BMW S85
Encyclopedia
The BMW
S85B50 is a DOHC 40-valve V10
automotive piston
engine
present in the E60 M5 sedan, E61 M5 touring and E63/64 M6 coupé. It was derived directly from BMW's Formula 1 racing division.
At its introduction in 2005, the S85 was the most powerful engine among German manufacturers, although Mercedes-Benz and Audi have since developed engines that have surpassed it in output. Production of the S85 ceased in 2010.
s are designated by "60s" and V12 engine
s labeled as "70s", the S85 was badged with an "80" despite it having fewer cylinders than the "70"-series engines.
The S85 spawned a related S65
V8 engine for the 2008 BMW M3
. Although the "65" designation is apparently out of order compared to the other V8 engines (which follow "62"
and "63"
sequentially), the S65 was badged such since its design is largely derived from the S85 minus two cylinders, and not related to BMW's other V8s.
Unlike other BMW engines, there are no mass market "M" or "N" versions of the S85 and S65 and nor is there any shared parts, as these engines are used exclusively in BMW M
performance vehicles.
. Gerd Richter, the head of BMW M, defended the decision to use a single-clutch sequential manual gearbox rather than a twin-clutch unit
, saying "True, the dual-clutch system has a smoother automatic mode, and it performs seamless upshifts. For a 7-series
, this may be the way to go. But an M car should always combine efficiency with emotion. That's why there are six shift speeds to choose from, from velvet glove to iron fist. That's why we cut the torque into seven slices. That's why we added special features like a hill holder, a designated drive program for steep climbs and descents, and a downshift assistant, which briefly dips the clutch to avoid destabilizing wheel spin." The SMG III transmission, while responsive at the track, has been criticized for its general lack of smoothness in everyday driving, and by 2010 it was considered outdated, as most manufacturers were using dual clutch transmission
s instead.
BMW announced in October 2006 that a 6-speed conventional manual transmission
would be available in North America. This became the base transmission in these markets, with the SMG III as an option. The 6-speed manual transmission was marginally slower, since initially the dynamic stability control could not be disengaged unlike the SMG version. A software update was later released in 2008 to allow manual transmission vehicles the ability to deactivate the dynamic stability control.
awards in the following 4 categories:
In 2006 the S85B50 won several International Engine of the Year
awards, winning in the following 3 categories:
In 2007 the S85B50 won several International Engine of the Year
awards, winning in the following 2 categories:
In 2008 the S85B50 won an International Engine of the Year
award, winning in the following category:
BMW
Bayerische Motoren Werke AG is a German automobile, motorcycle and engine manufacturing company founded in 1916. It also owns and produces the Mini marque, and is the parent company of Rolls-Royce Motor Cars. BMW produces motorcycles under BMW Motorrad and Husqvarna brands...
S85B50 is a DOHC 40-valve V10
V10 engine
A V10 engine is a V engine with 10 cylinders in two banks of five with a distinct exhaust note.- Mechanics :The V10 is essentially the result of mating two even-firing straight-5 engines together. The straight-5 engine shows first and second order rocking motion...
automotive piston
Piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from...
engine
Engine
An engine or motor is a machine designed to convert energy into useful mechanical motion. Heat engines, including internal combustion engines and external combustion engines burn a fuel to create heat which is then used to create motion...
present in the E60 M5 sedan, E61 M5 touring and E63/64 M6 coupé. It was derived directly from BMW's Formula 1 racing division.
At its introduction in 2005, the S85 was the most powerful engine among German manufacturers, although Mercedes-Benz and Audi have since developed engines that have surpassed it in output. Production of the S85 ceased in 2010.
Nomenclature
As the S85 was BMW's first V10 engine, it was given a new series in the nomenclature. While V8 engineV8 engine
A V8 engine is a V engine with eight cylinders mounted on the crankcase in two banks of four cylinders, in most cases set at a right angle to each other but sometimes at a narrower angle, with all eight pistons driving a common crankshaft....
s are designated by "60s" and V12 engine
V12 engine
A V12 engine is a V engine with 12 cylinders mounted on the crankcase in two banks of six cylinders, usually but not always at a 60° angle to each other, with all 12 pistons driving a common crankshaft....
s labeled as "70s", the S85 was badged with an "80" despite it having fewer cylinders than the "70"-series engines.
The S85 spawned a related S65
BMW S65
The S65 is a naturally aspirated DOHC 32-valve automobile V8 engine from BMW.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 as a replacement for the S54 straight-6...
V8 engine for the 2008 BMW M3
BMW M3
The BMW M3 is a high-performance version of the BMW 3 Series, developed by BMW's in-house motorsport division, BMW M. M3 models have been derived from the E30, E36, E46 and E90/E92/E93 3-series, and sold with coupé, sedan and convertible body styles...
. Although the "65" designation is apparently out of order compared to the other V8 engines (which follow "62"
BMW N62
The N62 is a V8 from BMW, built in Munich, Germany. It has an Alusil aluminum engine block and aluminum DOHC cylinder heads.It uses SFI fuel injection, has 4 valves per cylinder with BMW's double-VANOS and Valvetronic technologies and features fracture-split forged powdered metal connecting...
and "63"
BMW N63
The N63 is a family of 4.4L, direct-injected, twin-turbocharged V8 automobile engines produced by BMW since 2008.-Specifications:The N63B44 features a reverse-flow air design in which the turbochargers are mounted in the engine valley and the intake manifolds are located on the sides of the block...
sequentially), the S65 was badged such since its design is largely derived from the S85 minus two cylinders, and not related to BMW's other V8s.
Unlike other BMW engines, there are no mass market "M" or "N" versions of the S85 and S65 and nor is there any shared parts, as these engines are used exclusively in BMW M
BMW M
BMW M GmbH is a subsidiary of German car manufacturer BMW AG.BMW M, also known as M-Technik or just "M" was initially created to facilitate BMW’s racing program, which was very successful in the 1960s and 1970s...
performance vehicles.
Technology
The S85B50 is a high-revving engine designed to utilize power from a wide rev band. Having a redline of 8250 rpm, it achieves over 100 bhp/litre which is an incredible feat for a naturally aspirated production engine, as other manufacturers have used supercharging or turbocharging to reach a similar output level. The S85 features a very high compression ratio of 12.0:1, exceeding the previous S54's ratio of 11.5:1- 5.0 Litre V10 engine, 90 degree bank angle, 507 hp @ 7750rpm/520 newton metre torque @ 6100rpm
- Cast aluminum block with bed plate design split at the crankshaft axis.
- Cast aluminum heads with four valves per cylinder and CNC machined ports and combustion chambers. Valves are actuated through non-rotating inverted bucked cam followers.
- Oil-cooled, forged aluminum pistons from Mahle Motorsport
- Forged steel crankshaft with counterweights, shared crankpins producing an uneven firing interval of 90 or 54 degrees.
- Double VANOSVANOSVANOS is an automobile variable valve timing technology developed by BMW in close collaboration with Continental Teves. VANOS varies the timing of the valves by moving the position of the camshafts in relation to the drive gear...
system which varies both intake and exhaust cam phasing
- 10 individual electronically controlled throttle butterflies
- Knock sensors have been eliminated by utilizing the "ionic current" measuring system. Using the ionic current system, engine misfires as well as knock can be measured simultaneously. The ionic current is measured by passing a low voltage across the spark plugs immediately following the ignition spark.
- Quasi-dry sump lubricating system
- The firing order for the S85 engine is 1-6-5-10-2-7-3-8-4-9. http://users.on.net/~sa145/E60_M5_Complete_Vehicle.pdf
Transmission
The S85 was initially only offered with the new Getrag SMG III single-clutch seven speed semi-automatic transmissionSemi-automatic transmission
A semi-automatic transmission is an automobile transmission that does not change gears automatically, but rather facilitates manual gear changes by dispensing with the need to press...
. Gerd Richter, the head of BMW M, defended the decision to use a single-clutch sequential manual gearbox rather than a twin-clutch unit
Dual clutch transmission
A dual clutch transmission, commonly abbreviated to DCT , is a differing type of semi-automatic or automated manual automotive transmission. It utilises two separate clutches for odd and even gear sets...
, saying "True, the dual-clutch system has a smoother automatic mode, and it performs seamless upshifts. For a 7-series
BMW 7 Series
The BMW 7 Series is a line of full-size luxury vehicles produced by the German automaker BMW. Introduced in 1977, it is BMW's flagship car and is only available as a sedan or extended-length limousine...
, this may be the way to go. But an M car should always combine efficiency with emotion. That's why there are six shift speeds to choose from, from velvet glove to iron fist. That's why we cut the torque into seven slices. That's why we added special features like a hill holder, a designated drive program for steep climbs and descents, and a downshift assistant, which briefly dips the clutch to avoid destabilizing wheel spin." The SMG III transmission, while responsive at the track, has been criticized for its general lack of smoothness in everyday driving, and by 2010 it was considered outdated, as most manufacturers were using dual clutch transmission
Dual clutch transmission
A dual clutch transmission, commonly abbreviated to DCT , is a differing type of semi-automatic or automated manual automotive transmission. It utilises two separate clutches for odd and even gear sets...
s instead.
BMW announced in October 2006 that a 6-speed conventional manual transmission
Manual transmission
A manual transmission, also known as a manual gearbox or standard transmission is a type of transmission used in motor vehicle applications...
would be available in North America. This became the base transmission in these markets, with the SMG III as an option. The 6-speed manual transmission was marginally slower, since initially the dynamic stability control could not be disengaged unlike the SMG version. A software update was later released in 2008 to allow manual transmission vehicles the ability to deactivate the dynamic stability control.
Awards
In 2005, the first year that it was nominated, the S85B50 won four different International Engine of the YearInternational Engine of the Year
The International Engine of the Year is an annual competition for automotive industry internal combustion engines, judged by a panel of automobile journalists from around the world. It is organised by the United Kingdom's largest technical motoring, aerospace and traffic management publication...
awards in the following 4 categories:
- International Engine of the Year, BMW 5.0 Litre V10 (M5,M6)
- Best Performance Engine
- Best New Engine
- Best Above 4.0 Litre
In 2006 the S85B50 won several International Engine of the Year
International Engine of the Year
The International Engine of the Year is an annual competition for automotive industry internal combustion engines, judged by a panel of automobile journalists from around the world. It is organised by the United Kingdom's largest technical motoring, aerospace and traffic management publication...
awards, winning in the following 3 categories:
- International Engine of the Year, BMW 5.0 Litre V10 (M5,M6)
- Best Performance Engine
- Best Above 4.0 Litre
In 2007 the S85B50 won several International Engine of the Year
International Engine of the Year
The International Engine of the Year is an annual competition for automotive industry internal combustion engines, judged by a panel of automobile journalists from around the world. It is organised by the United Kingdom's largest technical motoring, aerospace and traffic management publication...
awards, winning in the following 2 categories:
- Best Performance Engine
- Best Above 4.0 Litre
In 2008 the S85B50 won an International Engine of the Year
International Engine of the Year
The International Engine of the Year is an annual competition for automotive industry internal combustion engines, judged by a panel of automobile journalists from around the world. It is organised by the United Kingdom's largest technical motoring, aerospace and traffic management publication...
award, winning in the following category:
- Best Above 4.0 Litre