# 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.
The M10 was used in many BMW models, with over 3.5 million being produced during its 26 year production run.
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.
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. 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. It features a forged crankshaft, counterbalance weights, five main bearings and a chain-driven camshaft.
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).

## 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 |
| M115 | 1,499 cc (91.5 cu in) | 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 |
| M116 | 1,573 cc (96.0 cu in) | 77 kW (105 PS; 103 hp) at 6000 rpm | 141 N⋅m (104 lb⋅ft) at 4500 rpm | 1967–1968 |
| M41 | 1,573 cc (96.0 cu in) | 66 kW (90 PS; 89 hp) at 6000 rpm | 167 N⋅m (123 lb⋅ft) at 4000 rpm | 1975-1980 |
| M98 | 1,573 cc (96.0 cu in) | 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 |
| M10B18 | 1,766 cc (107.8 cu in) | 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 |
| 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 |
| M118 | 1,773 cc (108.2 cu in) | 81 kW (110 PS; 108 hp) at 5800 rpm | 148 N⋅m (109 lb⋅ft) at 4000 rpm | 1964–1976 |
| M118 | 1,773 cc (108.2 cu in) | 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 |
| M05 | 1,990 cc (121.4 cu in) | 88 kW (120 PS; 118 hp) at 5600 rpm | 167 N⋅m (123 lb⋅ft) at 3500 rpm | 1965–1971 |
| M17 | 1,990 cc (121.4 cu in) | 85 kW (115 PS; 113 hp) at 5800 rpm | 165 N⋅m (122 lb⋅ft) at 3700 rpm | 1972-1977 |
| M15 | 1,990 cc (121.4 cu in) | 96 kW (130 PS; 128 hp) at 5800 rpm | 177 N⋅m (131 lb⋅ft) at 4500 rpm | 1970–1974 |
| M43 | 1,990 cc (121.4 cu in) | 80 kW (109 PS; 107 hp) at 5800 rpm | 160 N⋅m (118 lb⋅ft) at 3700 rpm | 1975-1983 |
| M64 | 1,990 cc (121.4 cu in) | 92 kW (125 PS; 123 hp) at 5700 rpm | 175 N⋅m (129 lb⋅ft) at 4350 rpm | 1975-1979 |
| M10B20 | 1,990 cc (121.4 cu in) | 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:
* 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:
* 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), depending on specification. The bore is 84 mm (3.3 in) and the stroke is 80 mm (3.1 in).
Applications:
* 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.
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.