How to determine the crack in the head. Diagnostics of the GBC - check for microcracks. Metal or paronit gasket GBC: What is better

Repair of the cylinder head as you understand this long tedious, requiring special care of work. If you think that it is like two fingers to rub, they are very mistaken. I'll tell you why. To begin with, you need to remove the head, on some cars it is easier to remove the engine entirely, rather remove only the head. Removed head It is necessary to carefully wash the diesel or better than gasoline, and It would be quite good to put it in a bath with caustic soda.

Next, visual inspection and diagnosis. Aluminum heads have such a feature or property - after overheating, the plane of the cylinder head is a bit twisted, after which gLP gasket (Cylinder heads) begins to skip oil and water in small or large quantities. Oil and coolant can be seamless to outward (as a result, the engine becomes dirty and all its species shows that it needs to be repaired) and in the engine where the coolant will fall into the pallet of the crankcase and mix with motor Oil, Turning into a motor poison that enhances the engine of your car very quickly.

It is necessary to check the plane, for this I have a special ruler perfectly flat, made at the plant of ultra-precision devices specifically for measuring the irregularities of flat surfaces. What can measure the plane of the GBC man who does not have such an appliance, I don't even know ... But if you still find something that is suitable with a perfectly smooth surface, then you do the following: 1. Employ the plane of the head from Nagara, scale and residues of the old gasket. 2. On the cleaned plane of the GBC, put your "measuring instrument" along the length of the head and see the gap between the device and the plane of the GBC, move the device throughout the plane, put diagonally and look out the gap again. If there is no gap, then the plane of the GBC is in order; If there is a 0.5-1mm clearance, then the head is better to finish or if finance is allowed to put a new one. If the gap is more than 2mm, then the head needs to be restored, that is, to try out. When the GBC is moving, a twisted layer of the plane is removed, after which the GBC can be used again. P.S. The driver who checks the oil in the motor at least once a week, seeing that oil became twice as much, and the radiator is half empty just rolling into the radiator still toxol and go further, in a few days it will get to repair and spare parts.

yamotorist.ru.

How to check the head of the cylinder block on the VAZ 2114 - repair 2114

To perform work on checking the head of the cylinder block, you will need:

• set of flat probe
• special template or widespread line

Video on the topic:

Remont2114.ru.

Checking the head of the cylinder block

Remove the entire tart from the walls of the combustion chambers (Fig. 2.121). Check the cylinder head for cracks in intake and outlet channels, combustion chambers and on the surface of the head. Using the calibration line and probe, check the flatness of the surface of the head connector with a block of cylinders a total of 6 places. If deformation exceeds the limit value, correct the sealing surface with the plate and emery paper approximately No. 400 (waterproof sandpaper with silicon carbide): Wrap the plate with sandpaper and stabbing the sealing surface to remove the protruding places. If after this measurement results do not correspond to the norm (exceed the limit value), replace the head of the cylinder block. The leakage of combustion products through the plane of the head connector and the cylinder block is often a consequence of deformation of compacted surfaces: such a leak leads to a decrease in engine power (Fig. 2.122). The limit value of the deviation of the sealable surface of the head of the cylinder block from the plane: 0.03 mm. The deformation of the selection surfaces of the collectors: Check the seating surfaces of the collectors on the head of the cylinder block using the calibration line and the probe to determine whether the editing of the surface is possible or it is necessary to replace the cylinder block head (Fig. 2.123). The limit value of the deformation of the seating surfaces of intake and exhaust manifolds on the head of the cylinder block: 0.05 mm.

carmanz.com.

How to check the head of the cylinder block after grinding?

Check the cylinder head in principle and not so difficult.

Clean the GBC from dirt, oil, chips. Carefully examine the head on all sides to ensure that there are no shells and cracks.

In specialized workshops, the block head plane is checked by a special template.

At home when this template is not, you can check the flatness with a metal wide long line. It must be applied to the plane of the head of the head, the figure shows where to make applying

And check the gaps of the dipstick. The clearance is checked throughout the perimeter ideally - the gaps should not be. But if the clearance is no more than 0.01 mm, then it is allowed.

We emphasize and allocate: a new or polished head of the cylinder block, the clearance is not more than 0.01 mm.

Because with the gaps of 0.1mm left (in some repair instructions, it is precisely this typo) that will be a high probability of breaking the block of the block head. And this is again the analysis and repair of the GBC, or even the engine, up to its replacement.

The head of the cylinder block must also be checked for tightness. This can be done for example the cerosene bay in the cooling cavity, shutting the fluid feeding hole. Cooking is made also with compressed air about 1.5 - 2 atmospheres, but it certainly needs a compressor, bath, that is, certain conditions.

When the head is tested passed, and is again tested for flatness, on tightness, then you can install the valve, pre-rapidly, and after the assembly, also check them on the kerosene. If kerosene does not proceed for about half an hour, then it is already well the valve prortes.

Cylinder block is clear, too, do not forget to clean from a car, rinse from dirt, clean and blow all channels. Wash the crankcase, the admissions of the oil pump, make sure the performance of the oil pump itself. Well, you can proceed to the final assembly of the motor.

Frantishek Caper,
Engineer maintenance Federal Mogul (USA)

Yuri Chapel,
Leading expert of the company "Mechanics"

Automotive engines - gasoline and diesel - from year to year become increasingly powerful, economical and satisfy increasingly stringent environmental standards. These characteristics are determined primarily by the efficiency of fuel combustion in cylinders, which, in turn, largely depends on the design and parameters of the head of the cylinder block (GBC), from the health and coordinated work of the elements of the gas distribution mechanism. Sooner or later, it is necessary to repair this important engine assembly.

There is a wide variety of GBC design solutions, and in each case the algorithm for removing the unit from the engine and its disassembly has its own characteristics. However, there are some general rules.

Before disassembling the head of the cylinder block

Before disassembling the GBC, it is necessary:

• Remove all holders, sensors and other attached electrical equipment. If you are dealing with a GBC diesel engine with electromagnetic nozzles, they also need to be dismantled (pump-nozzle pump optional).
• Before removing the head from the block, it is necessary to ensure the visibility of the labels used to adjust the gas distribution mechanism. If it is impossible, the details of the gas distribution mechanism should be melted accordingly.

Further actions are described on the example of the GBC with the upper arrangement of the camshaft (OHC):

• Loosen the fastening bolts of the block head cover in order similar to the order of their tightening when mounting. Remove the GBC.
• Denote the bearing caps (if applied) of the camshaft to determine their correct position when assembling.
• Remove the camshaft bearings covers, slightly turning them.
• Remove the camshaft and bearings.
• Remove hydrocomathers and pushers (depending on the design of the block head). If it is assumed to be used to use them, then note the jobs of each.
• With the help of the appropriate device, squeeze the springs of the valves and remove the crackers, the springs plates and the springs themselves. Put the details in the order of their dismantling.
• Remove oil pulp with valve rods (if installed).
• Turn over the head, remove the valves, noting the places where they were installed.
• Save all components until it is accurately set to match the size of all new and replaceable parts.

Then make cleaning the head of the cylinder block. The assembly needs to be carried out in the reverse order.

Cleaning

For cleaning the head head, the following methods can be used:

• sandblasting;
• "Cold" flushing;
• "hot" flushing;
• cleaning with ultrasound.

More often than others applies the car wash in water using special detergents. It is necessary to ensure that the detergents do not contain chemical elements capable of damaging gBC details. Special attention Requires the cleaning of the components of the aluminum head of the cylinder block.

During purification using abrasive components from surfaces of parts of the head, a layer of material is removed, so care must be taken - an excessively intense or prolonged impact may result in their damage.

The most frequent defects

The most commonly encountered defects of the parts of the cylinder head include:

• valve's start as a result of the inconsistency of the shape (material) of the saddle and the valve or strong wear of the saddle;
• damage to the inner surface of cylinders, pistons, piston rings and engine bearings caused by detonation combustion or premature ignition fuel mixes;
• deformation and progress of the railway plane of the GBC as a result of leakage exhaust gases or coolant due to the effects of temperature above the maximum allowable, violation of the normal mode of operation of the combustion chamber or cooling fluid circulation;
• damage to the gasket of the GBC as a result of its improper installation, including due to the use of inappropriate moments or violation of the order of tightening bolts;
• poor-quality mechanical processing of cabbage planes and engine cylinders block before replacing the gasket;
• damage to the surface of parts as a result of electrolysis or chemical reactions, as a result of the use of abrasive material;
• the destruction of the material of the details due to the defect of the injection system.

Methods for finding defects CBC

Many defects can be identified visually and decide on further repair, without resorting to expensive diagnosis. Carefully inspect the node on the subject of the rogar, the cracks between the saddles. On diesel engines, under the operating conditions, shallow cracks are allowed between saddles that do not violate tightness. If you plan to use former cams, guides, hydro pulls and other parts, it is recommended to mark the places of their installation on the engine.

For accurate and fast diagnostics of the GBC, several uncomplicated, but reliable ways are used. One of them - magnetic Powder Detection (Only for cast iron GBC). The essence of it is as follows.

From different sides, the GBC is installed magnets and the iron powder pour on the head surface. Powder particles under the action of a magnetic field will be located in cracks, sinks and other damage with greater density, making them easily noticeable.

Detect cracks and cast iron, and in aluminum heads can be used painting liquid. On the carefully cleaned surface of the head of the cylinder block, you need to apply in painting liquid and wait for about five minutes. After removing the surplus "paint" cracks (if, they are) will become naked eye. As a "developer" defects, you can also use chalk.

Pressure test method Designed to determine cracks in the cooling / lubrication system of the GBC. It can be implemented in two ways: with immersion and without immersion of the unit into water.

In the first embodiment, the block head is installed in the device, hermetically closing all channel circuit channels of the checked system - the coolant system or the lubrication system. Then air is supplied to this circuit, and a soap aqueous solution is supplied to the surface of the aggregate. The air bubbles are determined by the place where there is a crack. If necessary, the tightness of the channel channels of another system is also checked. This method is not absolutely reliable, since in some cases the cracks are manifested only after installing the head to the cylinder block.

In the second version of the CHC with hermetically closed cooling fluid / oil circuit channels immersed in a vessel with hot water. A compressed air is supplied to the circuit and the air bubbles determine the place where there is a crack. If necessary, similarly check the tightness of the channel channels of another system. The advantage of this method is that it makes it possible to check the GBC under conditions of different temperatures. However, it is not absolutely reliable, since in some cases the defects give you to know about yourself only after installing the head on the cylinder block.

Relatively quick way to detect cracks in GBC - with a vacuum tester. The method allows you to identify the presence of a crack, but does not make it possible to determine the specific place of the defect.

In addition to the lack of mechanical damage, it is necessary to check the geometry and purity of the railway plane of the GBC and the cylinder block: straightness in longitudinal and transverse directions, roughness and waviness. With a minor deviation from the norm, if the manufacturer involves the mechanical processing of the plane, the defect is eliminated by milling or grinding. If the deflection of the GBC is more permissible plant, they replace the part.

Defects of the valve mechanism parts

After the visual inspection and the tests described above, the valve diameter of the valve mechanism are monitored to diagnose the valve mechanism.

The most frequent valve defects (their probable causes):

• defects of the Support Surface (too large clamping valve spring force, excess of the maximum permissible rotational speed crankshaft, overheating of the engine, the use of parts from materials that are not compatible with unleaded gasoline);
• the formation of "cups" on the valve head (engine overheating along with an excessively strong plugging force of the valve spring or high speed landing of the valve head in the saddle);
• jamming the rod in the guide valve (too small gap between the valve rod and the guide sleeve; excessive oil pollution; engine overheating; incorrect adjustment of the exhaust valve);
• valve rod breakage (strong guide wear and, as a result, a non-uniform fitting of the valve in the saddle; excessive wear of the guide sleeve also leads to increased flow oils, an increase in the volume of harmful emissions, which increases the risk of damage to the saddle);
• mechanical damage (contact with a piston or other component of the valve mechanism; too large valve spring force force; strong wear of the guide sleeve);
• balance of the valve end (incorrect adjustment of the valve mechanism as a result of the installation of worn superstars and other components);
• nagar on the valve head (too early ignition, oil entering the combustion chamber).

Over time, in the process of operation, the valve material is generated, as a result, the geometric shape of the part changes, which leads to various violations normal work valve mechanism. The consequences of minor wear are eliminated by grinding the valve. Strongly worn item is replaced.

When inspecting the springs of the valves, the following parameters are checked:

• deviation from perpendicularity (should not exceed 1.0 mm per 25, 4 mm. Spring lengths);
• the maximum deviation of the free length of the springs in the set (should not exceed 1.5 mm).

Valve springs should not have damage, corrosion traces, cliff or general signs wear. The surface ends of the spring indicate work with vibration or rotation as a result of its low length or insufficient stiffness. Such a spring should be replaced.

The most frequent defects of the valve saddles are the deviation from the magnitudes of the angles and the width of the edges determined by the manufacturer. From these parameters, first of all, the angle of landing, the area of \u200b\u200bcontact and, ultimately, the density of the adjustment of the valve head is dependent. The valve guide bushing directly affects the accuracy of landing the valve head in the saddle.

The prerequisite for the effective operation of the valve system is to ensure the concentricity (alone) of the four elements - the heads and the rod valve, the saddle and the guide sleeve.

Defects of the camshaft

Malfunctions of the camshaft (most likely reasons):

1. Nagar on the cam and rocker cam (Too strong heating of parts as a result of insufficient oil supply or blocking oil channels).
2. Strong wear cam (polluted butter, too small pusher gap or too strong plug-in valve spring force).
3. Premature wear of one or more cams and pushers, concave contact surface, damaged edges (inconsistency of the geometry of the contact surface of the cam and the pusher, for example, due to the installation of new pushers with "old" switchgear (or vice versa), as well as insufficient lubrication due to blocking channels or reduced oil pressure.
4. Cutting the camshaft (Deformation of the camshaft or cylinder head, including as a result of an incorrect sequence or exceeding the allowable torque of the fastening bolts).
5. Coupler fis (Exceeding the load as a result of the piston jam, the piston contact with the valve; insufficient clamp of the camshaft; weak valve spring, too high load of hydrocompensators, incorrect installation of a valve cap, breaking the gas distribution mechanism, incorrectly adjusting the valve mechanism).
6. Blue painting camshaft camshafts, bearings and rocker (engine overheating).
7. Occasions on the surface of cams, bearings and pushers (Too high axial movement as a result of wear wear, incorrectly installed phases of gas distribution).
8. Mechanical damage to the camshaft bearings (Solid particles in the engine lubrication system).

Defects of hydrocompensators

The most common "disease" of hydrocompensers is an excessive tension that can lead to a piston and valve contact. The reason for the defect, as a rule, is fatigue or breaking the springs of the valve or clogging safety valve Mud particles that are in machine oil.

In most cases, the hydrocomathers do not require replacement, it is necessary to set them strictly to the places from which they were dismantled. When examining hydrocomathers, it should be verified in the absence of damage (in the case of using movable hydrocompensators). If necessary, it is necessary to carry out the mechanical processing of the reference surface of the compensator without disturbing its hardness. Then it is necessary to clean the items thoroughly, collect and check the hardness of the hydrocompatator based on the manufacturer's data. In the absence of such data, the plunger return time can be considered at the starting point after compression by 3.0 mm in the range of 10-60 s.

Selection of gasket GBC

In conclusion, a few words about choosing a cylinder head laying. At first glance, a simple question is of particular importance when a noticeable change in the degree of compression occurred as a result of mechanical processing of the CCC. If you leave everything, as it was, that is, put the old gasket or the same new one, it may disrupt the normal combustion process in the cylinders, which means deteriorate the traction and power characteristics of the engine, will increase the content harmful substances In the exhaust gases. To restore the initial compression size, you can use a thicker gasket of the cylinder head or washer, however, there are gaskets not for all types of engines and only a certain thickness range. Therefore, make sure that the desired laying is better before making a decision on machining.

The required thickness of the gasket or the washers is easy to calculate, knowing the size of the GBC before processing and after it. If the engine is installed "recessed" valves (for example, as on car Peugeot. Xud7), it is necessary to take into account the volume of the protrusion of the valve and in the directory to find the corresponding value of the thickness of the cylinder head laying.

Valve tightness check - an important event, because from the density of the fitness of intake and exhaust valves The saddles depends largely. Today you will find out how to check the tightness of the valves, as well as how to Launch Valves at home with help special probe and set of auxiliary devices.

Without the correct and coordinated operation of the timing (gas distribution mechanism) - uninterrupted engine operation is impossible, it must be understood and timely identify all the problems in the work of this system. The key role in the timing is played valve intake and graduation, as already understandable from the title, some are released, and others are admitted ... Valve adjustment density - important momentfrom which, as mentioned above, it all depends on a very much of the combustion chamber the necessary pressure and work in the DVS. It will be ineffective, and possibly impossible at all.

In order to perform valve tightness check, you must have:

1. A wide plumbing line or a special pattern;
2. Priobrh paste;
3. Kerosene;
4. Special "fit" for ticking valves.

How to check the tightness of the valves?

Checking the tightness of the valve and the saddle is performed as follows:

1. The head of the cylinder block is removed (GBC).

2. Cleaning the GBC and the bearing housing from dirt, nagar and other oil sediments.

4. After viewing the working surfaces of the bearing housing, the camshaft supports, as well as the walls of the seating holes of the hydrotherapists, there should not be any traces of the influx of metal or scores.

5. The guides of the valves and the saddle should sit tightly and lay down to the "body" of the GBC. On saddles and valves there should be no cracks or traces of exercise.

6. Using the template, perform checking the planes of the GBC, In the absence of such this can be done with a wide metal line. Attach the line to the bottom of the head of the head diagonally, check if there is no gap between the GBC and the rib of the line. As a rule, it can be seen in the central part or at the edges. Measure the gap on both sides using flat probe, the maximum allowable gap is 0.1 mm. If you have more, it takes a milling plane milling or its full replacement.

7. Next is necessary check the tightness of the GBC.. To perform such a check, it is necessary to drown out on the end surface of the block of the feed window to the thermostat. Next turn the head and pour kerosene into its cooling shirt. Make sure that there is no subteps anywhere, in case of detection, you should repair the head of the cylinder block or completely replace it.

8. Now it came to the valve queue. To check the tightness of the valve GBC Put it on the smooth table with a busty plane to the top, then pour kerosene head in the combustion chambers and wait a couple of minutes. This procedure is also called the "spray". If you have noticed that the level of kerosene in the combustion chamber began to decline, or a puddle appeared on the table, this means that in this chamber one of the valves or both valves have a leakage, which means that the valve trigger is necessary.

How to eliminate the leakage of the valves? Valve catch

1. Eliminating valve leaks is performed by ticking them to saddles, in the absence of cracks or damage on a plate and valve, it can be restored by taking. To perform this procedure it is necessary:

2. Remove with the valve an oil clip cap.

3. Remove the valve that is poorly adjacent from the guide bushing.

5. The valve is installed in the head of the cylinder block, and attached to its rod "Advanced" for ticking valves.

6. Cressing the valve to the saddle, the trigger is performed by rotating the valve from the side to the side by making 10-15 such movements turn it to 90 ° and continue the latch again. Figure should be performed until a uniform smooth surface is formed on the plate and the saddle, and the parts themselves will not be perfectly seamless to each other.

7. Upon completion of the remnants of the prior paste, and the valve with new outlooking caps Installed in place.

I have everything, I wish good luck in your work! Thank you for reading us to new meetings!

Deformation of the key elements of the engine, such as the cylinder block and the head of the cylinder block, are serious faults that when untimely elimination can lead to necessity overhaul Motor. The formation of cracks in the engine cylinder block and the head of the cylinder block is one of the most complex breakdowns in the car. There may be cracks due to impact (for example, with an accident), due to high wear or production marriage. Within the framework of this article, we consider how to determine what has cracked the engine cylinder block or CCC, and what can be done with it.

Table of contents:

Symptoms of the formation of cracks in the cylinder block and cylinder head

There are several signs, when the discovery is discovered to beat the alarm and send the engine to the diagnosis. They may indicate both the formation of cracks in the engine and on other malfunctions. Most often about cracks in the cylinder and Cylinder block indicates:

• Regular. If due to the crack, the system has ceased to be hermetic, this will lead to the flow of coolant and constant overheating of the engine. Also, such a problem may arise due to the projection or other defects;
• Problems with the operation of the device for controlling the temperature (thermocouples). This is fraught with strong engine overheating and its deformation;
• IN expansion tank Pressure does not hold and air traffic jams are formed;
• Incorrect indicators. If the temperature sensor arrow changes chaotically, then in large, then in a smaller side, it may indicate a sharp jumps of the temperature of the engine itself during operation;
• Engine vibration. One of the most obvious signs of cracking in the cylinder block. If the engine is overly vibrated or "Troit", especially when driving in a hill, it may indicate the presence of microcracks in the engine block.

How to detect cracks in the cylinder block

Not always, when it comes to a crack in the cylinder block, it is understood by a seriously noticeable eye defect. Quite often, these are microcracks that can be defined by one of the following methods:

• Pneumatic crimping;
• Use of ultrasound scanning;
• Applications of specialized magnets-sensitive equipment;
• Hydrocontrol.

Each of these methods allows you to establish whether microcracks are in the cylinder block, and where they are specifically located. Most often in service centers in the absence of specialized equipment for diagnosing the cylinder block use a crack search method with water or air.

The essence of this method is simple - water is injected into the cylinder block, and if it seeps, it means that there is a crack in this place. When using air, air is injected into the air, and the part itself is immersed under water, thereby you can understand the presence of bubbles on the water surface whether there is a crack.

Please note: To accurately determine the cracked place, you can use magnets. They are installed at the edges from the intended split of the cylinder block, after which the space between them falls asleep with conductive sawdust. If the crack is available, the magnetic field line will tear, and the sawdust will be assembled in a place where the microcrack is located.

How to close the crack in the cylinder block

Depending on the scale of damage, you can use various methods Repair block of cylinders. It is worth noting that in some cases it is more expedient to replace the block, and not its repair.

By welding

The most common way to close the crack in the cylinder block. At the same time, the welding of the block of cylinders is quite difficult work, since it implies a clear observance of the technological regulation. If you make errors when welding, during the operation of the seam engine will be dispersed and the problem will return.

When welding initially, the ends of the crack on the cylinder block occurs. It must be done to avoid the probability of crack propagation. Putting and further grinding is carried out at an angle of 90 degrees.

Next, the welding process begins. To do this, the cylinder block must be heatled up to 650 degrees Celsius, after which it is superfluous with a twisted cast-iron-copper rod and a flux. Next, the part is gradually cooled into the thermoshkafu.

Important: It is impossible to sharply cool the item, otherwise it will lead to the seam rupture.

It is worth noting that you can perform welding of the cylinder block without warming it. To do this, use electric welding and copper electrodes in a tin wrapper. At the end of the work, the imposed seams must be deguted with acetone or special compositions. On on top of the seam, you need to apply a layer of epoxy paste with a spatula. Next, the part needs to be "dried", leaving it at room temperature for 24 hours so that epoxide is completely dry. The final stage is grinding the processed seam.

Applying Epoxide and Fiberglass

A simple method that allows you to eliminate minor cracks on the surface of the cylinder block. The method implies the creation of an additional layer on the surface of the crack, made of epoxy paste and fiberglass.

To close the crack in this method, it is advantageous to deflect the surface well so that the superimposed compositions are better to "fit." Next, several layers of epoxy paste and several layers of fiberglass are alternately superimposed. The last layer must be epoxide.

SEAL-LOCK method

A rather time-consuming modern way to eliminate cracks of the cylinder block. Its explicit advantage is the ability to carry out work without welding and without dismantling the engine itself. The essence of the method is to fill the existing cracks with soft metal.

Work is performed as follows:

In contrast to the method of repair by welding seam, the SEAL-LOCK method allows to obtain a more reliable seam that is not susceptible to the temperature differences.

The crack in the GBC occurs as a result of the improper operation of the engine due to overheating and stress shift in the metal.

Symptoms of cracks in the head of the cylinder block

Cracks can appear in different places, from here and different consequences. It basically the opinion that when the head is broken from exhaust pipe It goes white smoke, but this is only one particular case. The crack in the head may occur between different channels, respectively and the signs of the presence of a crack in the CCC will be different.

Oil system- When mixing oil and toosol in the engine, an emulsion appears instead of oil, a white foam, like a biscuit dough, and an oil film is formed in an expansion tank of the cooling system.

Intake canal- If the coolant begins to fall into it, first of all it will wash the pistons to the brilliance, you can look through the candle hole, the pistons will be like new ones. And when hitting the combustion chamber, it is just the case when it can go white smoke from the exhaust pipe, although not the fact that he will go.

With channel release- Here the coolant will simply fly into the tube in the form of a couple. The engine constantly releases steam and notice anything in this case It is hardly possible, it will be easy to leave a tank liquid. Most likely, even the smell of exhaust gases will not be in the tank.

With combustion chamber- After a crack, part of the liquid will go to the combustion chamber, but a very small amount, everything is due to the pressure difference. In the engine when combustion of fuel, large pressure is formed, and exhaust gases through this very crack fall into the cooling system, increasing the pressure in it. Because of this, the nozzles are swelling, and the tank stinks with exhaust gases. But the liquid can also go to the chamber combustion system Cooling is still under pressure, and in the combustion chamber has already gone, the air began to suck. Due to the difference in pressure, the coolant begins to leak into the combustion chamber. A sign of such a crack will be pure pistons (not always), smell in the tank, elastic nozzles and a cold stove radiator (air stopper).

Typical Frame Education Places in GBC

Automakers Adjust the formation of cracks in the head, and this will not be considered a malfunction, since the crack will be shallow and it will not connect two tanks. In diesel engines VW, the head with a crack between the valves is allowed to use.

But finding all the cracks - the task is problematic even for an experienced motorist. It would seem that the same cracks should be formed in the same places in the same places. But this search is not simplified. There are places that can be found in one glance on the head:

—between valves- The crack is immediately visible, passes under the seats of two adjacent valves.

—between the candle and valve- The same situation, again, everything is in sight and nowhere should not look

—in diesel engine The crack can go from the valve towards the forcamera, such a crack is easy to notice, but how to see it if it is formed under the forkamera and does not come out?

—under the guide valve- Another golden place where the crack is not visible, firstly, in the channel and so dark, and secondly, the crack is covered with the guide bush. Here you need another approach, not just visual. And what is the benefit of detecting the crack between the valves, if gases do not break through it? We will not rely in case, the more diagnostic method is invented for a long time and has established itself from the best side.

Checking the CFC to crack

To check the GBC into cracks, it must be placed, that is, hermetically close all the holes, and blow air into the canals. If you drop the head into the water, bubbles will go out of the crack. Or, on the contrary, to drown all the holes and pour the water into the channel, after which they pump the air to the pump, creating a pressure of 0.6-0.7 mp, and give to stand so the head 1 \u003d 2 hours. If water leaves, then the head is broken.

There are still dyes that type water. They are very clearly visible on the crack.

And the holes are closed in the cooling shirt very easily: to nicknamed rubber gasketwhich is slightly larger than the hole, the metal plate is superimposed on top, which is screwed by a bolt to the head. And no water will pass. And to the stacker, which will perform from the head, connect the pump and pumped up the air. Such crimping allows you to identify all cracks.

Repair of cracks

It is high-quality to close the crack only with the help of welding. No adhesive composition will be able to high qualityly close the crack in the head, because when heated to operating temperatures, the head will expand and the crack will become greater, that is, it is necessary to make a crack to close the crack, which would have the same linear temperature expansions, as well as the head material, to The same to be resistant to other loads. All this is possible to achieve only welding.

Preparation of the head for welding

Before welding the crack, it is necessary to separate, for this, the milling machine drill the metal along the entire length of the crack. The groove should turn out to be quite deep, 6-8 mm deep and about the same in width, in form it is desirable to make a wedge-shaped one. It will help better slaughter metal. For the cutting of the crack between the village, you first need, but only then partition the crack.

After cutting the cracks, the head must be heated to a temperature of 200-250 ° C, but not higher, so that the head does not lead. Heating reduces the voltage in the metal arising during welding. To heate it, it is best to use acetylene burner or a furnace, but you cannot use a soldering lamp, because it can be easily overlayed with a cylinder head.

Welding GBC.

To weld the head of the cylinder block, you can use gas welding using an additive material, but top scores Gives argon-arc welding (TIG). A mass is connected to the head, and the arc is on the argon medium between the tungsten electrode and the head where the aluminum additive wire is applied.

After welding, the seam must be cleaned, repeatedly press, and if everything is fine, the surface adjacent to the block, die to be perfectly smooth.