View source for Franklin O-335

{{Short description|Aircraft piston engine}}
{{Use mdy dates|date=January 2022}}
{{Use American English|date=January 2022}}
{{more footnotes|date=December 2017}}
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{|{{Infobox Aircraft Begin
|name=  O-335/6A/6V
|image = FranklinO335engine1.JPG
|caption =
}}
{{Infobox Aircraft Engine
|type= [[Flat-6]]
|national origin = United States
|manufacturer= [[Franklin Engine Company]]
|first run=
|major applications= [[Bell 47]], [[Hiller OH-23 Raven]]
|number built =
|developed from =
|developed into =
|variants with their own articles =
}}
|}
The '''Franklin O-335''' (company designations variations on '''6A''' and '''6V''') 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|335|cuin|L|abbr=on|1}}. The power output of later variants was {{convert|225|hp|kW|abbr=on|0}}.
==Design and development==
These engines were commonly vertically mounted and used to power many early helicopters in the United States. They were closely related to the [[Franklin 2A4|2A4]] and [[Franklin 4A4|4A4]] 2- and 4-cylinder engines. In various subtypes, the 6A4 remained in continuous production from 1945 to the time Franklin's United States operations ceased in 1975, with versions continuing in Polish production into the 1990s.
In 1947 this engine was modified into a [[water-cooled]] version by the [[Preston Tucker|Tucker Car Corporation]] for use in the [[1948 Tucker Sedan]].  Tucker liked the engine so much that he purchased the Aircooled Motors/[[Franklin Engine Company]], and it remained under the ownership of the Tucker family until 1961.
==Variants==
;O-335-1:Military designation of vertical installation model for helicopters :{{convert|175|hp|kW|abbr=on|0}}
;O-335-3:Similar to -1 but changes in starter installation
;O-335-5:{{convert|200|hp|kW|abbr=on|0}}
;O-335-5B:{{convert|200|hp|kW|abbr=on|0}}
;6A-335:{{convert|180|hp|kW|abbr=on|0}} at 2,800 rpm
;6AL-335:{{convert|150|hp|kW|abbr=on|0}} at 2,600 rpm
;6A4-125:{{convert|125|hp|kW|abbr=on|0}} at 2,200 rpm
;6A4-130:{{convert|130|hp|kW|abbr=on|0}} at 2,200 rpm
;6A4-135:{{convert|135|hp|kW|abbr=on|0}} at 2,450 rpm
;6A4-140:{{convert|140|hp|kW|abbr=on|0}} at 2,375 rpm
;6A4-145:{{convert|145|hp|kW|abbr=on|0}} at 2,600 rpm
;6A4-150:{{convert|150|hp|kW|abbr=on|0}} at 2,600 rpm
;6A4-165:{{convert|165|hp|kW|abbr=on|0}} at 2,800 rpm
;6A4-200:{{convert|200|hp|kW|abbr=on|0}} at 3,100 rpm
;6AG-335:{{convert|220|hp|kW|abbr=on|0}} at 3,400 rpm
;6AG4-185:{{convert|185|hp|kW|abbr=on|0}} at 3,100  rpm
;6AGS-335:{{convert|260|hp|kW|abbr=on|0}} at 3,400 rpm
;6AS-335:{{convert|240|hp|kW|abbr=on|0}} at 3,200 rpm
;6V-335-B:{{convert|210|hp|kW|abbr=on|0}} at 3,100 rpm
;6V-335-A1A:{{convert|200|hp|kW|abbr=on|0}} at 3,100 rpm
;6V-335-A1B:{{convert|200|hp|kW|abbr=on|0}} at 3,100 rpm
;6V4-165:{{convert|165|hp|kW|abbr=on|0}}
;6V4-178-B32:{{convert|178|hp|kW|abbr=on|0}} at 3,000 rpm
;6V4-200-C32:{{convert|200|hp|kW|abbr=on|0}} at 3,100 rpm
;6VS-O-335:{{convert|225|hp|kW|abbr=on|0}} at 3,200 rpm
==Applications==
[[File:Stahls Automotive Collection December 2021 144 (1948 Tucker Sedan engine).jpg|thumb|A Franklin O-335 in a [[Tucker 48]] at [[Stahls Automotive Collection]]]]
{{columns-list|colwidth=30em|
* [[Aero-Flight Streak]]
* [[Aeronca Sedan]]
* [[Bartlett Zephyr]]
* [[Bell 47]]
* [[Bell H-13 Sioux]]
* [[Bellanca Cruisair]]
* [[Brantly B-1]]
* [[Goodyear Duck]]
* [[Hiller OH-23 Raven|Hiller H-23 Raven]]
* [[OH-23 Raven|Hiller 360]]
* [[Hirth Acrostar]]
* [[HTM Skytrac]]
* [[Maule M-5|Maule M-5-220C Lunar Rocket]]
* [[Republic RC-3 Seabee]]
* [[Seibel S-4]]
* [[Sikorsky S-52]]
* [[Socata Rallye|Socata MS.894 Rallye Minerva]]
* [[Stinson Voyager]]
* [[Sznycer SG-VI]]
* [[Taylorcraft 15]]
* [[Temco TE-1B]]
* [[Tucker (automobile)]]
* [[Temco T-35 Buckaroo|Temco YT-35 Buckaroo]]
}}
==Specifications (6AL-335 / 6A4-150-B3)==
[[File:FranklinO335Engine2.JPG|right|thumb|Franklin O-335/6AC Engine.]]
{{pistonspecs
|<!-- If you do not understand how to use this template, please ask at [[Wikipedia talk:WikiProject Aircraft]] -->
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|ref=''Wilkinson'' <ref name=Wilkinson>{{cite book|last=Wilkinson|first=Paul H.|title=Aircraft Engines of the world 1945|year=1945|publisher=Paul H. Wilkinson|location=New York|pages=80–81}}</ref>
|type=6-cylinder air-cooled [[flat-6|horizontally opposed]] direct drive supercharged aircraft piston engine
|bore={{convert|4.5|in|mm|abbr=on|1}}
|stroke={{convert|3.5|in|mm|abbr=on|1}}
|displacement={{convert|335|cuin|L|abbr=on|2}}
|length={{convert|37.4|in|mm|abbr=on}}
|diameter=
|width={{convert|30.8|in|mm|abbr=on}}
|height={{convert|21.6|in|mm|abbr=on}}
|weight={{convert|307|lb|kg|abbr=on}}
|valvetrain=OHV, 1 x inlet valve, 1 x exhaust valve operated by pushrods
|supercharger=Mechanically driven supercharger
|turbocharger=
|fuelsystem=1x [[Marvel-Schebler]] MA-3SPA updraught carburettor
|fueltype=80 [[Octane]] gasoline
|oilsystem=80 [[S.U. secs]] (15.6 [[Viscosity#Stokes_.28unit.29|cSt]]) grade pressure fed at {{convert|40|psi|bar|abbr=on|0}}, [[wet sump]]
|coolingsystem=Air-cooled
|power=<br/>
*(Take-off): {{convert|150|hp|kW|abbr=on}} at 2,600 rpm
*(Normal): {{convert|150|hp|kW|abbr=on}} at 2,600 rpm at sea level
*(Cruising): {{convert|112|hp|kW|abbr=on}} at 2,350 rpm at sea level
|specpower= 0.45 hp/(cu in) (20.35 kW/L)
|compression=7:1
|fuelcon=
|specfuelcon= 0.51 lb/(hp h) (0.311 kg/(kW h) cruising, 4.5 US gal/(hp h)) cruising
|oilcon=0.01 lb/(hp h) (0.006 kg/(kW h)
|power/weight=0.488 hp/lb (0.8 kW/kg)
|designer=
|reduction_gear=
|general_other=
|components_other=[[Delco-Remy]] direct cranking electric starter motor
|performance_other=
'''[[B.m.e.p.]]:''' {{convert|137|psi|kPa|abbr=on|0}}
}}
==See also==
{{aircontent
<!-- include as many lines are appropriate. additional lines/entries with carriage return. -->
|see also=
|related=
|similar engines=
*[[Lycoming O-435]]
|similar aircraft=<!-- similar or comparable aircraft -->
|lists=<!-- related lists -->
*[[List of aircraft engines]]
}}
==Notes==
{{reflist}}
==References==
{{Commons category}}
{{refbegin}}
* Gunston, Bill. (1986) ''World Encyclopedia of Aero Engines''. Patrick Stephens: Wellingborough. p.&nbsp;57
* Erickson, Jack. ''[http://home.comcast.net/~aeroengine/Franklin2.html Horizontally Opposed Piston Aero Engines]''
*{{cite book|last=Wilkinson|first=Paul H.|title=Aircraft Engines of the world 1945|year=1945|publisher=Paul H. Wilkinson|location=New York|pages=80–81}}
* US Department of Transportation Federal Aviation Administration Type Certificate Data Sheet E-238 Revision 12, December 8, 1994.
{{refend}}
{{Franklin aeroengines}}
{{US military piston aeroengines}}
[[Category:Boxer engines]]
[[Category:1940s aircraft piston engines]]
[[Category:Franklin aircraft engines]]