BMW NEW TECHNOLOGY INTRODUCTION

     The engine is by far the most important component in BMW. And every BMW enthusiast knows that a well maintained engine is good engine. BMW's famous S63TU engine, the 4.4 liter twin-turbo V8 that BMW has used in nearly all of its big performance cars for years now, is a serious contender. The S63 also has top-mounted twin-scroll turbocharger mounted in the vee of the engine and also features variable valve timing and direct injection.

TYPE OF ENGINE USED:

·        BMW S63TU Twin-Turbo V8

·        BMW M6 Gran Coupe (F06) 4.4l V8 (560 HP) - technical specs

Engine specification
Cylinders	V8
Displacement	4395 cm3
Power	412 KW @ 6000 RPM 560 HP @ 6000RPM 553 BHP @ 6000 RPM
Torque	502 Lb-ft @ 1500–5750 RPM 681 Nm @ 1500–5750 RPM
Fuel system	M Twin Power Turbo technology with cross-bank exhaust manifold, Twin Scroll Twin Turbo technology, High Precision Direct Petrol Injection, VALVETRONIC and Double-VANOS
Fuel	Petrol
CO₂ Emission	232 g/km
Performance specification
Top speed	190 mph OR 306 km/h
Acceleration 0-62 Mph (0-100 Km/h)	4.2 s
Fuel consumption specification
City	17 mpg US OR 13.8 L/100Km
Highway	31 mpg US OR 7.6 L/100Km
Combined	24 mpg US OR 9.8 L/100Km

ENGINE OPERATION BMW(VANOS)

Performance, torque, idle characteristics and exhaust emissions reduction are improved by Variable Camshaft Timing. The VANOS system is currently used in all BMW engines.BMW’s Variable Valve Timing system is called VANOS (Variable Nockenwellen Steuerung), and here’s how it works.

The VANOS units are mounted directly on the front of the camshafts and adjusts the timing of the Intake and Exhaust camshafts throughout the entire spread range from retarded to advanced. The ECM controls the operation of the VANOS solenoids which regulates the oil pressure required to move the VANOS units. Engine rpm, load and temperature are used to determine VANOS activation.

The VANOS mechanical operation is dependent on engine oil pressure applied to position the VANOS units. When oil pressure is applied to the units (via ports in the camshafts regulated by the solenoids), the camshaft hubs are rotated in the drive sprockets changing the position which advances/retards the intake/exhaust camshafts timing. The VANOS system is “fully variable”. When the ECM detects that the camshafts are in the optimum positions, the solenoids maintain oil pressure on the units to hold the camshaft timing. The operation of the VANOS solenoids are monitored in accordance with the OBD II requirements for emission control. The ECM monitors the final stage output control and the signals from the Camshaft Position Sensors for VANOS operation.

  

The VANOS unit lifted off, notice how the cam and the cam gear are independent of each other without the VANOS gear in place.  Image courtesy of Beisan Systems.

This is the single VANOS engine (found in M50 engines). It controls the intake cam gear, which is mechanically linked to the exhaust gear with a chain. The key of the VANOS design is that the cam gear and the cam itself are independent, and both have splines.  The gear/cup in the VANOS system inserts in between these two parts, mechanically linking them.  The VANOS gear has two sets of splines, the outer for the cam gear and the inner for the cam itself.  The splines have a twist to them, also known as a helical gear, so as the gear inserts itself further between the cam and cam gear, the relative position changes, if by only a few degrees.

At idle, the gear is retracted.  As the RPM bumps off idle, the cup inserts further into the gear and advances intake valve timing.  This creates intake and exhaust valve overlap, allowing for exhaust gas recirculation (an operation designed to improve emissions while cruising).  When accelerating into the higher RPM ranges, the solenoid closes and the cup retracts once again, reducing overlap and going for max power.  It should be noted that this solenoid gets a real workout, and is a common failure in these engines as they age.

The VANOS solenoid opens, allowing the helical gear cup to push forward and change the orientation of the cam in relation to the gear a number of degrees.

Double VANOS has a hydraulic pod (found in later cars) extending into both cam gears, and has control over both intake and exhaust cam timing independently.  This system is much more advanced than single VANOS, allowing for constantly variable timing.  The ECU can change the intake and exhaust cam timing, and however it so pleases.  Using different maps for different situations ( warm up, cruising, thrashing).

In all practical senses, the system is quite simple and ingenious.  Many of the best car makers do it. All it takes is putting a few different shaped gears together to pull off something amazing.  Now in 2014, you will see that nearly all automakers have some form of variable valve timing, but BMW was one of the few early companies to take full advantage of such a system early on.

VANOS Units

The infinitely variable double VANOS system uses a hydraulic oscillating motor type

VANOS units for the intake and the exhaust cams. Although they have identical function,

the oscillating motor VANOS units are a further development of the variable vane type

motor VANOS units used on previous systems. They are designed as an integrated

component in the chain drive and are mounted with a central bolt on the respective

camshaft. When de-pressurized, a coil spring holds the VANOS unit in the base position.

The VANOS units are controlled by oil pressure from the 4/3 proportional solenoid

valves. The valves are located in the front of the cylinder head and are controlled by the

ECM. The ECM regulates the VANOS based on factors such as engine RPM, load and

coolant temperature.

N52 Hydraulic oscillating motor/VANOS unit

     

Index	Explanation
1	Front plate
2	Locking pin
3	Oil channel
4	Casing with oil ring
5	Pressure chamber for advancing
6	Oscillating rotor
7	Pressure chamber for retarding
8	Oil channel

The VANOS units are controlled by oil pressure from the 4/3 proportional solenoid

valves. The valves are located in the front of the cylinder head and are controlled by the

ECM. The ECM regulates the VANOS based on factors such as engine RPM, load and

coolant temperature.

N52 VANOS system

Index	Explanation
1	VANOS unit, Exhaust
2	VANOS unit, Intake
3	Intake camshaft sensor
4	Exhaust camshaft sensor
5	VANOS solenoid valve
6	VANOS solenoid valve

Here are just some of the benefits of the VANOS.

• It increases torque at lower to mid range engine speeds with no loss of power in the upper range engine speeds.
• It allows for increased fuel economy due to optimized valve timing angles, and reduced emissions.
• You enjoy a smoother idle quality due to optimized valve overlap

Conclusion:

There is no overlooking the BMW M6’s hefty price. However, most M6 owners are extremely satisfied with their purchase. The car’s high-tech features and stunning design make it a dream vehicle. Every driver will get addicted to the M6’s high-revving engine.