BMW S65

BMW S65B40
Overview
Manufacturer	Bayerische Motoren Werke AG (BMW)
Production	2007–2013
Combustion chamber
Configuration	90° V8
Displacement	4.0 L (3,999 cc)
Cylinder bore	92 mm
Piston stroke	75.2 mm
Cylinder block alloy	Aluminum–silicon 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
Successor	BMW S55

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

Engine	Displacement	Power	Torque	Redline	Bore	Stroke	Year
S65B40	3,998 cc (244 cu in)	309 kW (414 hp) @ 8300	400 N·m (300 lb·ft) @ 3900	8400	92 mm	75.2 mm	2007
S65B44	4,361 cc (266 cu in)	331 kW (444 hp) @ 8300	440 N·m (320 lb·ft) @ 3750	8400	92 mm	82 mm	2010

S65B40

Applications:

• 2008-2013 BMW M3 E90/92/93 sedan/coupe/convertible
• 2009-2014 Wiesmann MF4-S GT/Roadster

S65B44

Applications:

• 2010-2011 E92 M3 GTS coupe^[2]
• 2011 E90 M3 CRT

P65B44

Applications:

• 2011 BMW Z4 GTE (non-production)
• 2011 BMW Z4 GT3 (non-production)

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

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

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 wet-sump lubrication system with an oil return pump and a main oil pump replaces the three-pump wet-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]

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

• List of BMW engines
• BMW S85

References

1. http://www.ukipme.com/engineoftheyear/winners_10/3_4.html
2. Tan, Paul. "New BMW M3 GTS with a larger 4.4L V8". Paultan.org. Retrieved 2011-06-18.
3. "Bmw m3 v8". KenRockwell.com. 2007-04-20. Archived from the original on 6 May 2007. Retrieved 2007-04-29.
4. http://www.m3post.com/forums/showthread.php?t=857984
5. "The new BMW M3" (PDF). BMW USA. 2007-04-01. Retrieved 2007-04-29.
6. http://www.bimmerfest.com/pdf/BMW-M3-Aftersales-Training--Information.pdf

External links

• The UnixNerd's BMW S65 engine page with photos, history and common problems.