View source for Volkswagen air-cooled engine

{{Short description|German automotive engine}}
{{Use dmy dates|date=August 2021}}
{{Use American English|date=July 2021}}
<!-- specifications are for the "first" Volkswagen engine, not the 985&nbsp;cc KdF engine -->
{{Infobox automobile engine
|name          = <big>Volkswagen Boxer Engine</big>
|manufacturer  = [[Volkswagen]]
|aka           =
|production    = 1936–2006
| displacement =  {{ubl |{{cvt|985|cc|L|1|order=flip}}|{{cvt|1131|cc|L|1|order=flip}}|{{cvt|1192|cc|L|1|order=flip}}|{{cvt|1285|cc|L|1|order=flip}}|{{cvt|1493|cc|L|1|order=flip}}|{{cvt|1584|cc|L|1|order=flip}}|{{cvt|1679|cc|L|1|order=flip}}|{{cvt|1795|cc|L|1|order=flip}}|{{cvt|1971|cc|L|1|order=flip}} }}
|bore          = {{ubl |{{cvt|70|mm|2}}|{{cvt|75|mm|2}}|{{cvt|77|mm|2}}|{{cvt|83|mm|2}}|{{cvt|85.5|mm|2}}|{{cvt|90|mm|2}}|{{cvt|93|mm|2}}<br>{{cvt|94|mm|2}} }}
|stroke        = {{ubl |{{cvt|64|mm|2}}|{{cvt|69|mm|2}}{{cvt|66|mm|2}}|{{cvt|71|mm|2}} }}
|successor     = [[Volkswagen Wasserboxer engine]]
|configuration = [[flat-four engine|Flat-4]] [[naturally aspirated engine|naturally aspirated]] [[petrol engine]]
}}

The '''Volkswagen air-cooled engine''' is an [[Air-cooled engine|air-cooled]], [[gasoline]]-fuelled, [[boxer engine]] with four horizontally opposed cast-iron [[cylinder (engine)|cylinder]]s, cast aluminum alloy [[cylinder head]]s and [[piston]]s, [[magnesium]]-alloy [[crankcase]], and forged steel [[crankshaft]] and [[connecting rod]]s.

There are two distinct families/variations of the aircooled engine, namely Type 1 and Type 4. The Type 3 engine is a variation of the Type 1 engine with a pancake cooling arrangement.

Variations of the engine were produced by [[list of Volkswagen Group factories|Volkswagen plants]] worldwide from 1936 until 2006 for use in Volkswagen's own vehicles, notably the [[Volkswagen Type 1|Type 1 (Beetle)]], [[Volkswagen Type 2|Type 2 (transporter)]], [[Volkswagen Type 3|Type 3]], and [[Volkswagen Type 4|Type 4]]. Additionally, the engines were widely used in industrial, light aircraft and kit car applications.

==Type 1: 1.0–1.6 litres{{anchor|T1}}==

{{Infobox automobile engine
|name          = Volkswagen Type 1 Engine
|manufacturer  = [[Volkswagen]]
|aka           = Type 3 engine (when equipped with a crank mounted cooling fan)
|production    = 1936-2006
|successor     = [[#Type 4: 1.7-2.0 litres|Volkswagen Type 4 engine]]
|configuration = [[flat-four engine|Flat-4]] [[naturally aspirated engine|naturally aspirated]] [[petrol engine]]
|block         = Aluminum / [[magnesium]] alloy
|head          = Aluminum alloy
|valvetrain    = [[overhead valve|Pushrod OHV]]
|fuelsystem   = Mechanical / Carbureted / Digifant EFI (Mexico and U.S. Type 3 only)
|fueltype     = Gasoline
|oilsystem    = [[Wet sump]]
|coolingsystem = [[air-cooled engine|Air-cooled]]
}}

The Type 1 engine got its name from the [[Volkswagen Beetle|Type 1 Beetle]] it originally came with. It evolved from the original 985&nbsp;cc in the KdF wagen in 1939 to the 1600&nbsp;cc dual port fuel-injected engine that came in the 2003 Mexican Beetle. The very last Type 1 engine came in the 2006 [[Volkswagen Type 2#T2c|Type 2c]] built in Brazil. In most applications, the Type 1 engine came with an upright cooling shroud and a belt driven fan.

When equipped with crank mounted cooling fan, the Type 1 engine may be referred as ''Type 3 engine''. These engines came only in 1500&nbsp;cc and 1600&nbsp;cc configurations in [[Volkswagen Type 3]] based vehicles. The Type 1 engine was also used in [[Volkswagen Type 2|Type 2]] vehicles with additional engine mounting provisions. The term "universal engine case" refers to an engine case that can be used for all three applications. All Type 1 engines used lighter magnesium alloy for the engine case even though late model engines used stronger alloys for durability. The bore spacing on Type 1 engine is 112&nbsp;mm. 

A re-design of the Type 1 engine was introduced in 1968 in the [[Volkswagen Type 4]]. It came to be known as the [[Volkswagen_air-cooled_engine#Type_4:_1.7–2.0_litres|''Type 4 engine'']]. It was larger and more powerful and shared almost nothing with the Type 1 engine other than the general architecture of the longblock.

===1000===
*1938–1942<ref>"''Der Käfer – Eine Dokumentation Band 2''" by A. Etzold, published by Motorbuch, Stuttgart in 1985
{{ISBN|3-7168-1613-2}}</ref><ref>"''Das große Buch der Volkswagen-Typen''" by Lothar Boschen, published by Motorbuch, Stuttgart in 1983 {{ISBN|3-87943-799-8}}</ref> [[Volkswagen Beetle|KdF-Wagen]]
*1941–1942 [[Volkswagen Kübelwagen]]

{{Infobox automobile engine
|name          = <small>Volkswagen 1000 engine</small>
|production    = 1938–1942<!--Dates for the 1000 engine-->
|displacement  = {{cvt|985|cc|1|lk=on}}
|bore          = {{cvt|70|mm|2}}
|stroke        = {{cvt|64|mm|2}}
|fuelsystem    = <!--Which type/make/model of carburetor-->
|power         = {{cvt|18|kW|PS bhp|0|lk=on}} at 3,000&nbsp;rpm,<br>{{cvt|22|kW|PS bhp|0}}
|compression   = 5.8:1
}}

===1100===
{{Infobox automobile engine
|name          = <small>Volkswagen 1100 engine</small>
|image         = Volkswagen motor cut 1945.JPG
|caption = Cutaway 1945 1131&nbsp;cc engine
|aka           = 1100 engine
|production    = 1945–1953<!--Dates for the 1100 engine-->
|displacement  = {{cvt|1131|cc|1|lk=on}}
|bore          = {{cvt|75|mm|2}}
|stroke        = {{cvt|64|mm|2}}
|fuelsystem    = <!--Which type/make/model of carburetor-->
|power         = {{cvt|18|kW|PS bhp|0|lk=on}} at 3,300&nbsp;rpm,<br>{{cvt|22|kW|PS bhp|0}}
|specpower     = {{cvt|15.9|kW|PS bhp|0}} / L (18kW variant)
|torque        = {{cvt|68|Nm|0|lk=on}} at 2,000&nbsp;rpm
|compression   = 5.8:1
}}

Like the [[Volkswagen Beetle]] produced after the war, the first [[Volkswagen Transporter]]s (bus) used the Volkswagen air-cooled engine, a 1.1&nbsp;litre, [[Deutsches Institut für Normung|DIN]]-rated 18&nbsp;kW (24 PS, 24&nbsp;bhp), air-cooled four-cylinder [[flat engine|"boxer" engine]] mounted in the [[rear-engine design|rear]]. The 22-kilowatt (29 PS; 29&nbsp;bhp) version became standard in 1955, while an unusual early version of the engine which developed 25 kilowatts (34 PS; 34&nbsp;bhp) debuted exclusively on the [[Volkswagen Type 2 (T1)]] in 1959.

*1942–1944 [[Volkswagen Schwimmwagen]]
*1942–1945 [[Volkswagen Kübelwagen]], [[Volkswagen Beetle|Volkswagen KdF-Wagen]]
*1945–1953 [[Volkswagen Beetle]]
*1950–1953 [[Volkswagen Type 2]]

===1200===
{{Infobox automobile engine
|name          = <small>Volkswagen Typ 1200</small><ref name="Betriebsanleitung" />
|image         = VW Boxer 1192cm3.jpg
|aka           = 1200 Engine
|production    = 1950–1991<!--Dates for the 1200 engine-->
|displacement  = {{cvt|1192|cc|1|lk=on}}
|bore          = {{cvt|77|mm|2}}
|stroke        = {{cvt|64|mm|2}}
|length        =
|width         =
|height        =
|diameter      =
|weight        =
|fuelsystem    = Carburettor<br />Solex 28 PCI or Solex 28 PICT
|power         = {{cvt|22|kW|PS bhp|0|lk=on}}<br>{{cvt|25|kW|PS bhp|0}}<br>{{cvt|27|kW|PS bhp|0}}<br>{{cvt|30|kW|PS bhp|0}}
|specpower     = {{cvt|18.5|-|21.0|kW|PS bhp|0}} / L
|torque        = depending on engine application, around ~70–80&nbsp;N·m
|compression   = 7.0:1 – 7.3:1
|fuelcon       =
|fueltype      = Carburettor fuel<br />86 RON (7:1 compression ratio)<br />87 RON (7,3:1 compression ratio)
|specfuelcon   =
|oilcon        =
}}

The 1.2-litre engine is called ''Type 122'' and has a displacement of {{cvt|1192|cc}}.<ref name="Betriebsanleitung">''Die Betriebsanleitung für den Volkswagen-Industriemotor Typ 122, Typ 126A.'' Volkswagen AG. Wolfsburg. March 1985. Page 29</ref> As industrial engine, its rated power is {{cvt|22.8|kW|PS bhp|0}} at 3000&nbsp;min<sup>−1</sup> without a [[Governor (device)|governor]], the highest torque {{cvt|81.4|Nm|0}} at 2000&nbsp;min<sup>−1</sup>. With a governor set to 8% accuracy, the rated power is {{cvt|21.33|kW|bhp PS|0}} at 3000&nbsp;min<sup>−1</sup>, the highest torque is {{cvt|69.63|Nm|0}} at 2000&nbsp;min<sup>−1</sup>.<ref name="Nachtrag">''[http://www.motor-talk.de/forum/aktion/Attachment.html?attachmentId=699799 Änderungen nach August 1965].'' Nachtrag zur Betriebsanleitung des Industriemotors. August 1966</ref> For other applications, the power and torque output may vary, e.g. On the Beetle produced {{cvt|41|PS|bhp kW|0}} at 3900&nbsp;rpm and {{cvt|88|Nm|0}} of torque at 2400&nbsp;rpm.<ref>{{cite web|url=https://www.conceptcarz.com/s7533/Volkswagen-Beetle.aspx|website=conceptcarz|title=1963 Volkswagen Beetle Technical Specifications and Dimensions|access-date=29 October 2018}}</ref>

===1300===
{{Infobox automobile engine
|name          = <small>Volkswagen 1300 engine</small>
|production    = 1966–1995<!--Dates for the 1300 engine-->
|displacement  = {{cvt|1285|cc|1|lk=on}}
|bore          = {{cvt|77|mm|2}}
|stroke        = {{cvt|69|mm|2}}
|fuelsystem    = <!--Which type/make/model of carburettor-->
}}

1285&nbsp;cc 
Single port 1966, type 1, beetle only.
With Higher compression, it developed 50 bhp. It was a problematic engine, and so only used in the North American market in type 2 vehicles for model year 1966.

* 1966 [[Volkswagen Beetle]] (Europe, North America)
* 1966-70 [[Volkswagen Beetle]] (Europe, Non-USA)
* 1966 [[Volkswagen Type 2|Type 2]] (North America)
* 1971-73 [[Volkswagen Type 2|Type 2]] (Non USA) AB Engine code
* 1971-72 Non USA Low octane markets AC Engine code

==Type 4: 1.7–2.0 litres{{anchor|T4}}==
From 1968 to 1983, the Type 4 engine was produced in 1.7, 1.8 and 2.0 litre variants.<ref>{{cite web|url=https://motor-car.net/vw-engines/item/13796-vw-type-4-engine |title=VW Type 4 engine (1968-1983) |website=motor-car.net |access-date=17 June 2023}}</ref>

==Other applications==
Beginning in 1987, Dunn-Right Incorporated of Anderson, South Carolina, US has made a kit to perform the conversion of a VW engine to a compressor.<ref>{{cite web|url=http://www.dunnrightinc.com|title=Dunn-Right Incorporated|date=n.d.|access-date=16 January 2010}}</ref>

===Industrial===
[[Volkswagen Group|Volkswagen AG]] has offered these air-cooled boxer engines for use in [[Industrial sector|industrial]] applications since 1950, lately under its [[Volkswagen Industrial Motor]] brand. Available in {{convert|18|kW|PS bhp|0|lk=on}}, {{convert|22|kW|PS bhp|0}}, {{convert|25|kW|PS bhp|0}}, {{convert|31|kW|PS bhp|0}}, {{convert|33|kW|PS bhp|0}} and {{convert|46|kW|PS bhp|0}} outputs, from displacements of {{convert|1.2|L|cuin|0}} to {{convert|1.8|L|cuin|0}}, these Industrial air-cooled engines were officially discontinued in 1991.{{Citation needed|date=November 2012}}

===Aircraft===
[[File:AeroConversions AeroVee Engine.jpg|thumb|right|[[AeroConversions AeroVee Engine]]]]

The air-cooled opposed four-cylinder Beetle engines have been used for other purposes as well. [[Limbach Flugmotoren]] has since 1970 produced more than 6,000 aircraft engines based on the Beetle engine.<ref name="TC L2400">[http://easa.europa.eu/document-library/type-certificates/easae084], Limbach L2400</ref><ref name="TC L2000">[http://easa.europa.eu/document-library/type-certificates/easae083], Limbach L2000</ref><ref name="Type Certification L1700">[http://easa.europa.eu/document-library/type-certificates/easae082], Limbach L1700</ref><ref name="Limbach">[http://www.limflug.de/ Limbach], Limbach Aero Engines</ref> Sauer has since 1987 produced certified engines for small airplanes and motorgliders,<ref name="Carat">[http://www.ams-flight.si/index.php?option=com_content&view=article&id=93&Itemid=92&lang=en Carat motorglider], Carat motorglider.</ref> and is now also producing engines for the ultralight community in Europe.<ref name="Sauer">[http://www.sauer-flugmotorenbau.de/Flugmotore.html Sauer Flugmotorenbau], Sauer Flugmotorenbau.</ref><ref name="Groppo">[http://www.spriteaviation.co.uk/Sprite_Aviation_2/Sauer.html Sauer in Groppo] {{webarchive|url=https://web.archive.org/web/20140416183150/http://www.spriteaviation.co.uk/Sprite_Aviation_2/Sauer.html |date=16 April 2014 }}, Sauer in Groppo.</ref>

This type of VW engine deployment started separately in Europe and in the US. In Europe this started in France soon after the [[Second World War]] using the engine in the [[Volkswagen Kübelwagen]] that were abandoned by the thousands in the country side<ref name="Monnett" /> and peaked with the JPX engine.<ref name="JPX">[http://www.jpx.fr/Jpx/english/pg_4tx90E.htm JPX], JPX</ref> In the US this started in the 1960s when VW Beetle started to be imported.<ref name="Monnett">[http://www.eaavideo.org/video.aspx?v=3367045529001 EAA Webinar John Monnett], John Monnett.</ref> A number of companies still produce [[aero engine]]s that are Volkswagen Beetle engine derivatives: Limbach, Sauer, Hapi, Revmaster, [[Great Plains Type 1 Front Drive]], Hummel, the [[AeroConversions AeroVee Engine]], and others. [[Kit planes]] or plans built experimental aircraft were specifically designed to utilize these engines. The VW air-cooled engine does not require an expensive and often complex gear reduction unit to utilize a propeller at efficient cruise RPM{{huh|date=December 2024}}. With its relative low cost and parts availability, many experimental aircraft are designed around the VW engines.<ref>{{cite news |title=In North Kitsap, Turning Old Cars into New Planes |newspaper=Kitsap Sun |date=29 November 2009}}</ref><ref>[http://www.greatplainsas.com/2010Iss3.pdf Great Plans Aircraft Newsletter, Issue 3, 2010.]</ref>

[[Formula V Air Racing]] uses aircraft designed to get maximum performance out of a VW powered aircraft resulting in race speeds above 160&nbsp;mph.<ref>[http://www.formulav.com/ Formula V Air Racing]</ref>

Some aircraft that use the VW engine are:
[[File:Volkswagen engine Volksplane.JPG|thumb|Volkswagen air-cooled engine installed in an [[Evans VP-1 Volksplane]]]]
{{columns-list|colwidth=22em|
*[[Aerosport Quail]]
*[[Airdrome Bleriot Model XI]]
*[[Airdrome Dream Fantasy Twin]]
*[[Airdrome Fokker DR-1]]
*[[Airdrome Fokker D-VI]]
*[[Airdrome Fokker D-VII]]
*[[Airdrome Fokker D-VIII]]
*[[Airdrome Nieuport 11]]
*[[Airdrome Nieuport 24]]
*[[Airdrome Taube]]
*[[AirLony Skylane]]
*[[Airmotive EOS 001]]
*[[Akaflieg München Mü23 Saurier]]
*[[Altair Coelho AC-11]]
*[[Alvarez Polliwagen]]
*[[Aurore MB 04 Souris Bulle]]
*[[Bensen B-8]]
*[[BK Fliers BK-1]]
*[[Bounsall Super Prospector]]
*[[Boyd G.B.1]]
*[[Bradley Aerobat]]
*[[Cassutt Special]]
*[[Circa Reproductions Nieuport 11]]
*[[Circa Reproductions Nieuport 17]]
*[[Corby Starlet]]
*[[Denney Kitfox]]
*[[Druine Turbulent]]
*[[Evans VP-1 Volksplane]]
*[[Evans VP-2 Volksplane]]
*[[Falconar F9A]]
*[[Falconar F11 Sporty]]
*[[Fisher Avenger V]]
*[[Fisher Youngster]]
*[[Flaglor Sky Scooter]]
*[[Flitzer Z-21]]
*[[Great Plains Easy Eagle]]
*[[Grob G 109]]
*[[Harmon Der Donnerschlag]]
*[[Harmon Mister America]]
*[[Hummel H5]]
*[[Hummel Ultracruiser Plus]]
*[[JDT Hi-MAX]]
*[[JPM 01 Médoc]]
*[[Junqua Ibis]]
*[[Just Superstol]]
*[[Mignet Pou-du-Ciel]]
*[[Mini-Hawk Tiger-Hawk]]
*[[Mini-MAX|JDT V-MAX]]
*[[Kolb M3X]]
*[[Leger Pataplume 1]]
*[[Light Miniature Aircraft LM-5]]
*[[Milholland Legal Eagle]] – half VW and full Type 1 VW engines
*[[Monnett Sonerai]]
*[[Nicollier Menestrel]]
*[[Parker Jeanie's Teenie]]
*[[Parrish Dart]]
*[[Pazmany PL-4A]]
*[[Plumb BGP-1]]
*[[Pober Pixie]]
*[[Pottier P.40]]
*[[Pottier P.130 Coccinelle]]
*[[Preceptor STOL King]]
*[[Preceptor Ultra Pup]]
*[[Preceptor Stinger]]
*[[QAC Quickie Q2]]
*[[RagWing RW1 Ultra-Piet]] – half VW and full Type 1 VW engines
*[[RagWing RW7 Duster]] – half VW and full Type 1 VW engines
*[[Rand Robinson KR-1]]
*[[Rand Robinson KR-2S]]
*[[Scheibe Falke]]
*[[Sisler SF-2A Cygnet]]
*[[Sonex Aircraft Onex]]
*[[Sonex Aircraft Sonex]]
*[[Southern Aeronautical Renegade]]
*[[Southern Aeronautical Scamp]]
*[[Stewart Headwind]]
*[[Stolp SA-500 Starlet]]
*[[Taiwan Dancer TD-3]]
*[[Tervamäki ATE-3]]
*[[Tipsy Nipper]]
*[[Taylor Monoplane]]
*[[Thatcher CX4]]
*[[Vidor Champion V]]
*[[Viking Dragonfly]]
*[[Zenair CH 100]]
}}

====Half VW====
[[File:Hummelbird Amateur Built C-FPKY 05 half VW engine.JPG|thumb|Half Volkswagen engine mounted in a [[Hummel Bird]]]]

For aircraft use, a number of experimenters, who were seeking a small, two-cylinder, four-stroke engine, began cutting Type 1 VW engine blocks in half, creating a two-cylinder, horizontally opposed engine. The resulting engine produces {{cvt|30|to|38|hp|kW|0}}. Plans and kits have been made available for these conversions.<ref name="BetterHalf">{{cite web|url = http://www.betterhalfvw.com/engine.htm|title = The Better Half VW Engine – Engine Detail|access-date = 26 May 2010|last1 = Millholland|first1 = L. E. |last2 = Gibson |first2 = Graeme|date=November 2002}}</ref><ref name="GPA">{{cite web|url = https://www.greatplainsas.com/carr-twin-plans-plus-shipping.aspx|title = 0058 / Carr Twin Plans|last = Great Plains Aircraft Supply Co., Inc.|date = n.d.|access-date=16 February 2022}}</ref>

One such conversion is the ''Carr Twin'', designed by Dave Carr, introduced in January 1975, in the [[Experimental Aircraft Association]]'s ''Sport Aviation'' magazine. The design won the John Livingston Award for its outstanding contribution to low cost flying and also was awarded the Stan Dzik Memorial Award for outstanding design.<ref name="GPA" />

Other examples include the [[Total Engine Concepts MM CB-40]] and [[Better Half VW]].

Some aircraft that use the Half VW engine are:
{{columns-list|colwidth=30em|
*[[Belite Ultra Cub]]
*[[Duane's Hangar Ultrababy]]
*[[Hummel Bird]]
*[[Hummel Ultracruiser]]
*[[Milholland Legal Eagle]] – half VW and full Type 1 VW engines
*[[Pop's Props Pinocchio]] 
*[[Preceptor N3 Pup]] 
*[[RagWing RW1 Ultra-Piet]] – half VW and full Type 1 VW engines
*[[RagWing RW4 Midwing Sport]]
*[[RagWing RW7 Duster]] – half VW and full Type 1 VW engines
*[[Spacek SD-1 Minisport]]
*[[Ultravia Pelican]]
}}

==References==
{{Reflist}}
{{Refbegin}}
*{{cite web|url=http://beetle.cabriolets.online.fr/tech/evolution.html#Engine|title=The Evolution of the Beetle|work=Exklusively Käfer Kabrioletts|publisher=Beetle.Cabriolets.online.fr|access-date=16 January 2010}}
{{Refend}}

{{Volkswagen Group brands}}
{{VW}}
{{Volkswagen Commercial Vehicles}}

{{DEFAULTSORT:Volkswagen Air Cooled Engine}}
[[Category:Volkswagen Group engines|Air cooled]]
[[Category:Boxer engines]]
[[Category:Lists of automobile engines]]
[[Category:1930s aircraft piston engines]]