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,[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 1996–1999.
| BMW M52 engine | |
|---|---|
 | |
| Overview | |
| Production | 1994–2000 |
| Layout | |
| Configuration | straight-6 |
| Displacement | 2.0–2.8 L (122–171 cu in) |
| Block material | Aluminium / cast iron |
| Head material | Aluminium |
| Valvetrain | DOHC, with VVT |
| Combustion | |
| Fuel type | Gasoline |
| Chronology | |
| Predecessor | BMW M50 |
| Successor | BMW M54 |
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, in the United States and Canada, some cars (not including the Z3) 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.
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 electronic throttle control (which uses a throttle cable as backup),[5] a dual length intake manifold (called "DISA") and revised cylinder liners.[6]
Models
| Engine | Displacement | Power | Torque | Years |
|---|---|---|---|---|
| M52B20 | 1,991 cc (121 cu in) | 110 kW (148 bhp) at 5900 rpm | 190 N⋅m (140 lb⋅ft) at 4200 rpm | 1994-1998 |
| M52TUB20 | 110 kW (148 bhp) at 5900 rpm | 190 N⋅m (140 lb⋅ft) at 3500 rpm | 1998-2000 | |
| M52TUB24 | 2,394 cc (146 cu in) | 135 kW (181 bhp) at 5800 rpm | 240 N⋅m (180 lb⋅ft) at 3600 rpm | 1998-2000 |
| M52B25 | 2,494 cc (152 cu in) | 125 kW (168 bhp) at 5500 rpm | 245 N⋅m (181 lb⋅ft) at 3950 rpm | 1995-1998 |
| M52TUB25 | 125 kW (168 bhp) at 5500 rpm | 245 N⋅m (181 lb⋅ft) at 3500 rpm | 1998-2000 | |
| M52B28 | 2,793 cc (170 cu in) | 142 kW (190 bhp) at 5300 rpm | 280 N⋅m (210 lb⋅ft) at 3950 rpm | 1995-1998 |
| M52TUB28 | 142 kW (190 bhp) at 5500 rpm | 280 N⋅m (210 lb⋅ft) at 3500 rpm | 1998-2000 | |
| S52B32 | 3,152 cc (192 cu in) | 179 kW (240 bhp) at 6000 rpm | 325 N⋅m (240 lb⋅ft) at 3800 rpm | 1996-2000 |
M52B20
A 1,991 cc (121 cu in) version was introduced in 1994. Bore is 80 mm (3.1 in) and stroke is 66 mm (2.6 in).[7] 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 84 mm (3.3 in) and the stroke is 72 mm (2.8 in).
M52B25
A 2,494 cc (152 cu in) version introduced in 1995.[8] It produces 125 kW (168 hp). Bore is 84 mm (3.3 in) and stroke 75 mm (3.0 in). The compression ratio is 10.5:1.
Applications:
- 1995-1998 E36 323i,
- 1995-2000 E36/5 323ti
- 1995-2000 E39 523i
M52TUB25
The "technical update" in 1998 included double VANOS, which improved low rpm torque.
Applications:
- 1998-2000 E46 323i, 323Ci
- 1998-2000 E39 523i
- 1998-2000 E36/7 Z3 2.3i
M52B28
The 2,793 cc (170 cu in) version of the M52 debuted in 1995. It has a bore of 84 mm (3.3 in), a stroke of 84 mm (3.3 in) and produces 142 kW (190 hp).[9] 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 Land Rover Defender (South Africa only)
M52TUB28
The "technical update" in 1998 included double VANOS, which improved low rpm 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 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 | |
|---|---|
| Overview | |
| Production | 1996–2000 |
| Layout | |
| Configuration | straight-6 |
| Displacement | 3.15 L (192 cu in) |
| Block material | Cast iron |
| 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), cylinder head and single VANOS. 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)
References
- "3'E36 model selection". www.realoem.com. Retrieved 16 January 2018.
- "Wards 10 best engine". Wardsauto.com. Retrieved 2012-11-23.
- "BMW Classic - Recherche-Client". bmw-grouparchiv.de. Retrieved 20 March 2018.
- "Engines". www.metricmechanic.com. Archived from the original on 2017-09-22. Retrieved 1 October 2017.
- "Engine Management Systems – SIEMENS MS 42.0 Engine Control System" (PDF). p. 51.
- http://www.unixnerd.demon.co.uk/m50.html
- "BMW Heaven Specification Database | Engine specifications for M52 engines". Bmwheaven.com. Retrieved 2012-11-18.
- "BMW Heaven Specification Database | Engine specifications for M52 engines". Bmwheaven.com. Retrieved 2012-11-18.
- "BMW 328i, 1999 E46 technical specifications 96228". Carfolio.com. Retrieved 2012-11-18.
- BMW World - Nikasil, Usautoparts.net, archived from the original on 2013-11-02, retrieved 2012-11-18
- BMW Classics - http://www.bmwclassics.co.uk/about/index.html. "BMW Classics Ezine - News, Reviews & Cars for Sale". Bmwclassics.co.uk. Retrieved 2012-11-18.
- "Engine components / basic engine - Crankcase". bimmernut.com. Archived from the original on 2007-04-07. Retrieved 2016-09-01.
- "BMW World - M52 Engine". Usautoparts.net. Archived from the original on 2012-06-04. Retrieved 2012-11-22.
- Simon Worby, Lestac Ltd (2002). "The BMW Nikasil issue". lestac.co.uk. Archived from the original on 2005-03-06. Retrieved 2016-09-01.
- "BMW World - Nikasil". Usautoparts.net. Archived from the original on 2013-11-02. Retrieved 2012-11-18.
- "BMW S52 Engine". www.mywikimotors.com. Archived from the original on 2017-10-21. Retrieved 6 October 2017.
- "Extreme Engine Tech: Building a BMW S52 – Part 1: The Short Block". www.motoiq.com. Retrieved 6 October 2017.
- "FAQ E36/8 M coupe". BMW M Registry. Retrieved 2012-11-18.
