The BMW S85B50 is a naturally aspirated V10 petrol engine that marked a significant milestone for BMW, replacing the BMW S62 V8 engine in the M5 model. Produced from 2005–2010, it stands as BMW’s first and only production V10 engine. Notably, it was also the first petrol V10 engine available in a production sedan.
A Closer Look at the Engine
The nomenclature of the S85B50 engine sheds light on BMW’s engine classification system. Unlike previous engine codes, the S85 was allocated to the “80s,” reflecting its V10 configuration. The S85B50 engine was primarily featured in the E60 M5 and E61 M5 Touring models, as well as the E63/E64 M6 coupe and convertible.
Design and Specifications
The S85 boasts dual overhead camshafts with four valves per cylinder and incorporates double VANOS for variable valve timing. Constructed from aluminum alloy, both the engine block and cylinder head contribute to its lightweight design.
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Power and Torque
With a displacement of 4,999 cc, the S85 generates an impressive 373 kW (500 bhp) at 7,750 rpm, coupled with a peak torque of 520 N⋅m (384 lb⋅ft) at 6,100 rpm. The engine’s redline extends to 8,250 rpm, highlighting its high-revving nature.
Key Features
Among its notable features are a compression ratio of 12.0:1, electronically actuated individual throttle bodies, and a quasi-dry sump lubricating system. These elements contribute to its exceptional performance and efficiency.
Awards and Recognition
The S85 garnered significant recognition at the International Engine of the Year awards, winning accolades such as Best Performance Engine and Best Above 4.0 Litre across multiple years, reaffirming its status as a pioneering powerplant.
Legacy and Reliability
Despite its groundbreaking design, the S85 faced reliability challenges, including issues with the Vanos system and connecting rod bearings. However, its technological innovations laid the groundwork for subsequent BMW engines.
Enduring Performance and Impact
Despite its challenges, the S85’s legacy endures, as it represents a pinnacle of naturally aspirated engine development. Its blend of power, precision engineering, and distinctive exhaust note continues to captivate enthusiasts worldwide.
Conclusion
In conclusion, the BMW S85B50 engine remains an emblematic example of automotive engineering excellence. While it faced reliability hurdles, its performance capabilities and technological innovations solidified its place in automotive history.