Power units «M62» has a V-shaped arrangement of cylinders at an angle of 90°and is equipped with automatic transmissions, which are installed in the engine compartment along the central axis of the vehicle. The head and cylinder block of these engines are made of light alloy. Engine cylinder blocks have dry thin-walled cast iron liners. The cylinder head is 16-valve, the valves are located at an angle of 39.5°.
Cooling system - closed, liquid, forced. The lubrication system is combined - under pressure and splashing. Power system - injection (injection), electronically controlled. The crankshaft rotates in main bearings. All engines use an overhead valve timing mechanism with an overhead camshaft (DOHC systems) and hydraulic cylindrical pushers, with a chain drive from the engine crankshaft sprocket.
The need to adjust valve clearances during maintenance (THAT) absent. The camshafts are interconnected by a roller chain. The engine has a variable valve timing drive that automatically changes the phase (moment) opening and closing the intake valves by changing the initial position of the camshaft. Such a system has a brand name - «VANOS» (Variable Nockenwellensteuerung).
At the same time, the intake camshaft, depending on the speed of the engine crankshaft, by means of an adjusting mechanism, rotates relative to the drive sprocket in such a way that it provides the optimal moment for opening the valves, thereby achieving optimal valve timing, reducing fuel consumption and meeting exhaust gas toxicity standards (OG). Changing the position of the intake camshafts is carried out by signals from the electronic control unit (ECU), due to the opening and closing of the pressure oil supply valve in the adjusting mechanism of the system (see fig. 4.21).
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 pushers, as well as to the working surfaces of the cylinders from the injectors. The full flow oil filter is mounted separately and connected to the engine with 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 both the generator and the power steering pump. A viscous coupling is installed on the pump shaft, which ensures that the fan turns on depending on the temperature of the coolant. The cooling system is sealed and must be constantly filled with antifreeze.
Separate modifications of these engines have a system of controlled resonant boost by changing the length of the air inlet channels. Engines can only be removed from the vehicle upwards using a special tool and a hoist (hoist) with a carrying capacity of more than 0.5 tons and with the hood of the car completely folded up or removed.
The general layout of the engine and the location of its serial number (1) shown in fig. 4.1.
The electronic engine control system ensures the preparation of the air-fuel mixture and its ignition. On engine models «M62» a modification of the Bosch fuel injection and ignition system is used (Germany), indexed by DME («Digital Motor Electronics» (Motronic) – digital electronic engine management system). In what follows, it will simply be referred to as «DME» or «Motronic». Ignition system fully electronic with individual ignition coils (pic. 4.2) and is controlled from a single ECU 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 this case, in the first case, fuel consumption increases due to power loss, in the second case, there is fuel economy and power increase.
Transmission with manual or automatic control, mounted on the rear wall (at the end) engine and has an all-wheel drive option (4x4). The structural design of the engines differs only in the dimensions of the block and its cylinder-piston group.
Engine Specifications
Model Engines «M62» | B44 | B46 |
Start of release | September 1999 | March 2001 |
Cylinder arrangement | V8/90° | |
Cylinder diameter, mm | 92 | 93 |
Piston stroke, mm | 82,7 | 85 |
Working volume, cm3 | 4398 | 4619 |
Compression ratio | 10,0 | 10,5 |
Compression pressure, kg/cm2 | 12 – 14 | |
Rated power, | ||
– according to the EEC standard, kW | 210 | 255 |
– according to DIN standard, h.p. | 286 | 347 |
Speed, min-1 | 5400 | 5700 |
maximum torque, | ||
– according to the EEC standard, Nxm | 440 | 480 |
– according to DIN standard, kgf∙m | 44,9 | 49,0 |
Speed, min-1 | 3600 | 3700 |
Maximum frequency, min-1 | 6100 | 6500 |
Mixing system | M 7.2 | |
The order of operation of the cylinders | 1–5–4–8–6–3–7–2 | |
Piston-cylinder clearance, mm | ||
- nominal | 0,03 | |
- maximum allowable | 0,10 | |
Cylinder diameter, mm | ||
- nominal | 92,00 | 93,00 |
- intermediate | 92,08 | 93,08 |
– 1st repair size | 92,25 | 93,25 |
Permissible ovality of cylinder mirrors, mm | 0,007 | |
Permissible taper of cylinder mirrors, mm | 0,008 | |
Execution tolerance, mm | 0.00 to +0.014 |