The M52B28 engine features a cast aluminum alloy cylinder block with Nikasil coated cylinder liners. For countries with high sulfur content in the fuel, the engine version with cast iron sleeves was available. The aluminum cylinder head uses double chain-actuated overhead camshafts (DOHC) and four valves per cylinder (24 valves total). It is equipped with a Siemens MS 41.0 system, DME (Digital Motor Electronics), VANOS (BMW Variable Valve Timing System) and a distributorless ignition system with individual ignition coils for each cylinder.
This engine has a cylinder bore of 84.0 mm (3.31 in.) And a piston stroke of 84.0 mm (3.31 in.). This engine has a compression ratio of 10.2: 1 and a redline of 6,500 rpm. It produced 193 PS (142 kW; 190 HP) at 5,300 rpm of maximum power and 280 N ·m (28.6 kg ·m, 206.4 ft ·lb) at 3,950 rpm of maximum torque.
The engine code breakdown is as follows:
- M52 – Engine family
- B – gasoline
- 28 – 2.5 liter displacement
|Design||Four-stroke, Inline-6 (Straight-6)|
|Displacement||2.8L, 2,793cc (170.44 cu in)|
|Fuel system||Fuel injection system|
|Max. horsepower||193 PS (142 kW; 190 HP) @ 5,300 rpm|
|Max. torque||280 Nm (28.6 kgm, 206.4 ftlb) at 3,950 rpm|
|Order to open fire||1-5-3-6-2-4|
|Dimensions (L x H x W):||–|
|Weight||~ 163 kg (360 pounds)|
The M52B28 cylinder block is cast aluminum alloy with Nikasil coated cylinder liners. Nikasil is an electrodeposited lipophilic nickel matrix silicon carbide coating for engine components. The disadvantage of nickel (and its alloys) is the high sensitivity to sulfur-containing gases. Therefore, for some markets, the BMW M52B28 engine used an aluminum alloy cylinder block with cast iron sleeves.
The cylinder bore is 84.0 mm (3.31 in.) And the piston stroke is 84.0 mm (3.31 in.). The cylinders are exposed to circulating coolant on all sides. Counterbalanced cast iron crankshaft rotates in replaceable split casing main bearings. This motor uses seven main bearings.
Forged steel connecting rods use replaceable split casing bearings at the end of the crankshaft and solid bushings at the end of the piston pin. The pistons are of the three-ring type with two upper compression rings and a one-piece lower oil scraper ring. The fully floating piston pins are retained with snap rings. The compression ratio is 10.2: 1.
|Cylinder Block Alloy||Aluminium alloy|
|Compression ratio:||10.2: 1|
|Cylinder bore:||84.0 mm (3.31 inches)|
|Piston stroke:||84.0 mm (3.31 inches)|
|Number of piston rings (compression / oil):||2/1|
|Number of main bearings:||7|
|Cylinder bore (standard):||84.000-84.010 mm (3.3071-3.3075 inches)|
|Piston Skirt Diameter (Standard):||83.980-83.989 mm (3.3063-3.3066 inches)|
|Piston Pin Outside Diameter:||22,000 mm (0.8661 in.)|
|Piston ring side clearance:||Top||0.020-0.060 mm (0.0008-0.0024 inch)|
|Second||0.030-0.065 mm (0.0012-0.0026 inch)|
|Petroleum||0.020-0.060 mm (0.0008-0.0024 inch)|
|Piston Ring End Gap:||Top||0.100-0.300 mm (0.0039-0.0118 inch)|
|Second||0.200-0.400 mm (0.0079-0.0157 inch)|
|Petroleum||0.250-0.500 mm (0.0098-0.0197 inch)|
|Crankshaft journal diameter:||60,000 mm (2.3622 in.)|
|Crankpin diameter:||45,000 mm (1.7717 inches)|
The cylinder head is made of an aluminum alloy with good cooling efficiency. The M52B28 engine uses chain-actuated dual overhead camshafts and four valves per cylinder. The standard head height is 140.0 mm (5.5118 in). The cylinder head employs a cross flow design for increased power and efficiency. Intake air enters the combustion chamber from one side while exhaust gases exit from the other. This engine is equipped with a unique VANOS (Variable Camshaft Timing) system.
Intake Valves …