BMW S65

BMW S65B40O0
Overview
Manufacturer Bayerische Motoren Werke AG (BMW)
Production 20072013
Combustion chamber
Configuration 90° V8
Displacement 4.0 L (3,999 cc)
Cylinder bore 92 mm
Piston stroke 75.2 mm
Cylinder block alloy Aluminumsilicon alloy
Cylinder head alloy Aluminum alloy
Valvetrain DOHC
Compression ratio 12.0:1
Combustion
Fuel system Fuel injection
Management MSS60 ECU
Fuel type Gasoline
Cooling system Water-cooled
Output
Power output 309 kilowatts (414 hp)
Torque output 400 N·m (295 lb·ft)
Dimensions
Length 734 mm
Chronology
Predecessor BMW S54

The BMW S65 is a V8 DOHC piston engine which replaced the (straight-6) S54 and was produced from 2007–2013.

Derived from the BMW S85 V10 engine used in the M5/M6, it shares the same basic architecture and aluminium construction. It was introduced in the E92 M3 and was chosen as International Engine of the Year for the 3.0 to 4.0 L category in 2008, 2009, 2010,[1] 2011, and 2012.

Models

EngineDisplacementPowerTorqueRedlineYearBoreStroke
S65B403,998 cc (244 cu in)309 kW (414 hp) @ 8300400 N·m (300 lb·ft) @ 39008400200792mm75.2mm
S65B444,361 cc (266 cu in)331 kW (444 hp) @ 8300440 N·m (320 lb·ft) @ 37508400201092mm82mm

S65B40

Applications:

S65B44

Applications:

Development

The S65 engine was developed due to its S54 predecessor having reached the end of its development potential and being unable to meet increasingly stringent Euro V and California Air Resources Board (CARB) emissions regulations.

Design

The S65 shares the same 92 mm (3.6 in) bore and 75.2 mm (3.0 in) stroke cylinder dimensions with the S85 V10, along with the Double-VANOS variable valve timing system and 12.0:1 compression ratio.

A conventional wet-sump lubrication system with two oil pumps replaces the three-pump dry sump system used on the V10, further decreasing weight.[3][4] The alternator disconnects from the engine during acceleration to maximise power, only charging the battery during braking and decelerating whenever possible, in a system BMW calls Brake Energy Regeneration.[3]

S65 engine with the top plastic air plenum removed to reveal the 8 individual throttle bodies.

An updated version of the Siemens MSS65 ECU (used in the S85 V10) is fitted to the V8. Claimed to be capable of more than 200 million calculations per second, the new ECU (known as the MSS60) comfortably exceeds the 25 million calculations of which the S54's ECU was capable. The MSS60 was actually produced before the MSS65 control unit, although it was not put into production vehicles until the M3 in 2007. The newer M3 control units are manufactured by Continental and are no longer labeled Siemens.

The resulting engine weighs 202 kg (445 lb): 15 kg (33 lb) lighter than the straight-6 engine it replaces, while also being shorter.[5]

The firing order for the S65 engine is 1-5-4-8-7-2-6-3, which is different from the typical BMW V8 firing order of 1-5-4-8-6-3-7-2 [6]

See also

References

External links

Wikimedia Commons has media related to BMW S65 engine.