BMW M20
BMW | |
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M20 in a BMW E30 |
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M20 | |
Production period: | 1976-1992 |
Manufacturer: | BMW |
Working principle: | Otto |
Motor design: | R6 |
Valve control: | SOHC |
Displacement: | 1990 cm 3 2316 cm 3 2494 cm 3 2693 cm 3 |
Mixture preparation: |
Carburettor or manifold injection |
Engine charging: | no |
Power: | 88-126 kW |
Dimensions: | approx. 170 kg |
Previous model: | none |
Successor: | BMW M50 |
The BMW M20 is a passenger car gasoline engine from the Bavarian engine manufacturer BMW , which was manufactured from 1976 to 1990 in Munich and from 1982 to 1992 in Steyr . The M20 is designed as a six-cylinder in - line engine with a displacement of 2 to 2.7 liters . The M21 diesel engine is considered to be the "descendant" of the M20 engine . The M20 was originally referred to as the M60 , but the changeover to the new naming scheme at BMW and thus the change to the M20 took place in 1983.
Development and production
The BMW M20 was developed as a “small” six-cylinder in the mid-1970s, as the “large” six-cylinder BMW M30 , built from 1968 onwards, was not suitable for the BMW E21 due to its dimensions . The cylinder spacing of the M30 was 100 mm, for the M20 a cylinder spacing of 91 mm was chosen, which resulted in a reduction in the external dimensions. The basic features were designed by Alexander von Falkenhausen , and the engine was ready for series production under Dr.-Ing. Karlheinz Lange brought. Originally designed as a 2.3-liter engine, a 2-liter version followed on the German market, and a 2.7-liter version, the eta version, was available on the North American market from 1981. Since the performance of the eta engine fell short of customer expectations, BMW developed a more powerful 2.5-liter engine as the last unit in the M20 family. The eta engine was also offered on the German market from 1983. The 2-liter M20 was offered throttled with 88 kW especially for the Austrian market.
The BMW M20 was produced by BMW engine construction in Munich from 1976 and at the same time at the BMW engine plant in Steyr from 1982 . By April 1990, 1.7 million cylinder heads had been manufactured for the unit in Munich, whereby the production of the M20 engines in Munich was discontinued in favor of the successor, the BMW M50 . The M20 continued to be built in small numbers at the Steyr plant. The M20 cylinder head line ended in Steyr on November 27, 1992; the last M21 cylinder head was manufactured on February 14, 1992. The last engine in engine assembly M20 / 21 rolled off the production line on December 17, 1992 in Steyr. At that time, the BMW M20 had largely been replaced by the BMW M50 six-cylinder engine, which had been in production since 1990 and which was equipped with four-valve technology .
use
The BMW M20 was used for the first time under the designation M60 (according to the old version number system) from 1977 in the 320 (E21) and 520 (E12) . In the BMW 3 and 5 series models, the M20 replaced the four-cylinder M10 engines with a displacement of two liters, which had been built in their basic design since 1961 , whereby the M10 engines with smaller displacements remained in the range until 1988.
The M20 was used in the E30 sedan until 1991 and in the E30 convertible and touring until 1993. The E30 successor E36 received the M50 engines with 2.0 and 2.5 l displacement in the 320i and 325i models from the start of production in 11/1990.
From May 1990 the M20 in the BMW E34 (520i / 525i) was replaced by the M50 engine with hydraulic valve lifters and chain drive of the camshaft, the main innovation of which was the four-valve technology and the associated increase in performance.
technical description
The M20 is a vertical and slightly inclined in-line six-cylinder engine with an overhead camshaft , which is water-cooled and works according to the Otto process . It has a slightly short stroke , the bore is 80 mm, the stroke 76.8 mm or 66 mm. Later there was also an 84 mm bore with a 75 mm or 81 mm stroke. This results in the four displacement variants 2.0 l, 2.3 l, 2.5 l and 2.7 l with outputs from 88 kW (120 PS) to 126 kW (171 PS).
The engine block is made of gray cast iron. All engines have a cylinder spacing of 91 mm. The M20 is the first BMW engine with a cast crankshaft.
The cylinder head made of an aluminum alloy is one-piece and designed as a cross-flow cylinder head . For the first time at BMW, the overhead camshaft was driven with a toothed belt instead of a timing chain . The camshaft actuates two V-shaped hanging valves per cylinder via rocker arms .
For mixture preparation, depending on the time of construction, size and series, a double register carburetor Solex 4A1 (320/6 or 520/6) and later a mechanical ( K-Jetronic ) or an electronic ( L-Jetronic / Motronic ) intake manifold injection in the 320i models was used / 323i / 325i / 520i / 525i. Alpina , Schnitzer and Hartge offered the engine with a higher output of up to 154.5 kW (210 hp), with the M20 versions installed in the Alpina C2 and B3 having a displacement of 2.7 liters. Characteristic of the BMW M20 with manifold injection is the cast intake manifold and thus realized resonance charging , in which the natural oscillation of the air column operates in a narrow speed range as a slight charge. This intake manifold differs only minimally in the respective displacement variants. Larger changes were made to the eta versions (2.7 l), although they were not immediately visible.
Special features of the eta version
Compared to the conventional M20 engine, the eta engine has longer intake manifolds, modified valve timing and reduced friction values thanks to measures such as softer valve springs, reduced piston ring preload and only four camshaft bearings. Due to the large displacement of 2.7 liters, the eta version has a significantly higher torque at low speeds. The maximum value of 178 Nm of the 2.0-l engine is achieved by the 2.7-l engine already below 1000 rpm, the maximum value is 240 Nm at 3250 rpm and thus roughly the same as that of the 528i or 528i . 728i offered "large" M30 six-cylinder with 2.8 liter displacement, which however achieves a significantly higher output (135 kW / 184 PS at 5400 rpm). Thanks to its Motronic control unit, which was technically highly developed in the 1980s, the eta engine achieves an exceptionally smooth engine run, good starting properties and low fuel consumption. However, since it does not correspond to the typical BMW character of high-speed engines, the market success of the eta models was limited, 305,982 units were produced. In 1986 the eta engine was revised. The rated power was increased to 95 kW by a modified cylinder head (from M20B25), the final speed was at 5300 min -1 raised.
Weak points
Engines built before 1989 have a cylinder head that is screwed to the engine block with hexagon bolts. The hex head bolts tend to break unexpectedly. Later models have Torx screws that are not affected by this problem.
Technical specifications
engine | Displacement | Bore × stroke | compression | Power at 1 / min | Torque at 1 / min | construction time |
---|---|---|---|---|---|---|
M20B20VE | 1990 cm 3 | 80.0 mm × 66.0 mm | 9.2: 1 | 90 kW (122 hp) at 6000 | 163 Nm (16.5 kpm) at 4000 | 1977-1982 |
M20B20 | 9.8: 1 | 92 kW (125 PS) at 5800 | 170 Nm (17.3 kpm) at 4000 | 1983-1985 | ||
9.8: 1 | 95 kW (129 hp) at 6000 | 174 Nm (17.7 kpm) at 4000 | 1985-1990 | |||
M20B20 cat | 8.8: 1 | 95 kW (129 hp) at 6000 | 164 Nm (16.7 kpm) at 4300 | 1986-1992 | ||
M20B23 | 2316 cm 3 | 80.0 mm × 76.8 mm | 9.8: 1 | 102 kW (139 PS) at 5300 | 205 Nm (20.9 kpm) at 4000 | 1983-09 / 1983 |
9.8: 1 | 110 kW (150 PS) at 6000 | 205 Nm (20.9 kpm) at 4000 | 09 / 1983-1985 | |||
9.5: 1 | 105 kW (143 hp) at 6000 | 176 Nm (17.9 kpm) at 4500 | 1978-1982 | |||
M20B25 | 2494 cm 3 | 84.0 mm × 75.0 mm | 9.7: 1 | 126 kW (171 hp) at 5800 | 226 Nm (23.0 kpm) at 4000 | 1985-1986 |
M20B25 cat | 8.8: 1 | 125 kW (170 hp) at 5800 | 222 Nm (22.6 kpm) at 4300 | 1986-1991 | ||
M20B27 | 2693 cm 3 | 84.0 mm × 81.0 mm | 11.0: 1 | 92 kW (125 PS) at 4250 | 240 Nm (24.5 kpm) at 3250 | 1982-1985 |
10.2: 1 | 95 kW (129 hp) at 4250 | 240 Nm (24.5 kpm) at 3250 | 1985-1986 | |||
9.0: 1 | 90 kW (122 PS) at 4250 | 230 Nm (23.5 kpm) at 3250 | 1985-1987 | |||
8.5: 1 | 95 kW (129 hp) at 4800 | 230 Nm (23.5 kpm) at 3200 | 1987-1988 |
At 170 to 175 kg, the mass of the engines was between that of the four-cylinder engines of the M10 type and that of the large six-cylinder engines of the BMW M30 type.
Usage overview
Engine code (old scheme) | Engine code | Start of production | End of production | Power (DIN-PS) | Power kW) | Mixture preparation | use |
---|---|---|---|---|---|---|---|
M60 / 2 | M20B20VE | 09/1977 | 1982 | 122 hp | 90 kW |
Double register carburetor Solex 4A1 |
E21 320 E12 520 |
M60 | M20B20KE | 09/1981 | 07/1985 | 125 hp | 92 kW | K-Jetronic |
E30 320i E28 520i |
M60 | M20B20LE | 09/1982 | 07/1985 | 125 hp | 92 kW | LE-Jetronic | E30 320i E28 520i |
M20B20LE | 09/1982 | 07/1985 | 125 hp | 92 kW | L-Jetronic | E30 320i E28 520i |
|
M20B20LE | ? | ? | 120 hp | 88 kW | L-Jetronic | E28 520i | |
M20B20 Cat | 09/1986 | 1991 | 129 hp | 95 kW | Bosch Motronic DME1.1
Bosch Motronic DME1.3 |
E30 320i E28 520i E34 520i |
|
M60 / 5 | M20B23LE | 1983 | 1985 | 139 hp | 102 kW | Bosch L-Jetronic | E30 323i |
M60 / 5 | M20B23KE | 02/1978 | 1982 | 143 hp | 105 kW | K-Jetronic | E21 323i |
M20B23LE | 1983 | 1985 | 150 hp | 110 kW | Bosch L-Jetronic | E30 323i | |
M20B25 | 1985 | 1986 | 171 hp | 126 kW | Bosch ME Motronic | E30 325i / iX | |
M20B25 Cat | 1986 | 1992 | 170 hp | 125 kW | Bosch DME 1.3 | E30 325i / iX Z1 E34 525i |
|
M20B27ME | 1983 | 1985 | 125 hp | 92 kW | Bosch DME ML1 | E28 525e | |
M20B27ME.E | 1985 | 1986 | 129 | 95 kW | Bosch DME ML | E28 525e | |
M20B27 Cat | 1985 | 1987 | 122 hp | 90 kW | Bosch DME ML | E30 325e E28 525e |
|
M20B27 Cat | 1986 | 1988 | 129 hp | 95 kW | Bosch DME1.1 | E30 325e E28 525e |
literature
- Dieter Korp : Now I'm helping myself (Volume 126): BMW 320i, 323i, 325i, 325e from December '82 ISBN 3-613-01183-2 .
- Hans-Rüdiger Etzold : This is how it's done (Volume 58): BMW 3 Series, Type E30, Sedan from 9/82 to 8/90, Touring from 9/87 to 9/94 ISBN 3-7688-0561-1 .
- Hans-Rüdiger Etzold: This is how it's done (Volume 68): BMW 5 Series 9/72 to 7/81 (TYPE E12), BMW 5 Series 7/81 to 8/87 (TYPE E28) , Delius Klasing, Bielefeld, 1990, ISBN 978-3-7688-0666-4
- Robert Bowen: BMW 3-Series (E30) Performance Guide 1982–1994 , CarTech, 2013, ISBN 978-1-934709-86-3
- Hans J. Schneider: BMW 5 Series - technology + types, models up to 1997, ISBN 978-3-7688-5789-5
Individual evidence
- ↑ a b c Etzold: This is how it's done (Volume 68) , p. 14
- ↑ BMW AG (Ed.): BMW M20B20 automobile engine (125 hp) . Retrieved February 19, 2018
- ↑ a b Schneider: BMW 5 Series - Technology + Types, Models up to 1997, ISBN 978-3-7688-5789-5 , p. 44.
- ↑ a b c BMW (Ed.): BMW M20B27 automobile engine (122 hp) , accessed on February 19, 2018
- ^ Bowen: BMW 3-Series (E30) Performance Guide 1982–1994 , p. 9
- ↑ a b c d BMW AG (Ed.): Operating Instructions, Service Booklet 518, 520i, 525e, 525i, 528i, 535i, M535i, 524td . August 1985, p. 150 (6-06) ( bmw-grouparchiv.de [accessed on October 10, 2017] archive signature AB-82-10).
- ↑ BMW AG (Ed.): Start of series production M20, 1st engine, Steyr. BMW AG, May 17, 1982, accessed on August 12, 2016 (archive number: UF-4064-1).
- ↑ 14 years of M20: An era is coming to an end . In: BMW AG (Ed.): Bayernmotor . BMW employee newspaper. No. 4 , April 2, 1990, ZDB -ID 558618-5 , p. 7 ( bmw-grouparchiv.de [accessed on August 11, 2016]).
- ↑ BMW AG (Ed.): Last cylinder head for M20 in the Steyr plant. BMW AG, November 27, 1992, accessed on August 12, 2016 (archive number: FF-3448-1).
- ^ BMW AG (ed.): The last M21 ZK is being built, Steyr. BMW AG, February 14, 1992, accessed on August 12, 2016 (archive number: UJ-1406-1).
- ↑ BMW AG (Ed.): Last engine M21 in engine assembly M 20/21. BMW AG, December 17, 1992, accessed on August 12, 2016 (archive number: FF-3450-1).
- ↑ BMW AG (ed.): BMW 323i (E21) . Retrieved February 19, 2018
- ↑ a b Etzold: So it's done (Volume 68) , p. 13
- ↑ BMW AG (ed.): BMW 325i (E30) . Retrieved February 19, 2018
- ↑ a b Karlheinz Lange: History of the engine - engine of history (BMW dimensions 1 + 2) . Ed .: BMW Mobile Tradition. 1st edition. tape 2 (1945-2000) , 1999, ISBN 3-932169-04-2 , Chapter 12: In-line engines from 1971, p. 256 .
- ↑ Bowen: BMW 3-Series (E30) Performance Guide 1982–1994 , p. 8
- ^ Schneider: BMW 5 Series - Technology + Types, Models up to 1997, ISBN 978-3-7688-5789-5 , pp. 100-101 and 202.
- ^ Bowen: BMW 3-Series (E30) Performance Guide 1982–1994 , p. 10
- ↑ Bowen: BMW 3-Series (E30) Performance Guide 1982–1994 , p. 24
Timeline of BMW gasoline engines for passenger cars since 1961 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Number of cylinders | Conception | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | |||||||||||||||||||||||||||||||||||||||||||||||||||||
0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | ||
3 | 1.5 l | B38 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
4th | (1.5–2.0 l) | M10 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
M40 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
M42 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
M43 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
M44 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N40 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N42 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N45 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N46 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N43 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N13 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N20 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
B48 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
High performance motor | S14 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
6th | Small six-cylinder (2.0-3.0 l) | M20 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
M50 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
M52 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
M54 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Large six-cylinder (2.5-3.5 l) | M30 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N52 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N53 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N54 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N55 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
B58 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
High performance motor | M88 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
S38 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
S50 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
S52 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
S54 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
S55 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
8th | 3.0-4.4 l | M60 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
M62 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N62 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N63 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
High performance motor | S62 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
S63 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
S65 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
10 | High performance motor | S85 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
12 | 5.0-6.6 l | M70 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
M73 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N73 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
N74 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
High performance motor | S70 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Number of cylinders | Conception | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th | 9 | 0 | 1 | 2 | 3 | 4th | 5 | 6th | 7th | 8th |
1960s | 1970s | 1980s | 1990s | 2000s | 2010s |