BMW M337

{{Infobox automobile engine |name=BMW M337 |image=BMW 501 (5444397631).jpg |caption=BMW 501- the first car to use the M337 |production=1952-1958 |configuration= [[straight-six engine|Straight-6]] |displacement={{convert|2.0|-|2.1|L|cuin|0|abbr=on}} |valvetrain=[[overhead valve engine|OHV]] |block=Cast iron |head=Cast iron |fueltype=[[Petrol engine|Petrol]] |predecessor=[[BMW M78]] |successor= }}

The [[BMW]] '''M337''' is a [[straight-six engine|straight-6]] [[overhead valve engine|OHV]] petrol engine installed at a slanted angle which was produced in three variants (M337/1, M337/2 and M337/3) from 1952-1958. Built to power BMW's first new car after World War II, the M337 engine was a replacement for the [[BMW M78]].

== Design == Compared with its M78 predecessor, the M337 features a revised [[cylinder head]], a new [[inlet manifold]] and a reinforced [[crankshaft]] with bigger, more modern bearings.<ref name="Norbye">{{cite book |last=Norbye |first=Jan P. |title=BMW - Bavaria's Driving Machines |year=1984 |publisher=Publications International |location=Skokie, IL |isbn=0-517-42464-9 |url-access=registration |url=https://archive.org/details/bmwbavariasdrivi00norb }}</ref>{{refpage|page=88}}<ref name="DeutscherSportverlag">{{cite magazine | date = 20 March 1953 |title = BMW 501 | magazine = Auto- und Motorrad-Welt | publisher = Deutscher Sportverlag Kurt Stoof | location = Köln | language = de }}</ref> As per the M78, the M337 has an iron [[engine block]], an iron [[cylinder head]] and [[overhead valve engine|overhead valves]] with two valves per cylinder.<ref name="noakes ultimate history">{{cite book|last1=Noakes|first1=Andrew|title=The Ultimate History of BMW|date=2008|publisher=Parragon Books|isbn=978-1-4075-3512-8}}</ref>{{refpage|page=46}}

== Versions == {|class="wikitable" style="text-align: center;" |- ! Model !! Displacement !! Power !! Torque !! Year |- |M337/1 || rowspan=2|{{convert|1971|cc|cuin|1|abbr=on}} || {{convert|48|kW|PS hp|0|abbr=on}} at 4,400 rpm || {{convert|129|Nm|lbft|0|abbr=on}} at 2,000 rpm|| 1952-1954 |- |M337/2 || rowspan=2|{{convert|54|kW|PS hp|0|abbr=on}} at 4,400 rpm || {{convert|130|Nm|lbft|0|abbr=on}} at 2,500 rpm || 1954-1955 |- |M337/3 || {{convert|2077|cc|cuin|1|abbr=on}} || {{convert|135|Nm|lbft|0|abbr=on}} at 2,500 rpm || 1955-1958 |}

=== M337/1 === The first version of the M337 engine has a displacement of {{convert|1971|cc|cuin|1|abbr=on|order=flip}}. It produces {{cvt|48|kW|PS|0}} at 4,400 rpm and {{convert|129|Nm|lbft|abbr=on}} at 2,000 rpm.<ref name="6enligne">{{cite web|url=http://www.6enligne.net/html/modeles/fiche_moteur.php3?idMoteur=15 |title=BMW M337 |website=www.6enligne.net |url-status=dead |archive-url=https://web.archive.org/web/20120611124634/http://www.6enligne.net/html/modeles/fiche_moteur.php3?idMoteur=15 |archive-date=11 June 2012}}</ref>

Applications: * 1952-1954 [[BMW 501|501]]

=== M337/2 === In 1954, a revised engine was released which produced {{cvt|54|kW|PS|0}} at 4,400 rpm and {{convert|130|Nm|lbft|0|abbr=on}} at 2,500 rpm.<ref name="Norbye"/><ref name="6enligne" /><ref name="noakes ultimate history"/>{{refpage|page=48}} The compression ratio for this engine is 6.8:1.

Applications: * 1954-1955 [[BMW 501#Development of the BMW 501|501A]] * 1954-1955 [[BMW 501#Development of the BMW 501|501B]]

=== M337/3 === The final version of the M337 had an increase in [[bore (engine)|bore]] of {{convert|2|mm|in|abbr=on}}, which increased displacement to {{convert|2077|cc|cuin|1|abbr=on}}. The [[compression ratio]] was also increased to 7.0:1. Despite these changes the M337/3 produced no more power than the previous version. However torque increased to {{convert|135|Nm|lbft|0|abbr=on}} at 2,500 rpm.<ref name="Norbye"/>{{refpage|page=92}}<ref name="6enligne" />

Applications: * 1955-1958 [[BMW 501#Development of the BMW 501|501/3]]

==References== {{reflist|30em}}

[[Category:BMW engines|M337]] [[Category:Straight-six engines]] [[Category:Slant engines]] [[Category:Gasoline engines by model]] [[Category:1950s automobile engines]]