Grinding the cylinder head is an operation, which is performed during the overhaul of the internal combustion engine, moving the motor, etc.. Also, the need to grind the head may arise then, when the so-called "iron" tuning of the internal combustion engine, changes and modifications are made to the design of the engine in order to force the power unit, increases the degree of compression of the motor by reducing the height of the head, etc..
We also recommend reading the article about it, what is the compression ratio of the internal combustion engine. In this article you will learn about the application for the calculation, as well as what is affected by the degree of compression in the internal combustion engine.
As you know, cylinder head (GBC) is one of the main components of the engine. In the head of the modern power unit is the timing belt, the head itself fits snugly to the cylinder block (BC) through the cylinder head gasket, part of the combustion chamber is made in the body of the head, and also pass channels of system of oil and cooling of the engine. For this reason, it is necessary to grind the block head for the best fit, parallel to the grinding of the cylinder head in some cases is carried out and grinding the surface of the cylinder block. Next we'll talk about that, how to grind the cylinder head, as well as how to perform this operation with your own hands.
When the cylinder head needs to be ground
Any defects, which affect the tightness and tightness of the head of the unit to the cylinder block of the engine lead to malfunctions and / or engine malfunctions. The most common cause, on which the head has to be ground as part of engine repair is engine overheating. Violation of the rules of tightening the head during engine assembly is also considered to be a fairly common problem, after which the cylinder head housing is deformed.
We also recommend reading the article about it, how to properly tighten the cylinder head with a torque wrench. In this article you will learn about the recommended effort when tightening the mounting bolts, about the order of tightening and other nuances during this procedure.
In most cases, unscheduled head defects are performed in that case, when there are problems with the gasket of the head of the unit. The specified gasket may burn out, resulting in a breakthrough of gases from the combustion chamber, due to it leaks of motor oil or antifreeze are possible. The exact cause must be determined before replacement, why the cylinder head gasket burned or punctured.
In other words, the gasket is strongly affected by the condition of the block head, to be exact, the connection of the BC and cylinder head planes is broken. In case of defects it is necessary to carry out milling (grinding) cylinder head. The very grinding of the cylinder head, and also the block of cylinders allows to bring to the necessary parameters privalochny plane of cylinder head and BC.
Such repairs are shown to any units regardless, what work is being done (camshaft replacement, gaskets or others). If otherwise, after removal of a head and dismantling it is necessary to pay the increased attention to a condition of a surface in parallel with performance of other operations.
How the block head is ground
Let's start with that, that qualified cylinder head operations and cylinder grinding at home is not recommended, although this is possible and there are several ways. Now let's move on to the procedure itself with that in mind, how it should be performed correctly. First of all, you need to check the plane of the cylinder head. This is done using a long steel ruler, as well as probes (probes can be used to adjust the thermal clearance of the valves). An important condition is that, that the ruler should be smooth, the same thickness, without distortions and defects. The specified ruler should be applied to the lower plane diagonally, then the corresponding probe is inserted into the gaps, which are formed between the plane of the head and the attached ruler. Such actions are performed in turn.
Let's add, that this method of measurement using a ruler is not very accurate, but allows you to quickly check the plane of the block head with your hands right in the garage. If the cylinder head is deformed, then the probes and ruler help to clearly identify defects, and assess the severity of the problem. It should also be noted, that in case of burnout of a lining the most obvious deformations of a privalochny surface will be in that place or near area, where the gasket broke. Indirect sign can also be considered as soot on the pistons in the cylinders located near the place of breakdown.
Let's move on. If defects are found, then the next step is to check the head for cracks. The garage usually uses paint or similar dyes, which covers the body of the pre-washed and cleaned of dirt cylinder head. The dye is then removed from the surface, then on the remains of the dye, who got into a crack, identify problem areas. The method is quite simple, but microcracks or internal damage to the housing with paint can not be determined. For more accurate diagnosis of the tightness of the housing and check for cracking of internal surfaces, you must consult a specialist or have the appropriate equipment at hand. The cylinder head needs to be heated, then the head is placed in a special bath with water. Without going into details, microcracks are manifested by air bubbles, which come out as a result of supply to the housing of the head of the air unit under pressure. Then the crack of a head of the block of cylinders should be carried out (in the presence of such), after which the cylinder head can be ground.
The process of grinding the block head with your own hands is possible in the presence of a milling and grinding machine or experience in performing similar work yourself with the help of a grinding wheel, sandpaper, etc.. In other words, grinding operations are better to trust only the checked and skilled experts. If you decide to repair the engine yourself, then you need to pay special attention to certain subtleties, which are related to grinding the head.
When milling, the most important parameter is the allowable grinding thickness. If easier, you need to know, how much metal can be removed from the surface of a cylinder head. Depth information, on which you can grind the head, should be contained in the technical literature, repair manuals and additional sources for a specific type and model of internal combustion engine. The engine manufacturer must specify this parameter for repair, after which the unit will work properly. If the plane defects are too serious, that is, deep milling to eliminate them may need to remove all allowable stock and exceed the manufacturer's recommended value, then in this case it may be necessary to replace the cylinder head.
As a result
Quite obviously, that the depth of grinding will also directly depend on the further selection of the cylinder head gasket not only on the materials of manufacture (example, metal or reinforced paronite), but also in thickness. This statement is true in that case, if there is a risk after milling, that the timing valve will be too long. In this situation, the thickness removed during grinding is compensated by the increased thickness of the new gasket, installation of double gaskets, as well as shortening the valves.
Finally, let's add, that given that, how much is the grinding of the cylinder head, this repair procedure saves a lot of money and saves the owner from having to install a new head. This is also true for the cylinder block, especially in that case, if internal grinding of the cylinder is required, in which defects appeared.
Qualified work on leak testing, crack repair, boring and grinding of cylinder head or BC allow to receive the checked and completely serviceable detail, which after installation on the car will be a guarantee of the further serviceable work of the internal combustion engine. Example, professionally repaired and properly installed ??the head will last more than tens of thousands of kilometers, provided that the general recommendations during operation and timely maintenance and repair of the engine.