The Franklin O-405 (company designation 6AC-403) was an American air-cooled aircraft engine of the 1940s. The engine was of six-cylinder, horizontally-opposed layout and displaced 405 cu in (6.64 L). The power output was between 200 hp (149 kW) and 250 hp (186 kW) depending on variant. The O-405-9 (6ACV-403) was a vertically mounted, fan cooled version for helicopters.
|Type||Piston aircraft engine|
|National origin||United States|
|Manufacturer||Franklin Engine Company|
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