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The Mercedes-Benz M112 engine is a gasoline-fueled, 4-stroke, spark-ignition, internal-combustion automobile piston V6 engine family used in the 2000s. Introduced in 1998, it was the first V6 engine ever built by Mercedes. A short time later the related M113 V8 was introduced.

Mercedes-Benz M112 engine
Mercedes-benz M112 motor, vE26.jpg
M112 motor in a 2002 C240, 2.6L
Overview
ManufacturerMercedes-Benz
Layout
Configuration90° V6
Displacement2.4 L (2,398 cc)
2.6 L (2,597 cc)
2.8 L (2,799 cc)
3.2 L (3,199 cc)
3.7 L (3,724 cc)
Cylinder bore83.2 mm (3.28 in)
89.9 mm (3.54 in)
97 mm (3.82 in)
Piston stroke68.2 mm (2.69 in)
73.5 mm (2.89 in)
84 mm (3.31 in)
Block materialAluminum
Head materialAluminum
ValvetrainSOHC 3 valves x cyl.
Combustion
SuperchargerIHI Twin-screw type (in some versions)
Fuel systemSequential fuel injection
Fuel typeGasoline
Cooling systemWater cooled
Output
Power output125–260 kW (170–354 PS; 168–349 bhp)
Torque output225–450 N⋅m (166–332 lb⋅ft)

All are built in Bad Cannstatt, Germany except the supercharged AMG C32 AMG, which is assembled in Affalterbach, Germany.

All M112 engines have aluminum engine blocks with a 90° vee angle with silicon/aluminum lined cylinders. The aluminum SOHC cylinder heads have 3 valves per cylinder. All use sequential fuel injection with two spark plugs per cylinder. All have forged steel connecting rods, a one-piece cast camshaft, iron-coated aluminum pistons and a magnesium intake manifold. To deal with the vibration problems of a 90 degree V6, a balancer shaft was installed in the engine block between the cylinder banks. This essentially eliminated first and second order vibration problems (see engine balance). A dual-length Variable Length Intake Manifold is fitted to optimise engine flexibility.

Contents

E24Edit

The E24 is a 2.4 L (2,398 cc) version. Bore and stroke is 83.2 mm × 73.5 mm (3.28 in × 2.89 in). The engine produces 168 bhp (125 kW; 170 PS) between 5500 and 6000 rpm and 225 N⋅m (166 lb⋅ft) of torque between 3000 and 5500 rpm. The compression ratio is 10.0:1.

Applications:

  • 1997-2002 C240
  • 1998-2002 CLK240
  • 1998-2002 E240

E26Edit

The E26 is a 2.6 L (2,597 cc) version. Bore and stroke is 89.9 mm × 68.2 mm (3.54 in × 2.69 in). Output is 125 kW (170 PS; 168 bhp) ECE at 5500 rpm with 240 N⋅m (177 lb⋅ft) of torque at 4500 rpm. The compression ratio is raised to 11.0:1.

Applications:

E28Edit

The E28 is a 2.8 L (2,799 cc) version. Bore and stroke is 89.9 mm × 73.5 mm (3.54 in × 2.89 in). It produces 204 bhp (152 kW; 207 PS) at 5700 rpm and 270 N⋅m (199 lb⋅ft) of torque between 3000 and 5000 rpm. The compression ratio is 10.0:1.

Applications:

E32Edit

The E32 is a 3.2 L (3,199 cc) version. Bore remains at 89.9 mm (3.54 in) but the engine is stroked to 84 mm (3.31 in). Output is 160 to 165 kW (218 to 224 PS; 215 to 221 bhp) ECE at 5700 rpm with 315 N⋅m (232 lb⋅ft) of torque at 3000-4800 rpm. The compression ratio is 10.0:1. It has fracture-split forged steel connecting rods.

Applications:

C32 AMGEdit

 
Supercharged Mercedes-AMG C32 engine

The C32 AMG is a special version of the 3.2 L (3,199 cc) C320, fitted with a helical Twin-screw type supercharger and water-to-air intercooler. The supercharger was developed in conjunction with IHI and features Teflon-coated rotors producing overall boost of 14.5 psi (1.00 bar). Output is 260 kW (354 PS; 349 bhp) ECE at 6100 rpm with 450 N⋅m (332 lb⋅ft) of torque at 3000-4600 rpm. The compression ratio is 9.0:1.

Applications:

E37Edit

The E37 is a 3.7 L (3,724 cc) version. It retains the stroke of the E320 but is bored to 97 mm (3.82 in). Output is 173 to 180 kW (235 to 245 PS; 232 to 241 bhp) ECE at 5750 rpm with 344 N⋅m (254 lb⋅ft) of torque at 3000-4500 rpm. The compression ratio is 10.0:1.

Applications:

See alsoEdit