BMW M52

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.

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]

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)

• BMW engines
• BMW M50
• BMW M54