Franklin 12 series / 12AC / O-805

Franklin 12

The Franklin 12 series of 12-cylinder air-cooled horizontally opposed aircraft engines produced in the 1940s and 50s, (US military designation O-805 was applied to the 12AC-806, 12ACG-806 and 12ACGSA-806).

The Franklin O-805 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.

Variants:

12AC-596
300 hp (224 kW) @ 2,600 rpm.

12ACG-596
350 hp (261 kW) @ 3,500 rpm.

12AC-806
450 hp (336 kW)0

12ACG-806
456 hp (340 kW) @ 3,200 rpm, geared to 0.632:1, (XO-805-1).

12ACGSA-806
500 hp (373 kW) @ 3,200 rpm, supercharged and geared to 0.632:1 (XO-805-3), or to 0.587:1 (O-805-5).

O-805
Military designation of the 12AC-806, 12ACG-806 and 12ACGSA-806.

 
Franklin O-805

Applications (intended):
Interstate XBQ-5
Interstate XTD2R-1

Specifications

O-805-2
Type: 12-cylinder air-cooled horizontally opposed aircraft piston engine
Displacement: 805 cu. in.
Cooling system: Air-cooled
Power output: 450 hp