M52TUB25 from an E46 323Ci (125 kW/245 Nm)
|Manufacturer||BMW, Bayerische Motoren Werke AG|
The BMW M52 is a Straight 6 piston engine. Displacement ranges from 2000 cc to 3200 cc. It is a DOHC 24-valve engine, originally introduced with VANOS Variable Valve Timing. It replaced the BMW M50 engine in 1994 and was replaced in 2001 with the BMW M54 engine. The world market engine used Nikasil lined aluminium cylinders instead of a cast iron cylinder block, resulting in lighter engines. While, the American market engine retained its cast iron block due to the sulfur content of available fuel.
In markets with low-sulfur fuel this engine was very highly regarded and the M52 was on the Ward's 10 Best Engines list for 1995 through to 1998. However, there was criticism of the M52 engine in some markets, especially the UK, which had high levels of sulfur in the petrol during the late 90's. Sulfur acts as a corrosive agent against Nikasil and led to a lot of the early engines having premature bore-liner wear. Fortunately this problem was solved in post-September 1998 cars with the introduction of steel cylinder liners, with the designation M52 TU-3. However problems still present in these engines so affected cars of this period should be bought with caution unless the service history verifies that work was carried out to rectify the problem. The American market M52 used a cast iron block, and so, was unaffected by this problem.
A Technical Update or M52TU version in 1999 added Double-VANOS and other modifications.
|M52B20||2.0 L (1991 cc/121 in³)||110 kW (148 hp) @ 5900||190 N·m (140 ft·lb) @ 4200||6500||1994||66mm (2.6in)||80mm (3.15in)||11.0:1|
|M52TUB20||110 kW (148 hp) @ 5900||190 N·m (140 ft·lb) @ 3500||6500||1998||66mm (2.6in)||80mm (3.15in)||11.0:1|
|M54B22||2.2 L||125 kW (168 hp)||210 N·m (155 ft·lb)||6500||2000|
|M52TUB24||2.4 L (2394 cc/146 in³)||135 kW (184 hp) @ 5800||240 N·m (177 ft·lb) @ 3600||6500||2000|
|M52B25||2.5 L (2494 cc/152 in³)||123 kW (170 hp) @ 5500||245 N·m (181 ft·lb) @ 3950||6500||1995|
|M52TUB25||123 kW (170 hp) @ 5500||245 N·m (181 ft·lb) @ 3500||6500||1998||75mm (2.95in)||84mm (3.31in)||10.5:1|
|M52B28||2.8 L (2793 cc/170 in³)||142 kW (190 hp) @ 5300||280 N·m (207 ft·lb) @ 3950||6500||1995||84mm (3.31in)||84mm (3.31in)||10.2:1|
|141 kW (189 hp) @ 5300||275 N·m (203 ft·lb) @ 3950||6500||1997|
|M52TUB28||142 kW (193 hp) @ 5500||280 N·m (207 ft·lb) @ 3500||6500||1998|
A 2.0 L (1991 cc/121 in³) version was introduced in 1994. Bore is 80 mm and stroke is 66 mm.
2.4 L. For Thai market only.
A 2.5 L (2494 cc) version introduced in 1995. It produces 125 kW (170 hp). Bore is 84 mm and stroke is 75 mm.
A 2.8 L (2793 cc) version also debuted in 1994. It has square 84 mm bore and stroke and produces 193 hp (142 kW).
Power of the 3.2 L version is 321 hp (239 kW). This engine has a bore of 86.4 mm and a stroke of 91.0 mm giving a displacement of 3201 cc. It has a maximum permissible speed of 7600 +/-50 rpm, and a permissible constant speed of 7400 rpm.
The US counterpart shares some of the European version's internal dimensions but uses the more restrictive M52B28 intake manifold and used a cylinder head design more akin to the M52 than to its more powerful European equivalent. Power for the S52B32US is 240 hp (180 kW), and the maximum permissible engine speed was in the 6500 rpm range since it used hydraulic instead of solid lifters.