BMW M52 engine
M52B28 in a E36 328i
Overview
Production	1994–2000
Layout
Configuration	Straight-6
Displacement	2.0–2.8 L (122–171 cu in)
Cylinder bore	80–84 mm (3.1–3.3 in)
Piston stroke	66–84 mm (2.6–3.3 in)
Cylinder block material	Aluminium / cast iron
Cylinder head material	Aluminium
Valvetrain	DOHC, with VVT
Valvetrain drive system	Chain
Combustion
Fuel type	Gasoline
Chronology
Predecessor	BMW M50
Successor	BMW M54

The BMW M52 is a straight-6 DOHC petrol engine which was produced from 1994 to 2000. It was released in the E36 320i,^[1] 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 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 list from 1997 to 2000.^[2]

Design

In most markets, the M52 switched from the M50's cast iron engine block 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 roadster) retained the M50's cast iron engine block,^[3][4] while other cars used the new aluminum M52 block with iron sleeves.^[3]

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

Models

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 and led to many early M52 and M60 engines having premature bore-liner wear.^[10][11][12] 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.^[13]

Once the Nikasil coating was determined to be the cause of the problem, steel cylinder liners were used instead of the Nikasil coating.^[14] Therefore, the M52TU engine was not affected by the Nikasil problem.^[15]

S52

BMW S52 engine
An S52B32 in an e36/7 M Roadster
Overview
Production	1996–2000
Layout
Configuration	straight-6
Displacement	3,152 cc (192 cu in)
Cylinder bore	86.4 mm (3.40 in)
Piston stroke	89.6 mm (3.53 in)
Cylinder block material	Cast iron
Cylinder head material	Aluminium
Valvetrain	DOHC, with VVT
Combustion
Fuel type	Gasoline
Chronology
Predecessor	BMW S50B30US
Successor	BMW S54

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 86.4 mm (3.4 in) and stroke of 89.6 mm (3.5 in) 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.^[16][17]

The S52 produces 240 hp (179 kW) at 6,000 rpm and 236 lb⋅ft (320 N⋅m) of torque at 3,800 rpm.^[18] 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)

See also

• BMW engines
• BMW M50
• BMW M54

References