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.
E24
The E24 is a 2.4L (2,398cc) version. Bore and stroke is 83.2mm ×73.5mm (3.28in ×2.89in). The engine produces 168bhp (125kW; 170PS) at 5900rpm and 225N⋅m (166lb⋅ft) of torque between 3000 and 5500rpm. The compression ratio is 10.0:1.[1][2]
The E26 is a 2.6L (2,597cc) version. Bore and stroke is 89.9mm ×68.2mm (3.54in ×2.69in). Output is 125kW (170PS; 168bhp) ECE at 5,500rpm 240N⋅m (177lb⋅ft) of torque at 4,500rpm in all applications except in the 2003-2005 W211 E-Class where power rose to 130kW (177PS; 174bhp).[3][4][5] The compression ratio is raised to 10.5:1.[1][6]
The E28 is a 2.8L (2,799cc) version. Bore and stroke is 89.9mm ×73.5mm (3.54in ×2.89in). It produces 201bhp (150kW; 204PS) (W220 S280, R129 SL280 and W210 E280) or 194bhp (145kW; 197PS) (W202 C280) at 5,700rpm and 270N⋅m (199lb⋅ft) of torque between 3,000 and 5,000rpm. The compression ratio is 10.0:1.[1][7]
The E32 is a 3.2L (3,199cc) version. Bore remains at 89.9mm (3.54in) but the engine is stroked to 84mm (3.31in). Output is 215-224 bhp ECE at 5,700rpm (depending on model) with 315N⋅m (232lb⋅ft) of torque at 3,000-4,800rpm. The compression ratio is 10.0:1. It has fracture-split forged steel connecting rods.[1][8]
The E32 Kompressor is a special version of the 3.2L (3,199cc), fitted with a helical Twin-screw type supercharger. The supercharger was developed in conjunction with IHI and features Teflon-coated rotors producing overall boost of 14.5psi (1.00bar) with the factory 74mm clutch-activated pulley. A water-to-air intercooler made by Garrett is fitted beneath the supercharger inside the V, with a 0.8L Heat-Exchanger mounted under the bumper run by an electric water pump. Output is 260kW (354PS; 349bhp) ECE at 6,100rpm with 450N⋅m (332lb⋅ft) of torque at 3,000-4,600rpm. The compression ratio is 9.0:1.[1][9]
The E37 is a 3.7L (3,724cc) version. It retains the stroke of the E32 but is bored to 97mm (3.82in). Output is 173 to 180kW (235 to 245PS; 232 to 241bhp) ECE at 5,750rpm with 344N⋅m (254lb⋅ft) of torque at 3,000-4,500rpm. The compression ratio is 10.0:1.[1][10]
