BMW M52


The BMW M52 is a straight-6 DOHC petrol engine which was produced from 1994–2000. 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 from 1996–1999.
In 1998, the "technical update" 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.

Design

In most markets, the M52 switched from the M50's cast iron engine block to a lightweight aluminium engine block. However, in the United States and Canada, some cars 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 on the intake camshaft. The redline remained at 6,500 rpm.

Technical Update versions

In 1998, the M52TU was released, adding variable valve timing to the exhaust camshaft. Other upgrades included electronic throttle control, a dual length intake manifold and revised cylinder liners.

Models

M52B20

A version was introduced in 1994. Bore is and stroke is. The compression ratio is 11.0:1.
Applications:
The "technical update" in 1998 included double VANOS, which improved low rpm torque.
Applications:
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:
The "technical update" in 1998 included double VANOS, which improved low rpm torque.
Applications:
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:
The "technical update" in 1998 included double VANOS, which improved low rpm torque.
Applications:
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. Countries with high sulfur fuel received an iron block version of the M52, 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 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, cylinder head and single VANOS. 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, 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: