View source for BMW M70

{{Infobox automobile engine
| image         = BMW 850 V12.JPG
| name          = BMW M70 engine
| production    = 1987–1994
| configuration = 60° [[V12 engine|V12]]
| valvetrain    = [[Overhead camshaft#Single overhead camshaft|SOHC]]
| displacement  = {{convert|4988|cc|L|1|order=flip|abbr=on}}
| bore          = {{convert|84|mm|2|abbr=on}}
| stroke        = {{convert|75|mm|2|abbr=on}}
| block         = Aluminium
| head          = Aluminium
| power         = {{convert|220|kW|0|abbr=on}}
| torque        = {{convert|450|Nm|lbft|0|abbr=on}}
| fueltype      = [[Petrol engine|Petrol]]
| predecessor   = None
| successor     = [[BMW M73]]
}}
The [[BMW]] '''M70''' is a [[Naturally aspirated engine|naturally-aspirated]], [[Overhead camshaft#Single overhead camshaft|SOHC]], [[V12 engine|V12]] [[petrol engine]], which was BMW's first production V12<ref>{{cite web|title=BMW E32 parts|url=http://www.usautoparts.net:80/bmw/models/e32.htm|website=www.usautoparts.net|access-date=4 August 2017|archive-url=https://web.archive.org/web/20130703041906/http://www.usautoparts.net/bmw/models/e32.htm|archive-date=3 July 2013|url-status=dead}}</ref> and was produced from 1987 to 1996. It was also the first German 12-cylinder post-war automobile engine, predating [[Mercedes-Benz M120 engine|Mercedes-Benz's M120]] by four years and VAG's [[Volkswagen Group W-12 engine|W12]] by fourteen.
The BMW '''S70/2''' engine, largely unrelated to the M70 and S70B56 engines, is a naturally-aspirated, [[Overhead camshaft#Dual overhead camshaft|DOHC]], V12 petrol engine, which powered the 1993 to 1998 [[McLaren F1]].
==Design==
The M70's design is similar to that of two 2.5 L [[BMW M20|M20]] straight-six engines joined at a 60-degree angle,<ref>{{cite web|title=The 8-Series Was One Of BMW's Best Failed Experiments|url=http://jalopnik.com/the-8-series-was-one-of-bmws-best-failed-experiments-1585763392|website=www.jalopnik.com|date=5 June 2014 |access-date=30 July 2017}}</ref> due to the following features: [[Overhead camshaft#Single overhead camshaft|single overhead camshaft]] valvetrain, bore spacing of {{convert|91|mm|in|1|abbr=on}}, [[bore (engine)|bore]] of {{convert|84|mm|in|2|abbr=on}}, [[stroke (engine)|stroke]] of {{convert|75|mm|in|2|abbr=on}}, and a [[compression ratio]] of 8.8:1.<ref>{{cite web|title=1989 BMW 750i E32 Specification|url=http://www.carfolio.com/specifications/models/car/?car=14322|website=www.carfolio.com|access-date=4 August 2017}}</ref>
The M70 has the following differences with the M20 engine:
* Aluminium alloy engine block ([[Alusil|AluSil]]) instead of cast-iron (both engines have an aluminium [[cylinder head]]), to reduce weight.<ref>{{cite web|title=BMW M70, M72 and M73 V12 Engines|url=http://www.unixnerd.demon.co.uk/m70.html|website=www.unixnerd.demon.co.uk|access-date=4 August 2017|archive-date=7 January 2016|archive-url=https://web.archive.org/web/20160107232007/http://www.unixnerd.demon.co.uk/m70.html|url-status=dead}}</ref>
* Airflow measurement using [[Mass air flow sensor]]s (MAFs)<ref>{{cite web|title=7' E32 750iL Mass air flow sensor|url=http://www.realoem.com/bmw/en/showparts?id=GC81-EUR-02-1987-E32-BMW-750iL&diagId=13_1379|website=www.realoem.com|access-date=30 July 2017}}</ref> instead of [[Air flow meter]]s (AFMs) to improve fuel economy.
* [[Electronic throttle control|Electronic Throttle Control]] instead of a mechanical throttle cable.
* A [[timing chain]] was used instead of a [[timing belt (camshaft)|timing belt]],<ref>{{cite web|title=7' E32 750iL Timing and valve train-timing chain|url=http://www.realoem.com/bmw/en/showparts?id=GC81-EUR-02-1987-E32-BMW-750iL&diagId=11_1190|website=www.realoem.com|access-date=30 July 2017}}</ref> to reduce servicing requirements.
* [[Hydraulic tappet|Hydraulic valve lifters]] instead of mechanically adjusted tappets, to reduce servicing requirements.
The M70 has two [[Motronic#1.3|Motronic 1.3]]<ref name="Motronic">{{cite web|url=https://kfzdiag.de/mediafiles/Verwendungslisten/BMW.pdf|title=BMW|access-date=1 February 2019|archive-date=2 February 2019|archive-url=https://web.archive.org/web/20190202212921/https://kfzdiag.de/mediafiles/Verwendungslisten/BMW.pdf|url-status=dead}}</ref> [[engine control unit|ECUs]] (one for each cylinder bank). To provide redundancy, the M70 also has two fuel pumps, fuel rails, distributors, mass air flow sensors, crankshaft position sensors, coolant temperature sensors and throttle bodies.<ref>{{cite web|title=V12 (M70) Regular Maintenance|url=http://bmwe32.masscom.net/sean750/v12_cross_referencing/v12regularMaintanance.htm|website=www.bmwe32.masscom.net|access-date=4 August 2017}}</ref>
Some M70 engines (such as fitted to the [[BMW E32|E32]] 750iL Highline) are fitted with two [[alternator]]s. The second alternator is smaller and is used to charge an auxiliary battery and power equipment in the rear passenger compartment, such as a telephone, fax machine, wine cooler, independent climate control and power sun shields.<ref>{{cite web|title=Engines Exposed: Just How Far Has BMW's Beastly V12 Come?|url=http://www.carbuzz.com/news/2016/2/5/Engines-Exposed-Just-How-Far-Has-BMW-s-Beastly-V12-Come-7731822/|website=www.carbuzz.com|date=5 February 2016|access-date=30 July 2017}}</ref>
== Versions ==
{|class="wikitable sortable"
|-
!Version !!Displacement!!Power!!Torque!!Redline!!Years
|-
![[#M70B50|M70B50]]
|{{convert|4988|cc|cuin|1|abbr=on}} || {{convert|220|kW|0|abbr=on}}<ref>{{cite web |title=BMW M70B50 V12-Zylinder-Ottomotor |url=https://bmw-grouparchiv.de/research/detail/index.xhtml?id=3942614 |website=bmw-grouparchiv.de |access-date=6 February 2021}}</ref> <br /> at 5,200 rpm ||{{convert|450|Nm|lbft|0|abbr=on}} <br /> at 4,100 rpm ||6,000|| 1987–1994
|-
![[#S70B56|S70B56]]
|{{convert|5576|cc|cuin|1|abbr=on}}||{{convert|280|kW|0|abbr=on}} <br /> at 5,300 rpm || {{convert|550|Nm|lbft|0|abbr=on}} <br /> at 4,000 rpm ||6,400|| 1992–1996
|-
![[#S70/2|S70/2]]
|{{convert|6064|cc|cuin|1|abbr=on}}||{{convert|461|kW|0|abbr=on}} <br /> at 7,400 rpm || {{convert|617 or 651 |Nm|lbft|0|abbr=on}} <br /> at 6,700 rpm ||7,500||1993–1998
|-
![[#S70/3|S70/3]]
|{{convert|5990|cc|cuin|1|abbr=on}}||{{convert|467|kW|0|abbr=on}} <br /> at 6,500 rpm{{efn|S70/3 specifications are for the race car with twin {{convert|32.9|mm|2|abbr=on}} air restrictors,<ref name="Le Mans '99">{{cite web |title=Le Mans '99 |url=https://bmw-grouparchiv.de/research/detail/index.xhtml?id=3418176 |website=bmw-grouparchiv.de |access-date=9 June 2019}}</ref> as required by 24 Hours of Le Mans rules at the time.<ref>{{cite web |title=Diamètre des brides / Air rectrictors diameter |url=http://lemans-history.com/regulamentos/1998/1998_anexe_a.pdf |website=lemans-history.com |access-date=9 June 2019}}</ref> }} ||{{convert|670|Nm|lbft|0|abbr=on}} <br /> at 4,500 rpm ||8,000||1998–2000
|}
{{notelist}}
===M70B50===
Applications:
*1987–1994 [[BMW 7 Series (E32)|E32]] 750i/750iL – this was mated primarily to an automatic [[ZF 4HP24 transmission]]
*1989–1994 [[BMW 8 Series (E31)|E31]] 850i/850Ci – this was mated to either the automatic [[ZF 4HP24 transmission]] or the optional [[Getrag#Products#Longitudinal orientation#560G|Getrag 560G]]
* 1988 [[Alpina B12]]
*1991 [[BMW Nazca C2|BMW Nazca M12]]
*1992 [[BMW Nazca C2]]
== S70 engine {{Anchor|S70}}==
{{Infobox automobile engine
| name = BMW S70 engine
| image = 1996 McLaren F1 engine.jpg
| caption = Engine bay of a [[McLaren F1]]
| production = 1992–2000
| configuration = 60° [[V12 engine|V12]]
| block = Aluminium
| head = Aluminium
| displacement = {{convert|5576|cc|L|1|order=flip|abbr=on}}<br />{{convert|6064|cc|L|1|order=flip|abbr=on}}<br />{{convert|5990|cc|L|1|order=flip|abbr=on}}
| bore = {{convert|86|mm|2|abbr=on}}
| stroke = {{convert|80|mm|2|abbr=on}}<br />{{convert|87|mm|2|abbr=on}}<br />{{convert|85.9|mm|2|abbr=on}}
| valvetrain = [[Overhead camshaft#Dual overhead camshaft|DOHC]]
| compression = 11:1
| fueltype = [[Petrol engine|Petrol]]
| coolingsystem = [[Water cooling|Water-cooled]]
| power = {{convert|280-671|kW|0|abbr=on}}*(*900 PS produced only McLaren F1 GTR Long Tail specifically in full race trim upon qualification without racing restrictors)<ref>{{cite web|url=https://www.motorauthority.com/news/1110784_mclaren-f1-gtr-longtail-stretches-its-legs-at-spa-francorchamps|title = McLaren F1 GTR Longtail stretches its legs at Spa-Francorchamps}}</ref><ref>{{cite web|url=https://www.supercars.net/blog/1997-mclaren-f1-gtr-long-tail/|title = 1997 McLaren F1 GTR Long Tail &#124; McLaren|date = 18 April 2016}}</ref><ref>[https://www.motor1.com/news/16037/rare-race-spec-mclaren-f1-gtr-long-tail-found-on-sale/ ]{{dead link|date=August 2022}}</ref><ref>{{cite web  |url=https://www.carscoops.com/2020/06/street-legal-mclaren-f1-gtr-longtail-has-rich-history-15-million-asking-price/ |title=Street-Legal McLaren F1 GTR Longtail Has Rich History, $15 Million Asking Price |publisher=Carscoops |date=2020-06-18 |accessdate=2022-08-12}}</ref>
| torque = {{convert|550-900|N.m|lb.ft|0|abbr=on}}
| weight = {{convert|265|kg|lb|0|abbr=on}}
| predecessor = None
| successor = None
}}
===S70B56===
The first engine to use the S70 name is a {{convert|5576|cc|cuin|1|abbr=on}} variant of the M70 engine fitted only to the E31 850CSi.<ref>{{cite web|title=Engine specifications for Motorsport engines|url=http://www.bmwheaven.com/database/engine.php?type=Motorsport#/167|website=www.bmwheaven.com|access-date=4 August 2017}}</ref> With 1,510 units produced, this is the lowest production BMW engine to date.<ref>{{cite web|title=Worldwide Shipments: S70 850CSi 1992–1996|url=http://www.8coupe.com/Production/WorldwideShipments/S70850CSi19921996.aspx|website=www.8coupe.com|access-date=4 August 2017}}</ref>
Three prototype [[Overhead camshaft#Dual overhead camshaft|dual overhead camshaft]] S70 engines were constructed, prior to the decision to not produce an E31 M8 model.<ref>{{cite web|title=BMW S70 and S70/2 V12 Engines|url=http://www.unixnerd.demon.co.uk/s70.html|website=www.unixnerd.demon.co.uk|access-date=4 August 2017|archive-date=19 August 2017|archive-url=https://web.archive.org/web/20170819052831/http://www.unixnerd.demon.co.uk/s70.html|url-status=dead}}</ref>
Applications:
* 1992–1996 [[BMW 8 Series (E31)|E31]] 850CSi
* 1993 [[BMW Nazca C2|BMW Nazca C2 Spider]]
* 2011 [[Lavazza Automotive|Simbol Design Lavazza GTX-R]] (twin-turbo version)
===S70/2===
The S70/2, while sharing the same 12 cylinder layout, bore spacing and design principle as the S70B56, is essentially a new design with the heads based on the European market [[BMW S50|S50B30]],<ref>{{cite web|title=BMW Classic – Recherche-Client|url=https://bmw-grouparchiv.de/research/detail/index.xhtml?id=3943376|website=bmw-grouparchiv.de|access-date=28 February 2018}}</ref> and thus featuring 4 valves per cylinder and [[variable valve timing]] (called [[VANOS]] by BMW) and individual throttle bodies. A [[dry sump]] oiling system is used.<ref>{{cite web|title=1994 McLaren F1: First Drive Flashback|url=http://www.roadandtrack.com/new-cars/first-drives/reviews/a5339/performance-tests-first-drives-flashback-1994-mclaren-f1/|website=Road & Track|date=14 December 2014|access-date=4 May 2017}}</ref> The weight of the S70/2, plus ancillaries and full exhaust, is {{convert|265|kg|lb|0|abbr=on}}.<ref>{{cite web|title=F1 – McLaren's Road Car An Autocar & Motor Book|url=http://www.audiosignal.co.uk/McLarenF1.html|website=www.audiosignal.co.uk|access-date=4 August 2017}}</ref>
Applications:
* 1993–1998 [[McLaren F1]]
===S70/3===
The S70/3 is a racing engine based on the S70/2.
Applications
* 1998–1999 [[BMW V12 LM]] racing car
* 1999–2000 [[BMW V12 LMR]] racing car
* 2000 [[BMW X5 (E53)#X5 LM|BMW X5 LM]] concept car<ref>{{cite web|url=https://www.motor1.com/news/501344/bmw-x5-le-mans-video/|title = BMW Shows the X5 le Mans Concept and Its V12 Engine with 700+ HP}}</ref><ref>{{cite web|url=https://www.caranddriver.com/reviews/a15139465/bmw-x5-on-the-ring-car-news/|title=2001 BMW X5 le Mans Concept Had the V-12 Heart of a McLaren F1|date=16 June 2020}}</ref><ref>{{cite web|url=https://www.bmw-m.com/en/topics/magazine-article-pool/the-bmw-x5-le-mans.html|title = The BMW X5 le Mans}}</ref>
==See also==
* [[BMW Goldfish V16]]
==References==
{{reflist|30em}}
{{commons category|BMW M70 engine}}
{{BMW automotive petrol engines: 1960s to 1980s}}
[[Category:BMW engines|M70]]
[[Category:V12 engines]]
[[Category:Gasoline engines by model]]