Engine block
Most of the main components necessary for the operation of the engine, such as a generator, starter, fuel pump, are attached to the cylinder block. The lower part of the cylinder block forms the engine crankcase. Both types of engines are equipped with replaceable cylinder liners, which can be replaced if the degree of cylinder wear exceeds the maximum allowable limit.
Cylinder head
The cylinder head is attached directly to the cylinder block. The head has channels for air supply and exhaust gas exhaust, valve seats, bearings and guides of the gas distribution mechanism, channels for coolant circulation, prechambers and the combustion chamber itself. The cylinder head gasket, placed between the surfaces of the cylinder head and cylinder block, prevents air and coolant from entering the cylinders. The camshaft is also installed in the cylinder head.
Cylinder liners
Cylinder liners together with the cylinder head form fuel combustion zones. The inner surface of the cylinder liners has a honed surface and is precisely matched to the diameter of the pistons. For cooling, a liquid is used, which washes the outer walls of the sleeves, flowing through the channels made in it.
Pistons
The pistons perceive the pressure of the combustible fuel and transmit it through the connecting rods to the crankshaft of the engine. These types of engines use special pistons with a star-shaped combustion chamber. The main components of a piston are the piston crown, piston ring area, skirt and piston pin bosses. The piston pins are fixed with circlips in the piston bosses. Two top piston rings (O-rings) prevent the breakthrough of gases from the fuel combustion zone into the engine crankcase. lower (oil scraper ring) removes excess oil from the cylinder walls and dumps them into the crankcase.
Connecting rods
The connecting rods connect the pistons to the crankshaft of the engine. The main components of the connecting rod are the upper head of the connecting rod (covers the piston pin), connecting rod stem, lower split end of connecting rod together with cover (covers the connecting rod journal of the crankshaft)
Crankshaft
The crankshaft converts the reciprocating motion of the pistons into rotational motion. Its main parts are root necks (for installation in crankcase plain bearings), connecting rod journals, shaft cheeks (connect the main journals to the connecting rod). On all engines, the crankshaft is mounted on several plain bearings with replaceable liners. The number of main bearings on the 601 and 602 engines is not the same.
Valves
With the help of valves, fresh air is admitted and exhaust gases are released. All the parts involved in opening and closing the valves are called the gas distribution mechanism. All engines covered in this publication have 8 valves (four-cylinder) and 10 valves (five-cylinder).
Camshaft
The camshaft opens and closes the valves in accordance with the work process taking place in the engine cylinders. Each valve is controlled by a hydraulic tappet fitted with a valve clearance compensator and actuated by the camshaft cam. The camshaft, in turn, is driven by the crankshaft via a chain drive. On four-cylinder engines, 5-bearing camshafts are installed, and on six-cylinder engines - 6-bearing camshafts having the same diameter - 31 mm. The lower part of the camshaft bearings is made directly in the body of the cylinder head housing. The camshaft is kept from axial movements by means of a thrust ring fixed on the cylinder head in a special groove in the end part of the cylinder head. On the flange of the camshaft, a mark is made, marking the position of the TDC of the piston of the first cylinder. Next to this risk is the identification number of the camshaft. Using this number and spare parts list, you can choose the right camshaft.
Flywheel
The engines in question are equipped with special sectional (two-mass) flywheels. The meaning of such a flywheel device is to smooth out the torque fluctuations that inevitably occur on the crankshaft due to the peculiarities of the working process of the internal combustion engine, and to prevent further transmission of these fluctuations to the transmission. The use of a flywheel reduces the noise level generated by torsional vibrations. The design of the flywheel is as follows: the front flywheel disk is rigidly fixed to the crankshaft. A torsional vibration damper is mounted on this disk, which is a structure consisting of springs and balancers. The rear of the flywheel is attached to the vibration damper and is not rigidly connected to the front flywheel disc. Thus, the clutch, mounted on the rear flywheel disc, is connected to the engine via a damper.