Mercedes-Benz M112 engine
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 1996, it was the first V6 engine ever built by Mercedes. A short time later the related M113 V8 was introduced.
| Mercedes-Benz M112 engine | |
|---|---|
| Overview | |
| Manufacturer | Mercedes-Benz |
| Production | 1996–2015 |
| Layout | |
| Configuration | 90° V6 |
| Displacement | 2.4 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 bore | 83.2 mm (3.28 in) 89.9 mm (3.54 in) 97 mm (3.82 in) |
| Piston stroke | 68.2 mm (2.69 in) 73.5 mm (2.89 in) 84 mm (3.31 in) |
| Cylinder block material | Aluminum |
| Cylinder head material | Aluminum |
| Valvetrain | SOHC 3 valves x cyl. |
| RPM range | |
| Max. engine speed | 6,000-6,400 rpm |
| Combustion | |
| Supercharger | IHI Twin-screw type (in some versions) |
| Fuel system | Sequential fuel injection |
| Fuel type | Gasoline |
| Cooling system | Water cooled |
| Output | |
| Power output | 125–260 kW (170–354 PS; 168–349 bhp) |
| Torque output | 225–450 N⋅m (166–332 lb⋅ft) |
| Chronology | |
| Predecessor | first Mercedes-Benz V6 engine; before last straight-six engine is the Mercedes-Benz M104 |
| Successor | Mercedes-Benz M272 |
All are built in Bad Cannstatt, Germany, except the supercharged C32 AMG and SLK32 AMG, assembled in Affalterbach, Germany.
All M112 engines have silicon/aluminum (Alusil) engine blocks with a 90° vee angle. 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.