The BMW M52 is a straight-6 DOHC petrol engine which was produced from 1994 to 2000. It was released in the E36 320i, to replace the M50. The BMW S52 engine is a high performance variant of the M52 which powered the American and Canadian market

E36 M3 The BMW M3 is a high-performance version of the BMW 3 Series, developed by BMW's in-house motorsport division, BMW M GmbH. M3 models have been produced for every generation of 3 Series since the E30 M3 was introduced in 1986. The initial mode ...

from 1996 to 1999. In 1998, the "technical update" (M52TU) upgrades included adding variable valve timing to the exhaust camshaft. The M52 was replaced by the M54 in the year 2000. The M52 and S52 engines were on the

Ward's 10 Best Engines 10 of the World's best engines is an annual list of the ten ''"''best''"'' automobile engines available in the U.S. market, that are selected by '' Ward's AutoWorld'' magazine. The list was started in 1994 for Model Year 1995, and has been drawn ev ...

list from 1997 to 2000.

Design

In most markets, the M52 switched from the M50's cast iron

engine block In an internal combustion engine, the engine block is the structure which contains the cylinders and other components. In an early automotive engine, the engine block consisted of just the cylinder block, to which a separate crankcase was attac ...

to a lightweight aluminium engine block. However, most M52 engines produced for the United States and Canadian markets (except for those used by the

BMW Z3 The BMW Z3 is a range of two-seater sports cars which was produced from 1995 to 2002. The body styles of the range are: * 2-door roadster (E36/7 model code) * 2-door coupé (E36/8 model code) The Z3 was based on the E36 3 Series platform, whi ...

roadster) retained the M50's cast iron engine block, while other cars used the new aluminum M52 block with iron sleeves. The largest version of the M52 is 2.8 litres, compared with 2.5 litres for the M50. As per the later versions of the M50, the M52 uses

variable valve timing In internal combustion engines, variable valve timing (VVT) is the process of altering the timing of a valve lift event, and is often used to improve performance, fuel economy or emissions. It is increasingly being used in combination with var ...

on the intake camshaft (called " single-VANOS"). The redline remained at 6,500 rpm.

Technical Update versions

In 1998, the ''M52TU'' ("Technical Update") was released, adding variable valve timing to the exhaust camshaft (called " double VANOS"). Other upgrades included a new design throttle body with the ASC (traction control) motor built in and throttle cable override, revised coolant passages with an additional drain back passage and a new cooling system with push fit hoses and a separate expansion tank plus a dual length intake manifold (called "DISA") and steel cylinder liners carried over from the previous M52, these replacing Nikasil in March 1998.

Models

M52B20

A version was introduced in 1994. Bore is and stroke is . The compression ratio is 11.0:1. Applications: * 1994-1998 E36 320i * 1995-1998 E39 520i

M52TUB20

The "technical update" in 1998 included double VANOS, which improved low rpm torque. Applications: * 1998-2000 E46 320i, 320Ci, * 1998-2000 E39 520i * 1999-2000 E36/7 Z3 2.0i

M52TUB24

2.4 L. For Thai market only. The bore is and the stroke is .

M52B25

A version introduced in 1995. It produces . Bore is and stroke . The compression ratio is 10.5:1. Applications: * 1995-1998 E36 323i * 1995-2000 E36/5 323ti * 1995-1998 E39 523i

M52TUB25

The "technical update" in 1998 included double VANOS, which improved low

rpm Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...

torque. Applications: * 1998-2000 E46 323i, 323Ci * 1998-2000 E39 523i * 1998-2000 E36/7 Z3 2.3i

M52B28

The version of the M52 debuted in 1995. It has a bore of , a stroke of and produces . The compression ratio is 10.2:1. Applications: * 1995-1999 E36 328i, 328is * 1995-1998 E39 528i * 1995-1998 E38 728i, 728iL * 1997-1998 E36/7 Z3 2.8 * 1997-2000

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(South Africa only)

M52TUB28

The "technical update" in 1998 included double VANOS, which improved low

torque. Applications: * 1998-2000 E46 328i, 328Ci * 1998-2000 E36/7/8 Z3 2.8 * 1998-2000 E39 528i * 1998-2000 E38 728i

Nikasil problems with high sulfur fuels

The aluminum M52 engine received criticism in some markets with high levels of sulfur in the petrol during the late 1990s. Sulfur has a corrosive effect on

Nikasil Nikasil is a trademarked electrodeposited lipophilic nickel matrix silicon carbide coating for engine components, mainly piston engine cylinder liners. Development Nikasil was introduced by Mahle in 1967, and initially developed to allow Wanke ...

and led to many early M52 and M60 engines having premature bore-liner wear. Countries with high sulfur fuel (such as the United States) received an iron block version of the M52 (except for the M52B28 in the Z3 which was an aluminium block), so the Nikasil problem does not apply to most M52 engines in these countries. Once the Nikasil coating was determined to be the cause of the problem, steel cylinder liners were used instead of the Nikasil coating. Therefore, the M52TU engine was not affected by the Nikasil problem.

S52

The S52 is a higher performance version of the M52, which replaced the S50B30US in the post-facelift (1996-1999) North American E36 M3. Compared to the European-spec S50, the S52 is less powerful. The S52 also shares more in common with the regular M52 engine than the S50 did with the M50, for example sharing the engine block (cast iron, as per North American M52 engines) and cylinder head. Unique to the S52 is a bore of and stroke of for a total displacement of 3,152 cc. Compression ratio is 10.5:1. Other upgrades over the M52 include lighter camshafts (with increased lift and duration), valve springs and the exhaust system. The S52 produces at 6,000 rpm and of torque at 3,800 rpm. The S52 has a redline of 7,000 rpm while the M52 has a 6,500 rpm redline. Applications: * 1996-1999 E36 M3 (Canada and United States only) * 1998-2000 E36/7/8 Z3M (Canada and United States only)

References

{{DEFAULTSORT:Bmw M52 M52 Straight-six engines Gasoline engines by model