BMW M10

The BMW M10 is a SOHC inline-4 petrol engine which was produced by BMW from 1962-1988. It was the company's first four-cylinder engine since the BMW 309 ended production in 1936 and was introduced in the New Class sedans.

BMW M10 engine
Overview
Production	1962–1988
Layout
Configuration	Inline-4
Displacement	1.5 L (1,499 cc) 1.6 L (1,573 cc) 1.8 L (1,766 cc) 1.8 L (1,773 cc) 2.0 L (1,990 cc)
Cylinder bore	82 mm (3.23 in) 84 mm (3.31 in) 89 mm (3.5 in)
Piston stroke	71 mm (2.8 in) 80 mm (3.15 in)
Cylinder block material	Cast iron
Cylinder head material	Aluminium
Valvetrain	SOHC
Combustion
Fuel system	Solex carburetor Stromberg carburettor Kugelfischer mechanical FI Bosch Jetronic manifold injection
Fuel type	Petrol
Chronology
Predecessor	None
Successor	BMW M40

The M10 was used in many BMW models, with over 3.5 million being produced during its 26 year production run.^[1]

The turbocharged BMW M12 engine— used in the Formula One racing— was based on the M10 engine block and produced up to 1,400 PS (1,030 kW) in qualifying trim.^{[citation needed]}

Following the introduction of the BMW M40 engine in 1987, the M10 began to be phased out.

Development

Baron Alex von Falkenhausen — an engineer and racing driver — designed the M10 in the late 1950s.^[1] He was asked by BMW to design an engine with a displacement of 1.3 L (79 cu in), but felt that this would be insufficient for the company's future needs. He convinced management that the minimum capacity should be 1.5 L (92 cu in), and offered an engine that could be expanded to a maximum of 2.0 L (122 cu in).

Design

The M10 has a cast iron block and an aluminum alloy head with hemispherical combustion chambers and two valves per cylinder.^[2] It features a forged crankshaft, counterbalance weights, five main bearings and a chain-driven camshaft.^[3]

The initial version of the M10 had a bore of 82 mm (3.2 in) and a stroke of 71 mm (2.8 in), resulting in a displacement of 1,499 cc (91.5 cu in). The peak power rating was 59 kW (80 PS; 79 hp).^[4][5]

Naming conventions

The engine was initially known as the "M115" (the last two digits representing the 1.5–litre capacity). Over the years, variants of the engine were given various codes (most of them starting with "M1" and the remaining digits relating to the capacity). In 1975, the engine became known as then "M10", then in 1980 it was given the standardised BMW engine code of M10B18 (where "M10" represents the series, B represents petrol (Benzin in German) and the "18" represented its then 1.8–litre capacity).

The M115 and all related engines have become retroactively known as the "M10" family.

Versions

Version	Displacement	Power	Torque	Year
M115	1,499 cc (91.5 cu in)	55 kW (75 PS; 74 hp) at 5800 rpm	118 N⋅m (87 lb⋅ft) at 3700 rpm	1974–1977
		59 kW (80 PS; 79 hp) at 5700 rpm	118 N⋅m (87 lb⋅ft) at 3000 rpm	1962-1964
M116	1,573 cc (96.0 cu in)	63 kW (85 PS; 84 hp) at 5800 rpm	130 N⋅m (96 lb⋅ft) at 3500 rpm	1964–1975
		77 kW (105 PS; 103 hp) at 6000 rpm	141 N⋅m (104 lb⋅ft) at 4500 rpm	1967–1968
M41		66 kW (90 PS; 89 hp) at 6000 rpm	167 N⋅m (123 lb⋅ft) at 4000 rpm	1975-1980
M98		55 kW (75 PS; 74 hp) at 5800 rpm	110 N⋅m (81 lb⋅ft) at 3200 rpm	1981-1983
M10B18	1,766 cc (107.8 cu in)	74 kW (100 PS; 99 hp) at 5800 rpm	135 N⋅m (100 lb⋅ft) at 3500 rpm	1980-1983
		77 kW (105 PS; 103 hp) at 5800 rpm 75 kW (102 PS; 101 hp)	145 N⋅m (107 lb⋅ft) at 4500 rpm 135 N⋅m (100 lb⋅ft)	1980–1988 S/CH[6]
M118	1,773 cc (108.2 cu in)	66 kW (90 PS; 89 hp) at 5,250 rpm	144 N⋅m (106 lb⋅ft) at 3000 rpm	1963–1974
		81 kW (110 PS; 108 hp) at 5800 rpm	148 N⋅m (109 lb⋅ft) at 4000 rpm	1964–1976
		96 kW (130 PS; 128 hp) at 6100 rpm	157 N⋅m (116 lb⋅ft) at 5100 rpm	1964-1965
M05	1,990 cc (121.4 cu in)	74 kW (100 PS; 99 hp) at 5500 rpm	157 N⋅m (116 lb⋅ft) at 3000 rpm	1968–1976
		88 kW (120 PS; 118 hp) at 5600 rpm	167 N⋅m (123 lb⋅ft) at 3500 rpm	1965–1971
M17		85 kW (115 PS; 113 hp) at 5800 rpm	165 N⋅m (122 lb⋅ft) at 3700 rpm	1972-1977
M15		96 kW (130 PS; 128 hp) at 5800 rpm	177 N⋅m (131 lb⋅ft) at 4500 rpm	1970–1974
M43		80 kW (109 PS; 107 hp) at 5800 rpm	160 N⋅m (118 lb⋅ft) at 3700 rpm	1975-1983
M64		92 kW (125 PS; 123 hp) at 5700 rpm	175 N⋅m (129 lb⋅ft) at 4350 rpm	1975-1979
M10B20		81 kW (110 PS; 109 hp) at 5700 rpm	152 N⋅m (112 lb⋅ft) at 4350 rpm	1977-1979
M31	1,990 cc (121.4 cu in) turbo	125 kW (170 PS; 168 hp) at 5800 rpm	245 N⋅m (181 lb⋅ft) at 4000 rpm	1973-1975

1499 cc engines

The M115 version has a displacement of 1,499 cc (91.5 cu in) and produces 55–60 kW (75–82 PS; 74–80 hp). It has a bore of 82 mm (3.2 in) and a stroke of 71 mm (2.8 in). Lower power models have a compression ratio of 8.0:1, while higher power models have a compressions ratio of 8.8:1. Fuel is supplied via a Solex 38 PDSI carburettor.

Applications:^[7][8]

• 1962-1964 BMW 1500
• 1975-1977 BMW 1502

1573 cc engines

The M116 version has a displacement of 1,573 cc (96.0 cu in) and produces 63–77 kW (86–105 PS; 84–103 hp). It has a bore of 84 mm (3.3 in) and a stroke of 71 mm (2.8 in). The standard specification has a compression ratio of 8.6:1 and uses a Solex 38 PDSI carburettor. The 1600 ti version has a compression ratio of 9.5:1 and uses twin Solex 40 PHH carburettors.

Applications:

• 1964-1966 BMW 1600— 63 kW (86 PS)
• 1966-1975 BMW 1600-2/1602— 63 kW (86 PS)
• 1967-1968 BMW 1600 ti— 77 kW (105 PS)

The M41 version produces 66 kW (90 PS; 89 hp), has an 8.3:1 compression ratio and fuel is supplied by a Solex 32 DIDTA carburettor.

Applications:

• 1975-1980 E21 316

The M98 version produces 55 kW (75 PS; 74 hp), has a compression ratio of 9.5:1 and uses a Pierburg 1B2 carburettor.

Applications:^[9]

• 1981-1983 E21 315

1766 cc engines

The M10B18 version has a displacement of 1,766 cc (107.8 cu in) and produces 66–77 kW (90–105 PS; 89–104 hp), depending on specification. The bore is 89 mm (3.5 in) and the stroke is 71 mm (2.8 in).

Applications:

• 1969-1972 1800— 66 kW (90 PS), 8.6:1 compression, Solex 36-40 PDSI carburettor
• 1971-1975 1802— 66 kW (90 PS), 8.6:1 compression, Solex 38 PDSI carburettor
• 1980-1983 E21 320i/320is— U.S. only, 75 kW (101 hp), 8.8:1 compression, Bosch K-Jetronic mechanical fuel injection
• 1980-1983 E12 518— South Africa only, 77 kW (105 PS), 10.0:1 compression, Bosch K-Jetronic mechanical fuel injection
• 1982-1987 E30 316 — 66 kW (90 PS), 9.5:1 compression, Pierburg 2BE carburettor, Ecotronic.
• 1982-1988 E30 318i— 77 kW (105 PS), 10.0:1 compression, Bosch L-Jetronic electronic fuel injection
• 1981-1988 E28 518i— 77 kW (105 PS), 9.5:1 compression, Bosch LE-Jetronic mechanical fuel injection.

1773 cc engines

The M118 version has a displacement of 1,773 cc (108.2 cu in) and produces 66–96 kW (90–130 PS; 89–128 hp),^[10] depending on specification. The bore is 84 mm (3.3 in) and the stroke is 80 mm (3.1 in).

Applications:^[11]

• 1963-1968 1800— 66 kW (90 PS), 8.6:1 compression, Solex 36-40 PDSI carburettor
• 1963-1966 1800ti— 81 kW (110 PS), 9.5:1 compression, twin Solex 40 PHH carburettors
• 1964-1965 1800tiSA— 96 kW (130 PS), 10.5:1 compression, twin Weber DCOE-45 carburettors
• 1974-1981 E12 518— 66 kW (90 PS), 8.6:1 compression, Solex 38 PDSI carburettor

1990 cc engines

The M05 version has a displacement of 1,990 cc (121.4 cu in) and produces 74–88 kW (100–120 PS; 99–118 hp), depending on specification. It has a bore of 89 mm (3.5 in) and a stroke of 80 mm (3.1 in).

Applications:

• 1965-1970 BMW 2000CS— 88 kW (120 PS), 9.3:1 compression, 2x Solex 40 PHH carburettors
• 1966-1970 BMW 2000C— 74 kW (100 PS), 8.5:1 compression, Solex 40 PDSI carburettor
• 1966-1972 BMW 2000— 74 kW (100 PS), 8.5:1 compression, Solex 40 PDSI carburettor
• 1966-1971 BMW 2000ti— 88 kW (120 PS), 9.3:1 compression, 2x Solex 40 PHH carburettors
• 1968-1976 BMW 2002— 74 kW (100 PS), 8.5:1 compression, Solex 40 PDSI carburettor

The M15 version used the Kugelfischer mechanical fuel injection and produced 96 kW (130 PS; 128 hp). It was also known as the tii engine.

Applications:

• 1970-1973 2000tii
• 1972-1974 2002tii
• 1972-1974 E12 520i

The M17 version produces 85 kW (115 PS). It has compression ratio of 9.0:1 and uses either a Stromberg 175 CDET or a Solex 4A1 carburettor.^{[citation needed]}

Applications:

• 1972-1977 E12 520

The M43/1 version has a compression ratio of 8.1:1 and produces 81 kW (110 PS; 109 hp).

Applications:

• 1975-1979 E21 320— Solex 32-32 DIDTA carburettor
• 1975-1979 E21 320i— USA only, Bosch K-Jetronic mechanical fuel injection

The M64 version produces 92 kW (125 PS). It has a compression ratio of 9.3:1 and uses Bosch K-Jetronic mechanical fuel injection.

Applications:

• 1975-1978 E21 320i
• 1975-1979 E12 520i

The M31 version uses a KKK BLD turbocharger operating @ 7psi and produces 125 kW (170 PS). It has a compression ratio of 6.9:1 and uses Schafer PL 04 mechanical fuel injection.

Applications:

• 1973-1975 2002 turbo

Related engines

• The highly successful M12 turbocharged motorsport engine was based on the M10 engine block.

• The S14 engine used in the E30 M3 was based on the M10 block.^[12]

See also

• List of BMW engines