<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. --> {{infobox aero engine |name= O-405/6AC-403 |image = |caption = |engine_type= [[Piston]] [[aircraft engine]] |national_origin = United States |manufacturer= [[Franklin Engine Company]] |first_run= 1942 |major_applications= |number_built = |developed_from = |developed_into = |variants_with_their_own_articles = }}
The '''Franklin O-405''' (company designation '''6AC-403''') was an American air-cooled aircraft engine of the 1940s. The engine was of [[Flat-six engine|six-cylinder, horizontally-opposed layout]] and [[Engine displacement|displaced]] {{convert|405|cuin|L|abbr=on|2}}. The power output was between {{convert|200|hp|kW|abbr=on|0}} and {{convert|250|hp|kW|abbr=on|0}} depending on variant. The '''O-405-9 (6ACV-403)''' was a vertically mounted, fan cooled version for helicopters.
==Variants== ;6AC-403 (XO-405-1):{{convert|200|hp|kW|abbr=on|0}} at 2,750 rpm
;6ACSA-403 (XO-405-3):Supercharged, {{convert|220|hp|kW|abbr=on|0}} at 2,750 rpm
;6ACGSA-403 (O-405-5): Supercharged, geared propeller drive at 0.632:1. {{convert|250|hp|kW|abbr=on|0}} at 3,200 rpm
;6ACV-403 (O-405-9):Vertically mounted, fan-cooled helicopter version, {{convert|245|hp|kW|abbr=on|0}} at 3,275 rpm
==Applications== *[[Culver XPQ-15]] *[[Sikorsky R-6|Doman LZ-1A]] *[[Doman Pelican]] *[[Fairchild 24|Fairchild XUC-86B]] *[[Fleetwings XBQ-1]] *[[Kellett XR-8]] *[[Sikorsky R-6]]
==Specifications (6AC-403/XO-405-1)== {{pistonspecs |<!-- If you do not understand how to use this template, please ask at [[Wikipedia talk:WikiProject Aircraft]] --> <!-- Please include units where appropriate (main comes first, alt in parentheses). If data are missing, leave the parameter blank (do not delete it). For additional lines, end your alt units with </li> and start a new, fully-formatted line with <li> --> |ref={{fact|date=December 2017}} |type=6-cylinder air-cooled [[flat-6|horizontally opposed]] aircraft piston engine |bore=4.625 in (117.5 mm) |stroke=4.0 in (101.6 mm) |displacement=403.2 in³ (6.6 L) |length= |diameter= |width= |height= |weight=405 lb (184 kg) |valvetrain= |supercharger= |turbocharger= |fuelsystem= |fueltype= |oilsystem= |coolingsystem=Air-cooled |power=200 hp (149 kW) at 2,750 rpm |specpower= |compression= |fuelcon= |specfuelcon= |oilcon= |power/weight= }}
==See also== {{aircontent <!-- include as many lines are appropriate. additional lines/entries with carriage return. --> |see also= |related= |similar engines= *[[Continental Tiara series|Continental Tiara 6-260]] |similar aircraft=<!-- similar or comparable aircraft --> |lists=<!-- related lists --> *[[List of aircraft engines]] }}
==References==
;Notes {{reflist}} ;Bibliography {{refbegin}} * Gunston, Bill. (1986) ''World Encyclopedia of Aero Engines''. Patrick Stephens: Wellingborough. p. 57 {{refend}}
{{Franklin aeroengines}} {{US military piston aeroengines}}
[[Category:Franklin aircraft engines]] [[Category:1940s aircraft piston engines]] [[Category:Boxer engines]] [[Category:Six-cylinder engines]] [[Category:Air-cooled aircraft piston engines]]