BMW M88

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title: "BMW M88" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["bmw-engines", "world-sportscar-championship-engines", "straight-six-engines", "gasoline-engines-by-model"] topic_path: "sports" source: "https://en.wikipedia.org/wiki/BMW_M88" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::data[format=table title="Infobox automobile engine"]

Field	Value
image	Bmw m88.jpg
name	BMW M88 engine
aka	{{ubl
manufacturer	BMW
production	1978–1989
predecessor	None
successor	BMW S38
configuration	Straight-6
bore	93.4 mm
stroke	84 mm
displacement	3453 cc
valvetrain	DOHC (M88)
SOHC (M30B35LE/M90)
fueltype	Petrol
head	Aluminium
block	Cast iron
::

|image=Bmw m88.jpg |name=BMW M88 engine |aka = {{ubl | BMW M30B35LE | BMW M90 |manufacturer=BMW |production=1978–1989 |predecessor=None |successor=BMW S38 |configuration= Straight-6 |bore=93.4 mm |stroke=84 mm |displacement=3453 cc |valvetrain= DOHC (M88) SOHC (M30B35LE/M90) |fueltype=Petrol |head=Aluminium |block=Cast iron

The BMW M88 is a straight-6 DOHC petrol engine which was produced from 1978 to 1989. It is based on the DOHC version of the BMW M49 engine, which was used in the BMW 3.0CSi racing cars.

The M88 was produced alongside the BMW M30 engine, as the higher performance engine. In North America up until 1989, the BMW S38 engine was used instead of the M88. In 1989, an updated version of the S38 became the worldwide replacement for the M88. The M30B35LE is a SOHC engine which is based on the M88/1; this is sometimes referred to as the M90.

Design

BMW engineers used a DOHC valvetrain on a production engine for the first time on the M88, with the camshafts driven by a single-row timing chain. Kugelfischer fuel injection and the distinctive six individual throttle bodies.

The construction is an aluminium cylinder head and a cast iron block. The bore is 93.4 mm and the stroke is 84.0 mm, resulting in a displacement of 3453 cc.

Versions

::data[format=table]

Engine code	Power	Torque	Years	Note
M88	277 PS
at 6,500 rpm	330 Nm
at 5,000 rpm	1978-1981	BMW M1
M88/1	470 PS
at 9,000 rpm	390 Nm
at 7,000 rpm	1979-1980	Gr.4 Procar
M88/2	up to 850-1000 PS
at 9,000 rpm	847-1017 Nm at 7,000 rpm	1979-1981	Gr. 5 turbo
M88/3	286 PS
at 6,500 rpm	340 Nm
at 4,500 rpm	1983–1989	M635 CSi, M5, 745i (South Africa only)
M30B35LE/M90	218 PS
at 5,200 rpm	304 Nm
at 4,000 rpm	1978–1982	SOHC
::

M88

::figure[src="https://upload.wikimedia.org/wikipedia/commons/f/ff/BMW_M1_Ausstellungsmotor.jpg" caption="M88/1 with some parts replaced with Plexiglas for display purposes"] ::

The M88 was the original iteration of the engine and was fitted to the BMW M1. It produces 277 PS at 6,500 rpm and 330 Nm at 5,500 rpm. A dry sump is used.

Applications:

• 1978-1981 M1

M88/1

For the BMW M1 Procar single-make series, the M88 engine was bored out marginally to reach 3498 cc. This racing version, called the M88/1, met the Group 4 regulations. This race engine produced 350 kW in Procar specifications. This version had forged pistons, sharper camshafts, bigger valves, as well as oil cooling for the transmission and rear differential.

Applications:

• 1979-1980 Procar BMW M1

M88/2

For Group 5 racing, the M88 engine was turbocharged and became known as the M88/2. It was downsleeved and had a shorter stroke to displace 3191 cc, which with the 1.4 turbo factor placed it in the 4.5-liter class. This race engine produced up to 670 kW.

Applications:

• Group 5 racing cars (BMW M1 Group 5 page)

M88/3

::figure[src="https://upload.wikimedia.org/wikipedia/commons/6/63/BMW_M88_3_Auspuffseite.JPG" caption="E28 M5]]."] ::

The M88/1 engine was modified for use in the E24 M635CSi and E28 M5 and was known as the M88/3. The Kugelfischer fuel injection was replaced with Bosch Motronic producing 210 kW at 6,500 rpm and 340 Nm at 4,500 rpm. 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.

Applications:

• 1983-1989 E24 M635CSi
• 1984-1987 E28 M5
• 1984-1987 E23 745i (South Africa only)

{{anchor|M90|M30B35|SOHC}} M30B35LE

The M30B35LE is a lower performance, two-valve, SOHC version of the M88/1 engine, also known as the M90. It utilizes the same block as the M88 and maintains the same bore and stroke, but borrows its head from the BMW M30 engine family. Depending on year, this engine uses either Bosch Motronic or Bosch L-Jetronic as its engine management system. 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.

As sold in Europe and most other markets (except North America), this engine used a compression ratio of 9.3:1, did not have a catalytic converter, and produced 160 kW.

Applications:

• 1979-1981 E12 M535i
• 1978-1982 E24 635CSi
• 1978-1982 E23 735i

References

References

1. "The Story of 40 Years BMW M ‒ The BMW M1".
2. (11 May 2017). "Top 5 Great BMW Engines".
3. (20 March 2018). "M Division's Greatest Competition Engines – Infernal Combustion". Infernalco.co.
4. Horatiu Boeriu. (24 May 2012). "Chris Harris Drives the E28 BMW M5". Bmwblog.com.
5. (23 August 2009). "Engine FAQ". Bimmerforums.com.
6. (16 March 2016). "1984 BMW 745i E23 5-Speed manual M88 engined SA model road test".
7. (July 2025). "BMW M88 and S38 M-Tech 24 Valve Six Cylinder Engines".
8. "Issue #07".
9. "From M121 to P48: An overview of the evolution of BMW Turbo engines in motor racing".
10. "Spicer Horsepower and Torque Calculator".
11. "The BMW Six Cylinder Guide".
12. "Car Lust: BMW M1".
13. "BMW World - BMW M Parts Series".
14. "FAQ E24 M635CSi + M6". BMW M Registry.
15. "FAQ E23 745i SA (M88)". BMW M Registry.
16. "M1 Technology". Projectm1.com.

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