The BMW S85 engine is a V-twin overhead camshaft (DOHC) ten-cylinder piston engine that replaced the S62 engine, produced from 2005 to 2010 and used in the BMW E60 M5, E61 M5 and E63/64 M6. The S85B50 engine is high revving, with a red mark of 8250 rpm on the tachometer. It achieves over 100 hp (70 kW) per liter, and has a very high compression ratio of 12.0:1. Its technology is based on the BMW Williams F1 engine.
Specifications of the S85B50 engine
| Manufacturing | Dingolfing Plant |
| Engine make | S85 |
| Years of manufacture | 2005-2010 |
| Cylinder block material | aluminum |
| Power system | injector |
| Type | V-type |
| Number of cylinders | 10 |
| Valves per cylinder | 4 |
| Piston stroke, mm | 75.2 |
| Cylinder diameter, mm | 92 |
| Compression ratio | 12.0 |
| Engine displacement, cc | 4999 |
| Engine power, hp/rpm | 507/7750 |
| Torque, Nm/rpm | 520/6200 |
| Fuel | 98 |
| Environmental standards | Euro 4 |
| Engine weight, kg | 240 |
| Fuel consumption, l/100 km (for E60 M5) – city – highway – mixed. |
22.7 10.2 14.8 |
| Oil consumption, gr./1000 km | to 1000 |
| Engine oil | 10W-60 |
| How much oil in the engine, liters | 9.3 |
| Oil change is carried out, km | 7000-10000 |
| Engine operating temperature, deg. | – |
| Engine life, thousand kilometers – according to the factory data – in practice |
– 200+ |
| Tuning, hp. – potential – without loss of resource |
750+ n.d. |
| Motor installed | BMW M5 E60 BMW M6 E63 |
| CGPP – 6MKPP – SMG III |
ZF Type-G Getrag 247 |
| Transmission ratios, 6MPT | 1 – 4.05 2 – 2.40 3 – 1.58 4 – 1.19 5 – 1.00 6 – 0.87 |
| Transmission ratios, SMG III | 1 – 3.99 2 – 2.65 3 – 1.81 4 – 1.39 5 – 1.16 6 – 1.00 7 – 0.83 |
Reliability, problems and engine repair of the BMW M5 E60 S85
By tradition, each new M5 becomes bigger and bigger, this applies to the M5 E60 as well, which began to weigh an obscene amount. Consequently, the 400 hp of the former S62 would not be enough to successfully compete with the fast Audi RS6 and Mercedes-Benz E55/E63 AMG. Unlike all previous engines that were developed on the basis of civilian engines, the S85B50 was designed from scratch and used the developments from the sporty P84/5 used in the F1 Williams FW27.
The BMW S85 engine has a lightweight aluminum cylinder block with 10 cylinders arranged with 17 mm offset and 90° camber angle, without liners. Oil nozzles for cooling the pistons and an aluminum crankcase pan are also present. The block is similar in design to the N52. Crankshaft is reinforced forged, connecting rods are light forged, 140.7 mm long, pistons are made of aluminum alloy, under compression ratio of 12 and with a compression height of 27.4 mm.
S85 cylinder heads are aluminum, with 4 valves per cylinder, with hydrocompensators, and with Double-VANOS (similar to the S62). The intake camshaft is 60°, the exhaust camshaft 37°. Camshafts on M5 E60: phase 268/260, lift 11.7/11.5 mm. Inlet valves are 35mm diameter, exhaust valves 30.5mm, stem thickness 5mm. On the inlet there are 10 throttle valves in 2 rows of 5 pieces, for each cylinder its own and receiver optimized for them. Injector capacity is 192 cc. The exhaust manifolds are 5-1, equal-length, one catalytic converter for each. The M5 E60 engine is controlled by DME MS S65 brain.
All this allows you to get 507 hp at 7750 rpm with 5 liters of displacement and spin the engine to the extreme 8250 rpm.
The BMW S85 engine was installed on the M5 E60/E61 and on the M6 E63/E64.
For the younger M3 model in the E92 body, the S85 engine was simplified and named S65B40.
The S85B50 was replaced in 2010, along with the stoppage of production of the M5 E60 and on the BMW M5 F10 stood the new turbocharged V8 S63.
Problems and shortcomings of BMW S85 engines
The M5 E60 motor has a problem with premature wear of connecting rod liners (on all versions of S85B50), which require replacement every 80 thousand kilometers. Such work is better to carry out in advance, so as not to get global trouble with the motor. Vanos also require periodic repair, though not so often. Otherwise, the motor is normal, if it was taken care of, not overheated, serviced qualitatively and in time. Most often things do not happen like this, so before buying an M5 E60 or M6 E63 diagnosis is mandatory.
BMW M5 E60 engine tuning
S85 Atmospheric. Stroker
The S85 motor already from the factory has a high power relative to its displacement and is quite squeezed, but some reserve is still left. The easiest and most commonly used way to raise the output of an M5 E60 is to buy a catalytic converterless sports exhaust (like Supersprint), a Gruppe M intake, a pulley, and appropriate brain tuning. This will give about 50hp. If you add 294/282 camshafts, Dinan throttles and tune to this kit, the M5 E60 will show 580+ hp. This whole kit will allow you to go 1/4 mile in 12 sec. There are also stroker kits that increase displacement from 5 liters to 5.8 liters by installing a long-stroke 82mm crankshaft and 94mm pistons, or standard 92mm pistons (volume will be 5.6 liters). An M5 E60 with a 5.8 liter displacement and with all the above described kit, will show 620-630 hp.
S85 Compressor
A cheaper alternative to the atmospheric tuning of the M5, is the purchase of a compressor kit. The most common and proven option is ESS. Kit ESS S85 VT2, based on Vortech V3Si, will inflate the stock motor 0.5 bar and will allow you to remove 650 hp. Quite a reliable way to get a good amount of power. Don’t forget to get the ESS crank liners. All the more powerful whales require a serious cash injection and involve a loss of reliability.
ENGINE RATING: 5