designed in the mid-1940s and was to be used in radio-controlled pilotless drones that were to be guided from an accompanying control plane. Due to project requirement changes and cancellations the engine was not produced.
  
  A smaller displacement 12-cylinder Franklin engine of 1941 was known as the O-595 or 12AC-596.
  
  ## Variants
  
  ### O-805
  
  **12AC-806**
  
  
      450 hp (336 kW)0
  
  **12ACG-806 (XO-805-1)**
  
  
      456 hp (340 kW) at 3,200 rpm, geared to 0.632:1.
  
  **12ACGSA-806 (XO-805-3 and O-805-5)**
  
  
      500 hp (373 kW) at 3,200 rpm, supercharged and geared to 0.632:1 (XO-805-3), or to 0.587:1 (O-805-5).
  
  ### O-595
  
  **12AC-596**
  
  
      300 hp (224 kW) at 2,600 rpm
  
  **12ACG-596**
  
  
      350 hp (261 kW) at 3,500 rpm
  
  ## Applications (intended)
  
  * Interstate XBQ-5
  * Interstate XTD2R-1
  
  ## Survivors
  
  * There is an O-805-2 on display at the New England Air Museum, Bradley International Airport, Windsor Locks, CT
  * One surfaced and was sold privately in August, 2016, on eBay for US$8500.
  
  ## Specifications (12ACGSA-806/XO-805-3)
  
  ### General characteristics
  
  * Type: 12-cylinder air-cooled horizontally opposed aircraft piston engine
  * Bore: 4.625 in (117.5 mm)
  * Stroke: 4.0 in (101.6 mm)
  * Displacement: 806.4 cu in (13.2 L)
  
  ### Components
  
  * Valvetrain: OHV
  * Cooling system: Air-cooled
  * Reduction gear: 0.632
  
  ### Performance
  
  * Power output: 500 hp (373 kW) at 3,200 rpm
  