The head of the cylinder block or the HBCD is the top of the engine, which serves as an enclosure for the details of the gas distribution mechanism. The HC shall be refitted with bolts or bolts to the cylinder block. The lower part of the block head forms the "ceiling" of the combustion chamber. A single engine has one HBCD, a multiple head for each line of cylinders. The HBCD is produced with precise casting method, mainly made of aluminium alloys. Design of HBCs
Design of HBCs
The head of the cylinder block is very complex. It contains the seats of the valves called "saddles" and the channels in which the intake and discharge valves are moving. The top of the head is fitted with landing points on which the neck of the distribution unit is based.
If the engine is repaired after overheating, the lower surface of the cylinder head shall be milled and slashed at the engine repair centre
In addition, in the case of the SBP, the oiler system and the water-jacket for the coolant have been "laid". Also, spark plugs or filament lamps are sometimes passed through HBCD.
The top of the cylinder head is closed by the cover. It is made of an aluminium alloy or sheet steel and attaches to the head through a gasket or a rubber gasket. The use of the lid is due to the need to service the GRM facility.
Attaching the head of a unit to the cylinder block
Any petrol or diesel engine is built on the principle of compressing the combustion chamber. To avoid compression loss, the HC and the cylinder block are connected by a refractory gasket that prevents leakage of oil and coolant.
If the HBCD engine is removed during the repair process, the pad shall be changed to a new one, and the tightening of the fastening bolts or studs shall be carried out in a fixed sequence. Grave is done with a particular effort and in a certain order. If the tightening of the bolts is too low, the gasket will be leak-tight and will be crushed or lit. As a result, the coolant may be in the cylinders and the engine oil on the outer surface of the unit. To avoid this, it is usually recommended that the bolts be tightened with the cross-bolts of the cross, ensuring that the surface of the block and the head are evenly distributed to each other.
In case of the leak-tightness of the head of the cylinder block, the antifreeze and oil can enter the combustion chamber. If this is the case, the vehicle should be immediately stopped
The moment of tightening of the bolts or stus is shown in the car repair manual. To comply with this parameter, a dynamometer key must be acquired and used.
Characteristics of the head of the cylinder block
As a general rule, the examination of HBOs focuses on the details of the gas distribution mechanism and the degree of wear and tear. No less attention is required for the installation of the HBCD and the head. The sections forming the upper combustion chamber shall be subjected to high heat and mechanical loads. Therefore, in the course of time, cracks may be formed in the head of the head.
One of the signs of disturbance of the leakproofness of the processes taking place in the HBCD is the appearance of the smell of exhaust gas under the hood or traces of engine oil in the coolant. The formation of the HBCD cracks leads to the loss of compression, which in turn reduces the ability to ignite the fuel mix, and the cylinder passes in the cylinder, the engine is overheated.
The exhaust gases under the bonnet and in the passenger compartment may be a symptom of a leak-tightness of the gasket between the HC and the cylinder block
The appearance of cracks in the HBCD can be indirectly measured by the appearance of the exhaust gases. The white thick smoke (and, in fact, vapor) is often a sign of antifreeze into the combustion chamber through a crack in the head.
Unlike the cylinder block, the head is not repaid. In the event of cracks, the HBCs have to change. The ideal replacement option is to purchase the head "assembly", that is, with installed valves and other parts of the valve. If it is not possible to acquire the collected HBOs for some reason, the details extracted from the old head can be rearranged in the new, preseverable.
