Type BMW SOHC Straight-4 Petrol Engine

The BMW M10 is a straight-4 SOHC piston engine produced from 1962 to 1988 with displacements ranging from 1499 cc to 1990 cc. It was first released in the New Class sedans and began to be phased out following the introduction of the M40 engine by 1987.

For mixture preparation of the original 1.5-liter engine with 75 or 80 hp was a single downdraft carburetor . This basic concept was followed by variants with 1.6, 1.8 and 2 liters displacement. With a carburetor, the two-liter engines were on PS 100, with two flat current - twin carburettors equipped models rendered 105-120 hp. The models 2000/2002 tii / 520i with mechanical blowfish injection came to 130 hp. The 1973 presented turbo 2002 reached with exhaust gas turbocharger even 170 hp.

1981 followed for the BMW E28 and a 1766 cc version of the engine with K-Jetronic intake manifold injection. 

End of the 1980s was in the BMW M3 (model E30), the BMW S14 four-valve only on 2.3, then 2.5 liters and already in the production version over 200 hp expanded. The S14 is based on the design on a slightly modified M10 engine block and a shortened cylinder head of the six-cylinder BMW M88 * (which was also used in the BMW M1 ). He had like this single throttle, but an electronic instead of a mechanical injection.

The engine was a commercial success with over 3.5 million produced in almost three decades across many BMW models It has a forged crankshaft, counter balance weights, five main bearings and a chain-driven camshaft. The block is made from cast iron and the head is made from aluminium.

It was also used as the basis for the turbocharged BMW M12 motorsport engine, which for instance was used by Brabham-BMW in the Formula One racing series.

While BMW let it with the series engines until the 1970s with 2 valves per cylinder, came in the course of the European Touring Car Championship Kugelfischer injections with individual throttle or flat valves and four-valve cylinder heads are used. In Formula 2 (where the engines based on the M10 were extremely successful) and the German Racing Championship were already 300 hp possible. During this time, Schnitzer Motorsport also developed a four-valve cylinder head for the BMW M10, all other four-valve engines came from the factory. This was designed primarily for use in touring cars and rally cars of the type BMW 02 .

The engine was designed by engineer and race driver Baron Alex von Falkenhausen. In the late 1950s, he was asked to design a small-displacement (1.3 L) engine, but felt that this would be insufficient for the company's future needs. Therefore, he convinced BMW that the capacity should be 1.5 L instead and he designed a block that could be expanded to 2.0 L in the future. BMW M10 Engine utilized Hemispherical combustion chamber in 8 valve arrangement.

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 and the "18" represents the 1.8 litre capacity).

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

BMW 1500 engine

M115

The 1.5 L (1499 cc/91 in³) M115 produced 75 hp or 80 hp (56 kW or 60 kW), depending on the state of tune. Bore is 82 mm (3.2 in), stroke is 71 mm (2.8 in). Lower power models use an 8:1 compression ratio, while higher power models use a ratio of 8.8:1. Fuel is supplied via a Solex 38 PDSI carburettor.

Applications:

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

M10 B16 

M116

The 1.6 L (1573 cc/95 in³) M116 used a Solex 38 PDSI carburettor and produced 63 kW (84 hp). Bore is 84 mm (3.3 in), stroke is 71 mm (2.8 in) and compression ratio is 8.6:1.

Applications:

• 1964-1966 BMW 1600
• 1966-1975 BMW 1600-2/1602

A version using twin Solex 40 PHH carburettors and a compression ratio of 9.5:1 produced 78 kW (105 hp)

Applications:

• 1967-1968 BMW 1600 ti

M41

The 1.6 L (1573 cc/95 in³) M41 produced 67 kW (90 hp) and 123 N·m (91 lb·ft). It has a 8.3:1 compression ratio and fuel is supplied by a Solex 32 DIDTA carburettor.

Applications:

• 1975 E21 316

M98

The 1.6 L (1573 cc/95 in³) M98 produces 55 kilowatts (74 hp). Fuel is supplied by a Pierburg 1B2 carburettor and the compression ratio is 9.5:1.

Applications:

• 1981-1983 E21 315

BMW 1800ti Engine

M118

The 1.8 L (1773 cc/108 in³) M118 produces 66–95 kW (89–127 hp), depending on specification, with bore is 84 mm (3.3 in) and stroke is 80 mm (3.1 in).

Applications:

• 1963-1968 1800: 67 kW (90 hp), 8.6:1 compression, Solex 36-40 PDSI carburettor
• 1974 E12 518: 67 kW (90 hp), 8.6:1 compression, Solex 38 PDSI carburettor
• 1963-1966 1800ti: 81 kW (109 hp), 9.5:1 compression, 2x Solex 40 PHH carburettors
• 1965 1800tiSA: 95 kW (127 hp), 10.5:1 compression, 2x Weber DCOE-45 carburettors

M10B18

The 1.8 L (1766 cc/107 in³) M10B18 produces 74–77 kW (99–103 hp), depending on specification. Bore is 89 mm (3.5 in), stroke is 71 mm (2.8 in).

Applications:

• 1969-1972 1800: 67 kW (90 hp), 8.6:1 compression, Solex 36-40 PDSI carburettor
• 1971-1975 BMW 1802: 67 kW (90 hp), 8.6:1 compression, Solex 38 PDSI carburettor
• 1980-1983 E21 320i/320is (USA): 74 kW (99 hp), 8.8:1 compression, Bosch K-Jetronic EFI
• 1980-1983 E12 518 (South Africa): 77 kW (103 hp), 10:1 compression, Bosch K-Jetronic EFI
• 1982-1987 E30 318i: 77 kW (103 hp), 10:1 compression, Bosch L-Jetronic EFI
• 1981-1988 E28 518i: 77 kW (103 hp), 9.5:1 compression, Bosch LE-Jetronic EFI

BMW 2000 tii Fuel injection Engine

M10B20

M05

The 2.0 L (1990 cc/121 in³) M05 has a bore of 89 mm and a stroke of 80 mm. It produces 75–89 kW (101–119 hp), depending on specification.

Applications:

• 1965-1970 BMW 2000CS: 89 kW (119 hp), 9.3:1 compression, 2x Solex 40 PHH carburettors
• 1966-1970 BMW 2000C: 75 kW (101 hp), 8.5:1 compression, Solex 40 PDSI carburettor
• 1966-1972 BMW 2000: 75 kW (101 hp), 8.5:1 compression, Solex 40 PDSI carburettor
• 1966-1971 BMW 2000ti: 89 kW (119 hp), 9.3:1 compression, 2x Solex 40 PHH carburettors
• 1968-1976 BMW 2002: 75 kW (101 hp), 8.5:1 compression, Solex 40 PDSI carburettor

M17

The 2.0 L (1990 cc/121 in³) M17 produces 85 kW (114 hp). It has a Stromberg 175 CDET carburettor and a compression ratio of 9.0:1.

Applications:

• 1972-1977 E12 520

M15

The 2.0 L (1990 cc/121 in³) M15 used the Kugelfischer mechanical fuel injection and produced 97 kW (130 hp). It was the famed tii engine.

Applications:

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

M43

The 2.0 L (1990 cc/121 in³) M43/1 has a compression ratio of 8.1:1 and produces 80 kW (107 hp).

Applications:

• 1975-1979 E21 320 (Solex 32-32 DIDTA carburettor)
• 1975-1979 E21 320i (USA only, Bosch K-Jetronic EFI)

M64

The 2.0 L (1990 cc/121 in³) M64 has a compression ratio of 9.3:1, uses K-Jetronic fuel injection and produces 93 kW (125 hp).

Applications:

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

M31

The 2.0 L (1990 cc, 121 in³) M31 used a KKK turbocharger and Kugelfischer P04 mechanical fuel injection with a sliding throttle plate. It has a compression ratio of 6.9:1 and produces 125 kW (168 hp).

Applications:

• 1973-1975 2002 turbo