BMW N74B60 engine

The BMW N74B60 engine was produced in 2009 from a personalized drawing in order to use parts from previous engines to eliminate their inaccuracies and simplify the production stages.

It is a gasoline 12-cylinder V-type motor with a cylinder displacement of 5972 cubic centimeters equal to 6 liters, cylinder diameter of 89 mm and piston stroke of 80 mm. Powertrain performance is 544 horsepower with a torque output of 750 Nm /1500 rpm. Replacing the N 73 unit, many different components are borrowed from the N63 engine. In order to reduce the cost of production of parts and to increase maintainability, all elements of the motor are made of aluminum, the CPG and the main body are combined with any generation of the motor.

The advantages of this motor should be emphasized. These include a vacuum mechanism with a two-stage vacuum pump, a high-precision fuel injection system, an independent mechanism of piezo elements providing ignition, a pair of air heaters operating on the principle of indirect through-air supercharging with indirect cooling and a Double-VANOS gas distribution system. Advanced camshaft and toothed roller chain arrangement, as well as equipping all types of N 74 motor groups with individual oil dispensing and crankcase ventilation mechanism is a distinctive feature of this series. The direct injection mechanism, i.e. jet injection, offers a great opportunity to increase the amount of fuel injected, the duration of injection and the distribution of the mixture in the combustion chamber. The power, torque and fuel metering mechanism benefit from this. The increase in the compression ratio of the mixture due to cooling by the injected fuel is the difference between this motor and turbo engines with an inlet manifold injection mechanism.

The entire range of electronic equipment, which is responsible for the uniformity of gasoline intake and the frequency of ignition, has been improved.  The exhaust system is electronically controlled and at appreciable revs produces a majestic sound accompaniment for the owner, once again reminding him of the twelve cylinders.The unit has its own automatic transmission, but on the basic sets of Bavarians of the No 7 series the typical ZF 8HP is installed.VIN code can be found in the upper part of the engine in the middle between the air intake mechanisms of the superchargers.

The large-scale production of power units of this range coincided with the production of the BMW 7 model. At this point in time, the engines are still relevant and are produced in significant numbers. In case of the need to repair the engine, the automotive market has spare parts available from the manufacturer and similar parts from dealers, without affecting its power and working potential.

Engine specifications N74B60

Disadvantages

Manufacturing from scratch and reasonable innovations in the development of the technical scheme significantly reduced the errors in the motor devices, but with increased use up to the guaranteed service life there were some shortcomings of the power unit.

Let’s look at common problems.

Floating revolutions at minimum crankshaft rpm

Increase in vibration when the unit is at idling temperature causes strong jolts and prevents continuous fuel supply. This is due to the individuality of the Valvetronic mechanism and is considered a factory defect, which was eliminated in the future. Diagnosis of ignition coils every 100000 km, will prevent the problem of floating revs. And in case of failure of oil rings, they should be replaced.Also to eliminate the problem of “floating revolutions” it is necessary to check the serviceability of the flow meter and Valvetronic system.

Uncomplicated structure of the timing mechanism (TDM)

The engine belt is sensitive to the influence of elevated temperatures, so it is necessary to carry out a systematic service inspection and replace the components of the timing unit after 100000 kilometers of mileage. It is believed that the service life of the timing chain is much longer than that of the belt and may well work without interruptions to the full potential of the engine. But in case of increased conditions of use or improper maintenance, its components breakdown or wear of the unit itself occurs. In this case, only its replacement is possible.

Motor decompression

Savings on the use of fuel oil from the manufacturer, incorrect selection of engine oil for the engine, engine operation at low speeds for a long time, unheated engine, traffic jams result in increased formation of coke on the valves and surfaces of the fuel chamber. Due to incomplete oxidation of fuel, soot is formed. Tightness of the intake tract is disturbed due to the loss of valve wall play and piston rings, as a result compression drops due to their “laying down”, or piston rings are destroyed. Removal of soot, carried out in due time change of sealing rings and sealant will help to avoid major repairs, or even replacement of the internal combustion engine.

Cylinder block failure

The engine mechanism works on the basis of 2 control units, if one unit fails, the entire cylinder row is immediately disconnected. Changing the coolant and flushing the mechanism consistently after two years will help to avoid overheating of the engine due to the large number of moving parts of the engine. The manufacturer forbids to modify the engine elements because of the innovations in the technical schemes of this type of engine. Ignoring the manufacturer’s prohibition can lead to expensive repairs or negatively affect the engine’s potential. If the owner still decides to increase traction, adjust the engine functionality to the highest speed, or change the fuel supply settings, the only way to modernize will be chip tuning. Electronic firmware will help to increase the engine power up to 609 hp.

It embodies the reliability of the mechanism and great potential, enduring and relatively voracious. With regular maintenance, it will not cause any problems for its owner.

This engine is installed on the following models:

BMW 7-Series (F01)