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BMW M88 engine
Bmw m88.jpg
Manufacturer BMW
Production 1978–1989
Configuration DOHC straight-6
Predecessor None
Successor BMW S38

The BMW M88 is a straight-6 DOHC petrol engine which was produced from 1978-1989. It is based on the M49 motorsport engine, which was used in the BMW 3.0CSi.[1]

The M88 was produced alongside the M30 engine, as the higher performance engine. The S38 was the equivalent engine to the M88 for North America from 1986 to 1989. In 1989, the S38 replaced the M88 worldwide.

The M90 is a SOHC engine which is based on the M88/1.


BMW engineers used a 4 valves per cylinder head and a single-row timing chain.[2] Kugelfischer fuel injection[3] was used with individual throttle valves[4] and the distinctive six inlet pipes.

The displacement is 3,453 cc (3.5 L; 210.7 cu in), with a bore x stroke of 93.4 mm × 84 mm (3.68 in × 3.31 in).


Engine Power Torque Years
M88/1 204 kW (273 hp)
@ 6500 rpm
330 N⋅m (243 lb⋅ft)
@ 5000 rpm
M88/2 671 kW (900 hp)
M88/3 213 kW (286 hp)
@ 6500 rpm
340 N⋅m (251 lb⋅ft)
@ 4500 rpm
M90 160 kW (215 hp) @
5,200 rpm
304 N⋅m (224 lb⋅ft)
@ 4,000 rpm


M88/1 with some parts replaced with Plexiglas for display purposes

The M88/1 was the first iteration of the M88 and was fitted to the BMW M1. It produced 277 PS (273 bhp; 204 kW) @ 6500rpm and 330 N⋅m (243 lbf⋅ft) @ 5500rpm.[5] A dry sump is used.[6]


  • 1978-1981 M1


For Group 5 racing, the M88 engine was turbocharged and became known as the M88/2. This race engine produced up to 670 kW (900 hp).[5]


  • Group 5 racing cars


M88/3 iteration used in the E24 M635CSi and E28 M5.

The M88/1 engine was modified for use in the E24 M635CSi and E28 M5 and was known as the M88/3.[7] The Kugelfischer fuel injection was replaced with Bosch Motronic producing 286 PS (282 bhp; 210 kW) at 6,500 rpm and 340 N⋅m (251 lbf⋅ft) at 4,500 rpm of torque.[8] It has a compression ratio of 10.5:1.

The M88/3 was also fitted to the South African BMW 745i, due to packaging problems with the turbocharged M102 engine which was used in other markets.[9]


  • 1983-1989 E24 M635CSi
  • 1985-1988 E28 M5
  • 1984-1986 E23 745i


The M90 engine is a lower performance SOHC engine that was based on the M88/1. It utilizes the same block from the M88 and maintains the same bore and stroke, but borrows its head from the BMW M30 engine family. Different years of M90 engines used both Bosch Motronic and Bosch L-Jetronic engine management systems.[3] Typically identified by a white L painted on the block behind the oil filter housing and coolant water passages on the side of the block.

The M90 sold in Europe and most other markets (except North America) used a compression ratio of 9.3:1, did not have a catalytic converter and produced 160 kilowatts (210 hp).


See also[edit]