The engine has a variable valve timing drive that automatically changes the phase (moment) opening and closing the intake and exhaust valves by changing the initial position of the camshaft. Such a system has a brand name - «Doppel VANOS» (Doppel Variable Nockenwellensteuerung»). In the technical literature, there is a designation - «Ві-Vanos». The engine also has a variable intake valve lift system - Valvetronic, which allows you to adjust the engine power, eliminating the use of the throttle. The throttle valve is retained in the engine design as an element of duplication in the engine management system.
The pressurized oil supply to the engine is provided by a mechanical oil pump with internal gears. The oil pump is chain driven from the crankshaft sprocket and is located in the crankcase oil pan. Oil is taken from the crankcase by a pump receiver and is supplied through channels and pipelines to the bearings of the crankshaft and camshafts, hydraulic compensators, as well as to the working surfaces of the cylinders from the injectors. The full-flow oil filter and pump are mounted on a separate frame and connected to the engine channels by hoses.
The centrifugal type liquid cooling pump is mounted in the front wall of the engine block. Its drive is carried out by a V-belt from the engine crankshaft pulley. The same belt is used as a drive for the generator and power steering pump. A viscous coupling is installed on the pump shaft, which ensures that the fan is turned on, depending on the temperature of the coolant. The cooling system is sealed and must be constantly filled with antifreeze.
Table 5.1. engine specifications
Model engines | N62B44 | N62B48 |
Automobile model | X5/4.4i | X5/4,8is |
Cylinder arrangement | V8/90° | |
Cylinder diameter, mm | 92,0 | 93,0 |
Piston stroke, mm | 82,7 | 88,3 |
Working volume, cm3 | 4398 | 4799 |
Compression ratio | 10,0 | 10,5 |
Compression pressure, kg/cm2 | 9/18* | |
Rated power, | ||
– according to the EEC standard, kW | 235 | 265 |
– according to DIN standard, h.p. | 320 | 360 |
Speed, min-1 | 6100 | 6200 |
maximum torque, | ||
– according to the EEC standard, N·m | 440 | 500 |
– according to DIN standard, kgf·m | 44,9 | 51,0 |
Speed, min-1 | 3600 | 3500 |
Maximum frequency, min-1 | 6100 | 6500 |
Maximum spread of compression pressure in all cylinders | 1,5 | |
Mixing system | ME9.2.1 | |
The order of operation of the cylinders | 1–5–4–8–6–3–7–2 |
*) The numerator is the compression value at minimum valve lift, the denominator is at maximum valve lift.
The engine has a system of controlled resonant boost, by changing the length of the intake channels. Engines can only be removed from the vehicle upwards, using a special tool and a hoist (hoist), with a carrying capacity of at least 0.5 tons, with the hood of the car completely folded up and fixed with a special device.
The general layout of the engine and the location of its serial number are shown in fig. 5.1.
The engine uses a modification of the Bosch fuel injection and ignition system (Germany), indexed by DME («Digital Motor-Elektronik»), Motronic models - a digital electronic engine management system, the ME9.2.1 series, which will be referred to as DME in the future. Ignition system electronic, with individual ignition coils (see fig. 4.2) for each cylinder, and controlled by an electronic unit from the DME.
Engines use gasoline with an octane rating as fuel (ROZ) 95, however, the ability to dampen detonation on individual cylinders allows the use of fuels with octane numbers from ROZ 91 to ROZ 98. In the first case, fuel consumption increases due to power loss, in the second case, there is fuel economy and power increase.
The transmission with manual or automatic control is mounted on the rear end of the engine and has all-wheel drive (4x4) with torque distribution.