The BMW S65 engine is a naturally aspirated V8 petrol engine produced from 2007 to 2013. It was primarily fitted to the BMW M3 (where it came to replace the inline six-cylinder BMW S54). There is never a direct replacement for the S65 engine, as the next generation M3 uses a turbocharged six-cylinder engine (BMW S55).
The engine is based on the BMW S85 V10 (in the form installed in the E60 M5), the S65 egine has a similar structure and aluminum construction. Unlike most of the other engines in the BMW M, the S65 and S85 are not based on engines from conventional BMW models.
The S65 received the International Engine of the Year award in the 3 to 4 liter category in 2008, 2009, 2010, 2011 and 2012.
BMW S65 Engine Reviews
The cylinder dimensions on the S65 engine are similar to those in the S85 V10: the bore is 92 mm and the piston stroke length is 75.2 mm. Other similarities in design include individual throttle bodies, knock sensor using ionic control, dual VANOS (variable camshaft control) and 12.0: 1 compression ratio. The red zone on the tachometer starts at 8400 rpm.
To reduce engine weight, a wet lubrication system is used with two electronically controlled evacuation pumps and one main oil pump. It replaces the S85’s three-pump wet system. The dry weight of the S65 engine is 202 kg.
During acceleration, the generator is removed from the engine, allowing maximum power to be used. The generator only supplies energy to the battery during braking, using a system that BMW calls Brake Energy Regeneration.
The Siemens MSS60 engine control unit is based on the Siemens MSS65 used in the S85. The S65 weighs 202 kg, 15 kg lighter than its predecessor, the S54 inline-six.
The cylinder order in the S65 engine is 1-5-4-8-7-2-6-3, which is different from the typical order in other BMW 8-cylinder engines (1-5-4-8-6-3-7-2).
The version of the S65 engine
The S65B40 has a diameter of 92 mm and a stroke length of 75.2 mm.
Found on the car:
- 2008-2013 BMW E90 / 92/93 M3
- 2009-2014 Wiesmann MF4-S
The S65B44 is a larger version of the S65 with a stroke of 82mm. A lightweight titanium exhaust is also used.
Found on the car:
- 2010-2011 BMW E92 M3 GTS
- 2011-2012 BMW E90 M3 CRT (sedan)
The P65 engine is used in motorsport.
Found on the car:
- 2008 BMW M3 ALMS
- 2009 BMW M3 GTR (race car)
- 2010-2015 BMW Z4 GT3 (race car)
- 2013-2016 BMW Z4 GTE (race car)
BMW S65 Engine Problems And Reliability
- Traditionally, every new car model has gotten bigger than the previous one, the M3 is no exception. Compared to the M3 E46, with its S54, the E90 / E92 gains about 200 kg, which means that a completely different engine is required for dynamic driving. BMW M GmbH solved this problems and in 2007 the new M3 was shown with the S65B40 engine (the first V8 on the M3).
- This engine was developed based on the S85B50 by removing two cylinders from the V10 and converting it to a V8, with a capacity of 4 liters. The cylinder block has the same design as on the S85, with a distance between the cylinders of 98 mm, the connecting rods and the pistons as in the M5 engine.
- The cylinder heads are of a similar design, but the Double-VANOS variable valve timing system has been redesigned and there is no separate high pressure oil pump. Adjustment range for intake camshaft 58 °, exhaust 48 °. Camshafts on M3 E92: 256/256 phase, 11.35 / 11.35 mm lift.
- The valves and springs are the same as those used in the S85. At the inlet, 8 throttle valves are used, two rows of 4 pieces each, with a receiver optimized for them, the design is similar to the S85. The standard nozzle capacity is 192 cc. Exhaust manifold 4-1. The Siemens MS S60 is used as a control unit.
- Thanks to all this, the S65B40 engine produces 420 hp. at 8300 rpm and spinning up to 8400 rpm.
- This engine is intended only for the BMW M3 behind the E90, as well as the E92 and E93.
- The BMW S65 was produced until 2013, after which, with the release of the new M3 F80 and M4 F82, the BMW S65 engine was replaced with the turbocharged S55 inline-six.