BMW M30 explained

BMW M30 engine
Production:	1968 - 1995
Configuration:	Straight-6
Valvetrain:	SOHC
Block:	Cast iron
Head:	Aluminium
Fueltype:	Petrol
Predecessor:	BMW M20
Successor:	BMW M50

The BMW M30 is a SOHC straight-six petrol engine which was produced from 1968 to 1995. With a production run of 27 years, it is BMW's longest produced engine and was used in many car models.

The first models to use the M30 engine were the BMW 2500 and 2800 sedans. The initial M30 models were produced in displacements of 24941NaN1 and 27881NaN1. Larger displacement versions were introduced over time, with the largest version being 34301NaN1, which was sometimes badged as "3.5 litres".^[1] As per the BMW M10 four-cylinder engine from which the M30 was developed, the M30 has an iron block, an aluminium head and an overhead camshaft with two valves per cylinder.

The engine was given the nicknames of 'Big Six' and 'Senior Six', following the introduction of the smaller BMW M20 straight-six engine in the late 1970s. The M30 was produced alongside the M20 throughout the M20's production, and prior to the introduction of the BMW M70 V12 engine in 1987, the M30 was BMW's most powerful and largest regular production engine.

Following the introduction of the BMW M50 engine in 1990, the M30 began to be phased out.

Ward's have rated the M30 as one of the "Top Engines of the 20th Century".^[2]

Design

The M30 was originally developed in the late 1960s, loosely based on the BMW M10 four-cylinder engine first used in the BMW New Class sedans and coupes. Initially, the engine code was "M06" and the "M68", until all versions began to use the "M30" prefix in 1981.^{[3] [4] [5]}

Common features between the M10 and M30 include a profile lowering 30-degree slant to the right, a crossflow cylinder head (a gas flow head in later designs) and chain-driven camshaft with rocker arm valve actuation.^[6] Further similarities include a cast-iron block with an aluminium head and a forged crankshaft. The first two M30 engines introduced were the and the versions, which both used an 862NaN2 bore.

M30B35LE/M90 engine

The M30B35LE engine, also called the M90, was used in several models from 1979-1982. It combines the block from the motorsports BMW M88 DOHC engine with the M30's SOHC cylinder head.

Versions

Version	Displacement	Power output	Torque	Year
M30B25V	24941NaN1	at 6,000 rpm	2110NaN0 at 3,700 rpm	1968
M30B25			2150NaN0 at 3,700 rpm	1981
M30B28V	27881NaN1	at 6,000 rpm	2350NaN0 at 3,700	1968
M30B28		1350NaN0 at 5,800 rpm	2400NaN0 at 4,200 rpm	1977
M30B30V	29861NaN1	at 6,000 rpm	2550NaN0 at 3,700 rpm	1971
M30B30		at 5,500 rpm	2720NaN0 at 4,300 rpm	1971
M30B32	32101NaN1	at 5,500 rpm	2850NaN0 at 4,300 rpm	1976
M30B33V	32951NaN1	1390NaN0 at 5,500 rpm	2890NaN0 at 3,500 rpm	1973
M30B34	34301NaN1	1600NaN0 at 5,800 rpm	3100NaN0 at 4,200 rpm		1982
M30B35		1550NaN0 at 5,700 rpm	3050NaN0 at 4,000 rpm	1988

M30B25V

The first 24941NaN1 version of the M30 was introduced in the 1968 E3 2500. This version uses dual Solex Zenith 35/40 INAT carburettors, has a compression ratio of 9.0:1 and produces 1100NaN0 in most applications.^[7] It has a bore of 86mm and a stroke of 71.6mm.

The M30B25 has previously been called the M06 and M68, prior to BMW retroactively renaming it the M30B25V (V for Vergaser- carburettor in German).^[8]

Applications:

• 1968–1977 E3 2500
• 1974–1975 E9 2.5 CS
• 1973–1976 E12 525 —,^[7] Solex 4A1 carburettor
• 1976–1981 E12 525
• 1977–1979 E23 725^[9]

M30B25

In 1981, Bosch L-Jetronic electronic fuel injection was added to the 24941NaN1 version. Peak power remained unchanged at 1100NaN0, however torque increased slightly to 2150NaN0.

Applications:

• 1981-1987 E28 525i^[10]
• 1981-1986 E23 725i^{[11] [12]}

M30B28V

In its original form, the carburetted 2.8 used two Solex Zenith "35/40 INAT" carburetors, the compression ratio is 9.0:1 and the engine produces and . The specifications went on to vary depending on the model year, carburettor and country. The bore is 86mm and the stroke is 80mm.

This version has also been known as the M06 and M68, prior to BMW renaming it the M30B28V.

Applications:

• 1968-1977 E3 2800 / 2.8L — ^{[13] [14]}
• 1968-1971 E9 2800 CS — 1250NaN0^[15]
• 1971-1971 E3 Bavaria — 168hp,^{[16] [17]} United States only
• 1974-1976 E12 528 — dual Zenith INAT carburettors^{[18] [19] [20]}
• 1976-1978 E12 528 —, Solex 4A1 carburettor^[21]
• 1977-1979 E23 728 —, Solex 4A1 carburettor^[22]

M30B28

In 1977, Bosch L-Jetronic electronic fuel injection was added to the 27881NaN1 version. Power increased to 1350NaN0 and torque increased to 2400NaN0.

• 1977-1978 E12 528i — North America only, 1290NaN0, 9.0:1 compression ratio
• 1978-1981 E12 528i — ^[23]
• 1979-1986 E23 728i
• 1979-1987 E24 628CSi
• 1981-1987 E28 528i^[24]

M30B30V

Based on the M30B28V version with a 3mm larger bore, the M30B30V produces and 2550NaN0,^{[25] [26]} uses dual Zenith 35/40 INAT carburettors and has a compression ratio of 9.0:1. In United States trim, this engine produced at 5800 rpm.^[27]

Applications:

• 1971-1975 E9 3.0 CS
• 1971-1972 E9 3.0 CSL
• 1971-1974 E3 3.0 S / 3.0 L / Bavaria
• 1976-1979 E24 630 CS —, Pierburg 4A1 carburetor^[28]
• 1977-1979 E23 730 —, Solex 4 A 1 carburettor^[29]

M30B30

The fuel injected version of the 29861NaN1 M30 debuted in 1971 in the E9 3.0 CSi and initially used the Bosch D-Jetronic mechanical fuel injection system.^[30] In 1976, the fuel injection system was upgraded to Bosch L-Jetronic electronic fuel injection.^[30] The M30B30 produces up to and,^[31] depending on the model year and whether a catalytic converter is fitted. The compression ratio is 9.2:1. With catalytic converter, compression ratio is 9:1.

Applications:

• 1971-1975 E9 3.0 CSi — ^[31]
• 1972-1973 E9 3.0 CSL —
• 1972-1975 E3 3.0 Si — 1470NaN0
• 1975-1978 E12 530i — North America only, 1310NaN0^[32]
• 1976-1976 E12 530 MLE — South Africa only, 1470NaN0^[33]
• 1977-1978 E24 630CSi — North America only, 1290NaN0^[34]
• 1986-1995 E32 730i — 1380NaN0^{[35] [36]}
• 1988-1990 E34 530i — 1380NaN0

M30B32

Despite having a capacity of 32101NaN1, this engine appeared in many cars badged so as to suggest 3.30NaN0 of displacement- such as the 633i, 3.3 Li, and 733i. The compression ratio is 8.8:1. In the E24 633CSi coupe, the M30B32 uses Bosch L-Jetronic electronic fuel injection. The US version used L-Jetronic from 1978 until mid-1981, changing over to Motronic digital fuel injection in June of that year. The 1979 732i is BMW's first use of Bosch's Motronic fuel injection.^[37] The bore is 89mm and the stroke is 86mm.

Applications:

• 1973-1975 E9 3.0 CSL —, 31531NaN1
• 1976-1984 E24 633CSi — 145or in Euro spec, NaN0NaN0 in USA spec
• 1976-1979 E3 3.3 Li — ^[38]
• 1977-1984 E23 733i — in Euro spec,^[39] NaN0NaN0 in USA spec
• 1979-1981 E12 533i — North America only, 1350NaN0^[40]
• 1979-1986 E23 732i — 1440NaN0
• 1982-1984 E28 533i — North America only,
• 1984-1986 E30 333i — South Africa only,, special ALPINA Intake plenum and exhaust manifold, modified L-Jetronic Injection. Only 210 (including six test cars) were produced for local Group 1 homologation.^[41]

M30B33V

The carburetted M30B33 produces and 2890NaN0.^[42] It has a bore of 89mm and a stroke of 88mm.

Applications:

• 1973-1975 E3 3.3 L^[43]

M30B34

The M30B34 engines sold in Europe and most other markets used a 10.0:1 compression ratio and produced .^[44] In North America and Japan, the M30B34 used an 8.0:1 compression ratio and produced .^[45] This engine was also offered in Europe from the latter half of 1985 until mid-1987. In all markets, the Bosch Motronic digital fuel injection system was used. The bore is 92mm and the stroke is 86mm.

Applications:

• 1982-1987 E23 735i / L7
• 1982-1987 E24 635CSi / L6 — in Euro spec
• 1985-1988 E28 535i / 535is / M535i

M30B35

This engine has a capacity of 34301NaN1, despite the "B35" model code. It produces at 5700 rpm and at 4000 rpm, has a compression ratio of 9.0:1 and uses Bosch Motronic 1.3 digital fuel injection. It was also offered without a catalytic converter for certain markets; this version produces and at the same engine speeds.^[46]

Applications:

• 1988-1989 E24 635CSi
• 1986-1992 E32 735i^{[46] [47]}
• 1987-1992 E34 535i
• 1988-1989 Rayton Fissore Magnum 3.5^[48]

Turbocharging

The M30 was the basis for the turbocharged M102 and M106 engines.

The Alpina B10 Biturbo used a modified version of the M30, with two turbochargers and forged pistons. Producing at 6000 rpm and at 4000 rpm, the engine made this car the fastest sedan in the world. The final 50 M30 blocks were shipped to Alpina for use in the final 50 B10 Biturbos.^[49]

M102

The M102 was produced from 1980 to 1982. It was BMW's first turbocharged six-cylinder engine.

The M102 (also known as M30B32LAE)^[50] has a displacement of 32101NaN1.^[51] The KKK K27 turbocharger produces 9psi of boost and an air-to-air intercooler is used.^[52] The compression ratio is 7.0:1.^[53]

The M102 produces and was used in the E23 7 Series, in the model was designated "745i".^[54] The M102 was not available in right-hand drive cars, leading to the South African 745i using the BMW M88 naturally aspirated DOHC straight-six engine instead.

Applications:

• 1980–1982 E23 745i

M106

The M106 (also called M30B34MAE) replaced the M102 and was produced from 1982 to 1986.

Some of the M106's upgrades over its predecessor are a result of the M30B34 version of the M30, which was also released in 1982. These upgrades include Bosch Motronic engine management and an increased displacement to 34301NaN1. The compression ratio was increased from 7.0:1 to 8.0:1.^[52]

Peak power output is the same as the M102,^[55] however it occurs at lower RPM^[56] and peak boost is reduced from 9to.^[57]

There was no direct successor to the M106, however BMW's next turbocharged petrol engine was the BMW N54, introduced in 2006.

Applications:

• 1982–1986 E23 745i

Motorsport

The M30 powered a series of E9 CSL and E24 6 Series coupes to European Touring Car Championship (ETCC) throughout the 1970s and into the middle 1980s, even though a more powerful DOHC 24-valve head had been developed for high-performance motorsports and street use.

The BMW M88 high-performance engine is based on the M30 block.^[58]

See also

• BMW
• BMW M10, the four-cylinder engine that the M30 was based on.
• BMW M20, the smaller straight-six engine which was sold alongside the M30 for many years.
• BMW M88, the high-performance, DOHC, straight-six engine that was sold alongside the M30 from 1978-1989
• BMW S38, the catalyzed version of— and ultimately the successor to— the M88, which was sold alongside the M30 from 1986-1995.
• List of BMW engines

Notes and References

1. Web site: Bmw Engine and Powerplant Identification Codes. www.rtsauto.com. 8 July 2010 . 8 September 2017.
2. Web site: Ward's 10 Best Engines include 2 BMW sixes. www.pacemotors.com.au. https://web.archive.org/web/20070522185127/http://www.pacemotors.com.au/ArticleView.asp?ArticleID=4. 22 May 2007.
3. Web site: BMW M68 car engine 2.5 litre . www.bmw-grouparchiv.de . 4 April 2021.
4. Web site: Bow Down To The E28 M5; Performance Cars Would Be Nothing Without It . www.carthrottle.com . 18 May 2015 . 1 December 2018 . en.
5. Web site: The Beginning of a Legacy – A BMW Motor Evolution . www.drive4corners.com . 5 November 2014 . 1 December 2018.
6. Book: Cranswick, Marc . The BMW 5 series and X5: a history of production cars and tuner specials, 1972-2008 . 2010 . McFarland . Jefferson, NC . 978-0786443512.
7. Web site: BMW Classic - BMW 525 (E12) . www.bmw-grouparchiv.de . 14 March 2021.
8. Web site: Easter Special: History of BMW motorsport, inc the factory 959BHP M30. www.bimmernut.com. https://web.archive.org/web/20121126092045/http://www.bimmernut.com/forum/5-series-bmw/20836-easter-special-history-bmw-motorsport-inc-factory-959bhp-m30-2.html. 26 November 2012.
9. Web site: BMW 7 Series (E23) 1977 - 1986. www.autoevolution.com. 1 September 2017.
10. Web site: 1981 BMW E28 525i Technical Specifications. www.ultimatespecs.com. 1 September 2017.
11. Web site: 1981 bmw E23 725i Technical Specifications. www.ultimatespecs.com. 1 September 2017.
12. Web site: 1986 BMW 725i (model up to mid-year 1986 for Europe) specifications. www.automobile-catalog.com. 1 September 2017.
13. Web site: 1975 BMW 2.8 L E3 specifications & stats . www.carfolio.com . 29 December 2018.
14. Book: Oswald, Werner . Deutsche Autos 1945-1990, Band 4. 1. 2001 . Motorbuch Verlag . Stuttgart . 3-613-02131-5.
15. Web site: Detailed specs review of 1971 BMW 2800 CS offered up to April 1971 for Europe Australia . www.automobile-catalog.com . 14 March 2021.
16. Web site: Detailed specs review of 1971 BMW Bavaria offered since mid-year 1970 for North America U.S. . www.automobile-catalog.com . 14 March 2021.
17. Web site: 1971 BMW Bavaria . www.goodingco.com . 14 March 2021 . en.
18. Book: Betriebsanleitung 518, 520, 525, 528, 520i . 15 January 1975 . BMW . 29 December 2018.
19. Web site: 1974 BMW E12 5 Series 528 Technical Specifications. www.ultimatespecs.com. 1 September 2017.
20. Web site: 1974 BMW 528 (model since mid-year 1974 for Europe Australia) specifications. www.automobile-catalog.com. 1 September 2017.
21. Book: Fahrzeugprospekt 518 520 520i 525 528 . January 1977 . BMW . 29 December 2018.
22. Web site: 1977 BMW 728 E23 specifications & stats . www.carfolio.com . 29 December 2018.
23. Web site: 1977 BMW E12 5 Series 528i Technical Specs . www.ultimatespecs.com . 9 December 2018 . en.
24. Web site: 1981 BMW 528i E28. www.carfolio.com.
25. Web site: 1971 BMW 3.0 S (model since April 1971 for Europe Australia) specifications. www.automobile-catalog.com. 1 September 2017.
26. Web site: 1971 BMW E9 3.0 CS Technical Specifications. www.ultimatespecs.com. 1 September 2017.
27. Book: Flammang, James M. . SCimp . Standard Catalog of Imported Cars, 1946-1990 . Krause Publications, Inc. . Iola, WI . 176–177 . 1994 . 0-87341-158-7 .
28. Web site: 1976 BMW 630 CS E24. www.carfolio.com. 1 September 2017.
29. Web site: BMW 730, 1977 MY E23. www.carfolio.com. 1 September 2017.
30. Web site: The BMW Six Cylinder Guide. www.autospeed.com. 8 September 2017.
31. Book: Quattroruote: Tutte le Auto del Mondo 74/75 . Editoriale Domus S.p.A . 1974 . TAM75 . Italian . 84 . Milano .
32. Web site: 1974 BMW E12 5 Series 530i(USA) Specs. www.ultimatespecs.com. 1 September 2017.
33. Web site: 1976 BMW 530 MLE E12. www.carfolio.com. 1 September 2017.
34. Web site: 1976 BMW 630 CSi E24. www.carfolio.com. 1 September 2017.
35. Web site: BMW 730i 6-cyl. (E32) . bmw-grouparchiv.de . 14 August 2019.
36. Web site: 1992 7 Series User Manual . bmw-grouparchiv.de . 9 December 2018.
37. Web site: BMW M30 and M102 Six Cylinder Engines. www.unixnerd.demon.co.uk. 1 September 2017. 21 December 2016. https://web.archive.org/web/20161221232350/http://www.unixnerd.demon.co.uk/m30.html. dead.
38. Web site: 1977 BMW 3.3 Li (model up to mid-year 1977 for Europe) specifications. www.automobile-catalog.com. 1 September 2017.
39. Web site: BMW 733i, 1977 MY E23. www.carfolio.com. 1 September 2017.
40. Web site: 1984 BMW 533i (model since mid-year 1983 for North America U.S.) specifications. www.automobile-catalog.com. 1 September 2017.
41. Web site: 333i: South Africa's Answer To The E30 M3 . https://web.archive.org/web/20221222170657/https://www.speedhunters.com/2019/10/333i-south-africas-answer-e30-m3/ . 2022-12-22 . Stefan . Kotzé . 2019-10-02 . Speedhunters . Electronic Arts Inc. .
42. Book: World Cars 1975 . L'Editrice dell'Automobile LEA/Herald Books . Pelham, NY . WC75 . 109 . 1975 . 0-910714-07-X .
43. Web site: E3 3.3L model selection. www.realoem.com. 1 September 2017.
44. Web site: 1985 BMW E28 5 Series M535i Specs. www.ultimatespecs.com.
45. Web site: 1985 BMW E28 5 Series M535i Kat Specs. www.ultimatespecs.com.
46. Book: BMW 7' [E32] Pressevorstellung ]. BMW 7 (E32) Press Presentation . de . 8 September 1986. 56–57 . BMW AG . 30 December 2018.
47. Web site: BMW E32 7 Series 735i Technical Specs, Dimensions. www.ultimatespecs.com. en. 2018-12-29.
48. Book: AR89 . Automobil Revue 1989 . Büschi . Hans-Ulrich . Hallwag AG . Berne, Switzerland . de, fr . 498 . 84 . March 9, 1989 . 3-444-00482-6 .
49. Palevsky. Alexander. Blown Away. Bimmer Magazine. October 2007. 62.
50. Web site: BMW Engine Numbers . 2012-08-18 . dead . https://web.archive.org/web/20131115021836/http://www.bmwe23.nl/http/BMW%20Engine%20Numbers.htm . 2013-11-15 .
51. Web site: BMW Heaven Specification Database | Engine specifications for M30 engines. Bmwheaven.com. 14 November 2021.
52. Web site: The BMW Six Cylinder Guide. Autospeed.com.
53. Web site: BMW 745i E23 Turbo. Uniquecarsandparts.com.au. 16 September 2017.
54. Web site: 2004 Engine Epic - BMW Engines . 2008-05-01 . Michael Knowling . 2004-04-26 . AutoSpeed . Web Publications Pty Limited . https://web.archive.org/web/20080509012508/http://autospeed.com/cms/A_2107/article.html. 9 May 2008 . live.
55. Web site: BMW Heaven Specification Database | Engine specifications for M30 engines. Bmwheaven.com. 14 November 2021.
56. Web site: The M102/M106 in the BMW 745i Turbo. Paultan.org. 24 January 2008. 14 November 2021.
57. Web site: BMW 745i E23 Turbo. Uniquecarsandparts.com.au. 14 November 2021.
58. Web site: FAQ E23 745i SA (M88). www.bmwmregistry.com. 1 September 2017.