When heated, the valve clearance increases or decreases. From what is the increase in the valve clearance. The consequences of incorrect thermal gaps of valves. Causes and consequences of the knock. Too big gap

Simple views, engine valves internal combustion Perform in it crucial work: Control the fuel mixture of the fuel mixture and the output of the exhaust gases from the engine cylinder. From how timely this processes will occur, the efficiency of the engine operation depends: its power, efficiency, toxicity, and even the opportunity to work itself.

How should the DVS valves work

The operating cycle of the four-stroke engine consists of four strokes: inlet, compression, work move and release. Based on the purpose of these clocks, it can be understood how the gas distribution mechanism should work: the intake valve opened on the intake tact, opening access of the fuel and air mixture into the cylinder; On the compression tact, both valves are closed (otherwise you do not exist); During the work stroke, the valves are also closed so that all the extension energy of the burning mixture is directed only to the movement of the piston; During the release of the exhaust valve, the spent gases are opened through it together the cylinder.

Exactly so it would be if the valves had the opportunity to open and close instantly while the piston is in its dead point, top or bottom. To submit that a moment for a period of time during which the engine operating cycle occurs, we must recall that modern engines easily reach six and more than thousands of crankshaft revolutions per minute. In one working cycle, the crankshaft performs two turns, it means that each of the valves opens and closes three thousand times in a minute. And the piston turns out to be six thousand times in his dead dots! For comparison, the rapidity of the legendary Kalashnikov machine gun is only six hundred shots per minute, exactly ten times less! In such conditions, even several milliseconds of the engine are worthy of the time period, during which very important processes occur during.

In theory, both valves are closed during the compression stroke and working stroke. Figure: I - inlet stroke, intake valve open; II - compression stroke; III - work move; IV - release course, exhaust valve open

And even if modern valves are able to move much faster than their ancestors a hundred years ago, the properties of combustible gases, the movement of which they manage, have practically not changed. They are also easily compressed when exposed, and also stubbornly continue to strive in all directions in the same way, obeying the law of Pascal, which means they are not very rushing to move where they are asked. And in order to ensure the maximum possible filling of the cylinder in such a short period of time, the intake valve begins to open earlier than the piston will complete the release course. And the graduation will begin to open earlier than the work movement will be completed so that hot gases are under pressure in the cylinder did not create excessive resistance to the movement of the piston when the release tact will begin.

Moments of time when the discovery begins, the duration of their location in the open and closed states, form the gas timing phases. Controls the movement of valve camshafts, in the form of fists of which and "encrypted" information about the phases of the gas distribution of your engine. The values \u200b\u200bof the phases are selected when designing the engine, depending on its design, destination, operating conditions. In the most advanced engines, these phases may vary for specific working conditions and loads at the moment. In the usual motors, the only effective way to change the gas distribution phases is to replace the camshaft. Changing the phases of gas distribution by means of installing the original camshaft is one of the ways of advanced engine tuning. Agreeing to such a procedure, we must understand that the growth of engine power will occur due to deterioration of the cost-effectiveness, reducing the resource of its parts. Therefore, such a setting is usually used on sports carsWhere the resource, the efficiency and environmental friendliness of the engine is of a secondary value.

IN real EngineWhen the piston is located near its top (NTC) and the bottom (NMT) of dead points, intake and exhaust valves are at the same time open

Where to install camshaft

Exist different variants The arrangement of the camshaft in the engine and the design of the mechanisms transmitting pressure from the surface of the camshaft to the valve rod. However, the growth rate of modern passenger engines He led to the fact that the scheme was consistent with the arrangement of the camshaft in the engine head - the upper structure. The proximity of the camshaft location to the valves allows you to increase the rigidity of the system, and therefore improve the accuracy of work.

The prototype of the first "Zhiguli" VAZ-2101, the Italian Fiat-124, had a good and reliable, but the incompected engine design with the lower camshaft. Soviet engineers decided that the engine of our new car should keep up with the times, and together with the Italians modernized him, moving camshaft into the head of the block.

Why need clearances

A valve is closed under the action of a special spring. In order for the cam profile by no circumstances to prevent the full closing of the valve, a strictly defined clearance is set between it and the pusher. Moreover, this gap should also take into account the increase in the rod length when heated. And the valve heats up during operation can be very strong.

The head of the inlet valve of the automotive engine is heated to a temperature of 300-400 degrees Celsius. And the graduation, which is "washed" with hotly spent gases - up to 700-900 degrees, becoming dark-cherry color.

Ways to provide heat gap

Under the upropment circuit, the camshaft affects the valve terminal or directly or through the rocker. The use of a rocker allows you to reduce the camshaft profile difference relative to the maximum valve movement when opening. With the direct effect of camshaft on the valve rod, the rod perceives significant lateral strength, which leads to increased wear. To avoid this, the end of the rod is covered with a special glass that takes over the lateral force, moving in its own guide socket, and transmits axial power to the valve. Between the glass and camshaft cam are installed adjusting washers. If the design has a rocker, they set special adjusting screws with lock nuts.

Many modern engines, especially having more than two valves on the cylinder, are equipped with hydraulic gap compensators in valves. In these structures, heat gaps are not required.

Valve adjustment: when and how

As a rule, the clearance is checked and regulated at each. The procedure is performed on a cold engine. To perform work, you will need probe and ordinary hand tools, depending on the fastener applied on your car. For valves with adjusting washers, tweezers are also useful, be sure to read the guide to repair your car, where the size of the gap, the features of the engine design are indicated and the sequence of its disassembly and assembly is described. In general, the procedure for execution of work is as follows:

• remove valve cover;
• lay the labels on the engine block and crankshaft shaft (usually on the pulley of the timing belt);
• turning the crankshaft using a suitable key (but in no case is not a starter!) In a clockwise direction, if you look from the front of the engine, align the labels with each other. In this position, the piston of the first cylinder is located in the upper dead point, both valves are closed;
• check the gap between the first - from the side of the pulley - camshaft cam and adjusting washer (fivest bolk);
• if the size of the gap is more required, it is necessary to replace the washer to another, greater thickness; If the gap is less, then, accordingly, the thickness of the washer should be reduced. The nominal thickness of the washer is usually marked on it itself. If the thickness of the washer is unknown, then you will need a micrometer for right choice New washer. In constructs with a rocker, the procedure is simpler, since we achieve the required gap, turning or turning the adjusting screw. After adjusting the screw, do not forget to tighten the lock nut.
• After adjusting the clearance check, you must repeat. Allowable deviation: plus-minus 0.05 mm.
• Pay attention to the fact that the size of the gap for the intake and exhaust valve is usually different. This is associated with different heating temperature, as stated above. So, for the eight-glove engine VAZ, the gap on the inlet valve is 0.20 mm, and on the graduation - 0.35 mm.
• Work repeat for all cylinders by defining their sequence and angle of rotation of the crankshaft in accordance with the recommendations of the engine manufacturer.

Video: How to adjust the gaps on the front-wheel drive freight

In general terms, the design of the gas distribution mechanism and the procedure for adjusting the gap in the valves on diesel engine The same as on gasoline.

It is believed that after installation on the engine of gas-blade equipment, it is necessary to change in the direction of increasing the thermal gap in the valves. Explain it more high temperatures Gas burning. In fact, this is not required. Features of ignition and combustion of the gas mixture in the cylinder are accounted for by changing the ignition angle, and the filling and removal process from the cylinder does not differ from that when the engine is operational on gasoline.

When the gap is not only visible, but also heard

Often the gaps in the valves are heard, especially in cold weather. This is expressed in light metal skiding when the impenetrable engine is working. As he warmed the sound weakens. If he is heard and on the heated engine, then, most likely, all or some of the gaps are more than the norm. The increased thermal gap reduces the time of finding the valve in the open state, which reduces the efficiency of the engine, it begins to work with interruptions, it is badly started, the occurrence of detonation combustion, which is pernicably acting on the engine parts. Even more dangerous reduced gap, because it completely disappears in heated to operating temperature Engine and valve stops closing to the end. As a result, the power and economic indicators of the engine are also reduced, but the most unpleasant when the conical chamfer on the valves and on their sidls are burning, and this problem is simple to adjust the clearance.

The engine is the heart of the car, so any signs of deterioration of his work should make you alert and, at the first convenient case, it is diagnosed. If the power dropped, the fuel consumption increased, if the engine "Troit" or is heard cotton in exhaust system - Check out the health of the spark plugs and check the gaps in the valves.

On the engines of many modern cars, the adjustment of valve gaps is not needed due to hydrocomathers. If there are no such, the manufacturer necessarily indicates the exact dimensions of the gaps of the engine valves in the repair manual, the non-compliance with which leads:

• to reduce engine power;
• unstable its work at idle;
• increased fuel consumption;
• premature wear and failure of the GDM and some other details (consider later).

Valve gap measurement

When the engine is running, the Detail of the gas distribution mechanism is very heated. Because of this, a linear increase in their size occurs. Therefore, when assembling it is important to observe the thermal clearance of valves, which compensate for such an increase. This will prevent elevated friction between the details. But increased valve gaps do not allow the drive mechanism (which includes camshaft, rocker, pushers, etc.) open them to the desired value. Consider what it leads to.

Insufficient open intake valve will prevent the filling of the combustion chamber fuel mixturethat will adversely affect the power of the motor.
The graduation in such a situation will prevent the removal of combustion products, which is why the Nagar appears on the details, which will be deposited on:

• the bottom of the piston and the surface of the combustion chamber, worsening the heat sink and thereby contribute to overheating of the parts;
• the spark plug of the gasoline engine or the glowing candle of diesel, which due to this fail prematurely;
• the working surface (chamfer) of the valve and its saddle, which will prevent their tight fit to each other and will cause a decrease in compression in the cylinder.

In addition, large valve gaps increase the impact load of interacting parts and can provoke:

• the top of the top ends of the valves;
• deformation came to
• breakdown springs;
• damage to the pushers;
• breakdown rumor.

On the engine running, excessive gaps give themselves a ringing characteristic.

The reduced gaps of the engine valves can prevent the tight fit of the latter to the siders, due to the fact that the valve "lengthened" from heating will be pressed from the saddle with the pusher. In this case, a significantly overheated edge of the graduation can burn. In addition, compression is naturally reduced.

Clearance between valve and guide sleeve

Excessive increase in the diameter of the opening of the guide sleeve due to wear leads to the fact that the pair of the sleeve is starting to work like vacuum pump, "Pumping out" oil from under the valve cover into the combustion chamber. About what the formation of Nagara leads, we have already spoken. Another unpleasant consequence of the wear of the sleeve will be oil consumption.

Measurement and adjustment

Adjusting valve gaps

A detailed description of these procedures will take volume with a brochure, as they would pass into technical terminology and the details of the timing of the timing of various structures would have had to go into technical terminology.
Basic and necessary rules concerning all OVS without exception:

• the measurement and adjustment of valve gaps should be performed only on a cold engine;
• these actions should be carried out only when the valve is closed, for which it is necessary to know the order of operation of the cylinders and the location of the installation labels on the stars (gears) of the camshaft (or camshafts) and crankshaft;
• tags on the stars and gears need to be accurately combined with labels on the engine housing, turning the crankshaft along the rotation. For two turns of the crankshaft camshaft makes one turn.

The simplest measuring instrument is the probe to adjust the valves. For classic "Zhiguli", for example, it is sold separately (0.15 mm), but on some motors not all valves have the same amount of gaps (for example, on ZMZ-402) and a set of probes is necessary. Using the micrometer, you will achieve greater accuracy, but it is necessary to use it together with the gap measurement device.

Special tools are used to adjust the valves

For the same "Zhiguli" it is a rail that is installed on the stiletto fastening "bed" camshaft. It indicates the angles of rotation corresponding to the closed position of one or another valve.

In addition to measuring instruments, sometimes needed devices for adjusting valve gaps.
For example, on the engines of the VAZ 2108 family, this is a set of two tools. One valve pusher ("glass") is pressed from the camshaft fist, another position of the pusher is fixed, which allows you to replace the adjusting washer.

In any case, if you decide to adjust yourself, auto parts stores will not leave you with bare hands.
Read more about the adjustment of valve gaps (on the example of cars VAZ), see the video on our website!

Internal combustion engines that are installed on modern carsThese are quite complex mechanisms with many details. Therefore, for normal operation for a long time, they require proper maintenance.

Unfortunately, many motorists do not pay due attention. For example, they do not understand very well, for which the valve adjustment is needed and often ignore this procedure, which leads to additional breakdowns and large costs for repairs. In this material, we will discuss what the valve adjustment is, which engines it is needed and how it is performed.

Before answering the question of what valve adjustment is, you must first find out what is the valves of internal combustion engines, where they are located, and the performance of what functions is assigned to them. Structurally, these important details modern engines Present "plates" of a cylindrical shape with sufficiently long rods. They are installed in the cylinder block, and in the amount of at least two for each of them. The valves in the closed state are adjacent to the saddles, which are made of steel and are compressed in the head of the cylinder block (GBC). Since these parts are experiencing significant mechanical and thermal loads in the process, they are made from special, resistant to these sodes steels.

Valves are component parts Gas distribution mechanisms of cars (MRM), which are often called valve. They are divided into intake and graduation. The function of the first is, as it is not difficult to guess through the very name, the inlet of the combustible mixture into the cylinders, and the second is the release of the exhaust gases. In the process of engine operation, the valves are expanded, their rods are lengthened, respectively, the size of the gaps, which should be between their ends and pushing cams (in the engines of old designs - rocker). During the operation of the FEA, the dimensions of these deviations increase, and precisely when they begin to exceed the maximum valid values, the valves should be adjusted. It is to bring the gaps to normal.

If the valves are not periodically adjusted, it can lead to very ugly consequences. In the case when the clearance is too small, "burning will inevitably happen. This means that on the surfaces of the valves will form a sufficiently dense layer of products of combustion of the fuel mixture. Because of it, the normal operation of the gas distribution system is disturbed, and, consequently, the engine as a whole. In addition, this tagar is quite difficult to remove.

In cases where the clearance is overly large, the valves are not fully open, and therefore the engine power drops significantly. In addition, they begin to "knock", and this knock has experienced drivers hearing, even being in the cabin, driving their cars. It goes without saying that increased valve gaps affect the operation of the internal combustion engine is no less negative than the excessively small.

What motors and when valve adjustment is needed?

It should be noted that not all internal combustion engines require periodic valve adjustments. The fact is that now in many modern ICS, which are equipped with carsIn the systems of their gas distribution mechanisms, the following types of hydrocomathers are established. These devices independently regulate the gaps in real time, and therefore their value is always optimal.

If in the engine vehicle There are no hydrocompensators, then adjust the valve is manually necessary. It's time to come to deal with this case, it is quite easy to learn about some symptoms. One of them is the characteristic "Casting" of the valves, which has already been mentioned above, and the other is that the engine begins to "Troy", in its cylinders or significantly falls, or completely disappears compression. As soon as one of these symptoms manifests itself, it is necessary to check the size of the gaps in the valve mechanism.

It is also necessary to do this and without waiting for "disturbing bells", as part of activities on the current maintenance of the car. The frequency of checking valve gaps is indicated in technical documentation On each vehicle, and, as a rule, is once every 25,000 - 30,000 mileage kilometers. It is usually carried out at stations maintenanceBut, possessing certain skills, checking valve gaps can be carried out independently.

Valve adjustment procedure

Valve adjustment is necessary only on a cold engine, and with strict observance of a certain sequence of actions. Otherwise, the gaps will be adjusted incorrectly with all the consequences of this.

The adjustment process begins with the fact that the cylinder piston is installed in the upper compression point. To bring it into such a position, you need to check the crankshaft or for the starting handle, or for the screw for fastening the pulley of the generator drive. It should be noted that the rotation must be performed only clockwise. After the piston is installed, it is necessary to check the size of the gap. This is done using a special probe.

If it turns out that the gap or is overly large, or too small, then it is necessary to change it. To do this, on the appropriate bolt or screw, you must first release the lock nut, and then set the gap to the limit required. It is determined by the thickness of the appropriate probe. As soon as the gap value is installed, you need to fix this position by tightening the locknut. It is necessary to do it carefully and carefully not to knock down the setting. After that, it is necessary to check the correctness of the valve adjustment using the probe: it should be included in the gap, but not free, but with some effort. If so, it means that adjusting the specific valve of a particular cylinder is made correctly, and you need to do all the procedure described above for all remaining valves and cylinders.

Sooner or later, car owners are faced with outsiders on idling. Many pages are written about how to diagnose noise data. One of the reasons for these sounds can be disturbed gaps of the engine valves. Let's see how to adjust the valves, how to change them and repair.

What are valves, their role in the work of the engine

Experienced motorists can skip this part, and for beginners will be useful this information. In order for the motor to work, two valves for each cylinder are needed. Now they apply to the carbed, with rods. In order for cylinders to be better filled with fuel mixture, the diameter of the plate at the inlet valve is greater than that of the graduation. Cast iron is used as materials for the valve seat or steel. The saddle is pressed into the GBC.

When the engine works, these parts are susceptible to serious loads. That is why they are made of heat-resistant and mechanical loads of alloys.

Principle of operation of valve

Before talking about how the valve clearances are regulated, we will understand in principle their work. Any car enthusiast knows that the main task of these nodes is an inlet and release. So in engines carried out gas exchange.

Initially, a mixture of fuel and air flows through the intake valves, then the combustion products come out through the exhaust valve. The opening and closing of the valves occurs under the influence of the camshaft camshafts. To the valve can return to its rightful place, the spring helps him. Also, this spring plays another very important role. When the valve is closed, it contributes to the most dense and hermetic fit of the plate to the opening into the CCC or Sader. This ensures the tightness of the system.

The need for gaps

Valves consist of a rod and so-called plate. When the motor heats up, the part rod becomes longer. That is why, in order to compensate for such an elongation, manufacturers have provided valve clearances between the rod and camshaft camshaft. And if more precisely, there are valve and cam rockers.

This gap is only on a cold engine. And when the engine is quite warming up, then they decrease or completely disappear, since the valve rod lengthenment is leaving due to heating. Therefore, these gaps and got such a name are thermal.

Where does noise?

When the gap grows, the cam hits the rocker, and the driver will hear characteristic noises. These valve gaps must fully comply with the recommendations of the car manufacturer. And the noise is only a small part of the numerous side effects of incorrect gaps. If the valves wear out, then the rocker is wearing directly, and then the camshaft camshafts. So, the cam will beat the rocker, and not smoothly press it. Any car owner should know how to adjust the valve.

When the clearance is too big

When returning the valve into the usual position of the camshaft camshaft (if the gaps are increased), it is too early from rocker. At this point, the valve is not closed yet. Here the spring is no longer held by anything. Therefore, she with a serious effort throws a plate in the saddle on the GBC.

Here you need checking and adjusting valve gaps. These strikes occur constantly, as a result of which fatigue, microcracks, voltage are formed on the valve plate and on the saddle. If you go further on such a car, then a dish of a plate may occur. And this can already entail serious problems.

If the clearance is less than the required

In this case, another problem may happen. This overheating is either the extension of the valves. Basically, the problem concerns the graduation group. Our valve opens ahead of time, and closes a little later. Therefore, the period is reduced when the plate is in contact with the saddle and can cool. If there are no thermal gaps, the valve may not close completely. As a result - overheating, burning, cracks, molten edges of the plate.

Valve Protection Hydrocompon

On most modern motors there are these devices. They protect the valves from any problems. Here the thermal gaps of the valves are compensated by changing the length of the compensator to the value that is equal to the gap.

But not all engines costs this device. Therefore, those who have no hydrocompensator, you need to regulate the gaps manually.

Why do you need to adjust the gaps?

All because in the process of engine operation, the thermal gap gradually increases. Also adjust these mechanisms is necessary after repair.

Now we know what the correct gaps are affected, and why and when it is necessary to carry out work. Therefore, you can start learning to customize the gaps.

It must be said that the adjustment of valve gaps will not give any increment of power. However, thanks to the correct gaps, the engine will operate in normal mode, and you will not need to change the valve mechanism or the entire piston group. After adjustments, the motor will simply work better. If everything is completely bad, it is possible to add a lost previous power.

Adjust valves on VAZ cars

So, if the valves suddenly littered, it means to configure them. To do this, you should not go to a hundred, all work can be done by yourself, with your own hands. To do this, you just need to know the procedure and valve clearance. VAZ has definitely different data adjustment of the mechanisms. For the inlet valve, the clearance should be 0.2 mm, and for the graduation - 0.35 mm.

If you manage to spend these works yourself, then you can save 1000 rubles.

To adjust the most efficient gas distribution on the VAZ, we will need to remove the valve lid. Then prepare the probes of the necessary thicknesses, the horn keys on 13 and 17, also need a fair portion of patience.

In order for the adjustment of the valve gaps perfect, you need to know what a sequence of phases of gas distribution, as well as a sequence of adjustment of the account.

First, check the crankshaft until the labels on the star and the housing coincide. We are the first to regulate the 6th and 8th valves. Further check the crankshaft clockwise 180 degrees. Now you need to regulate the 4th and 7th. Another turn, and the 1st and 3rd valves, and then the 5th and 2nd.

Clearance adjustment procedure

Everything is simple here. In the gap, which was formed between the lever and the cam, insert the dipstick. What kind of gaps on the valves of your engine can be found in technical document. If the dipstick passed with a slight force, then no action is required.

If the dipstick did not pass or passes, but it is too loose, then it is necessary to release the tunnel bolt's wrench. It will verify the desired angle.

And how on foreign cars?

Here is still the same. At first, we remove the cover, then get access to the gas distribution system. Gaskets, as well as seals need to be replaced after the work done, otherwise you can face oil leaks.

To successfully perform work, you will need some tools. This is a set of probe providing the 2nd grade of accuracy. With their help will be checked. Next, we need a bent horn key or a ratchet with a head for 10. In the case of foreign cars, an ordinary horn key will not help.

How to adjust the valve?

It is worth saying that each valve is adjusted separately. In the case of 4-cylinder engines we have 16 valves. The valve groups of each individual cylinder are also configured separately.

Start always follows from the first cylinder. You need to adjust it, and then go to 3, 4 and 2nd. The order is exactly the case, because it is just convenient. It is only enough to set each piston to the upper dead point.

Before adjusting the cylinders are installed in the NMT position. In this position, the valves are free and closed. This procedure must be carried out for each of the cylinders. For this pulley distributional shafts Have labels. They allow you to set each of the pistons. For these tags and gaps are exhibited.

So, the 1st cylinder. If you know the size of the gaps in a particular engine, then you need to fold the probes under the desired size. Next, insert the probe between the camshaft camshal and the rocker of that valve you want to adjust. In our case, this is the first valve.

Next, loosen the lock nut, and then tighten the screw to the adjustment and move the probe that should be in the gap. It is necessary to twist it until it becomes resist. As soon as you felt that it slides in the gap with some resistance, tighten the lock nut. Check again, and then tighten completely.

For the rest of the cylinders, the action is exactly the same, just need to install each piston in the NMT position. This can be done by tags on the pulley.

Replacing valve

Sometimes it comes time to change worn nodes and parts. To replace the valves, you must use the special tool - the puller. The principle of replacement is completely the same for all VAZ models.

First of all, you need to remove the shaft of the timing distribution. Then - pushers and rocker. Next, you should consolidate the tool using the tree studs, and put some spacer under the valve plate. Now remove the crackers. It should be done everything neatly. The valve mechanism has very powerful and serious springs. If such a spring play, then these crackers will flee unknown where.

After removing the superstars, it is time to remove the plate and springs. Under the latter, you will also delete the plates. And they should be removed. First you need to remove the gland. Now you can pull out the valves. That's the whole operation. Replacing valves, too, as you can see, an easy task.

How often regulate valves?

In books write that the valve mechanisms are needed only after major repairs Or then when the GBC disassembled. It is not right. These details over time wear out quite naturally. The speed of this wear is also affected by the temperature and manner of riding a car. It is recommended to check the gaps of approximately 20-30 thousand km.

If you hold such an operation for the first time, then ask to observe your actions more experienced comrade in this plan. With timely adjustment, the repair of valves or their replacement you are not threatened.

The adjustment of valve gaps, due to the technical complexity of the process, is usually carried out by specialists in service centers or in specialized workshops, but if desired, you can independently carry out this procedure. However, before this is a hard thing to do this, we still, we strongly recommend carefully to study the principle of the mechanism, as well as see how a person does who has experience in conducting such works.

Principles of Engine Valves

The distribution and crankshaft of the engine between themselves is connected by means of a toothed, belt or chain transmission, with an optimal ratio of 2: 1. For one handover, the crankshaft distribution element carries out two turns. The shape of the camshaft camshaft is able to ensure the closure and opening of the valves so that they correspond to the position of the crankshaft, the engine cycling, as well as distribution phases.

In the process of operation of the engine, all parts are slightly increased in size due to light heating. As a result, the overall distance between the camshaft and the valve pusher. When the motor warms up to the optimal operating temperature, the pusher is tightly pressed to the valve and camshaft. Due to this, the most efficient operation of the engine is ensured.

If the end of the closed valve is fixed in the position above the pusher, a clearance that reduces the engine compression is formed between the saddle and the plate. If the end of a fully closed valve is below the pusher, during the corresponding gas distribution phase, it will open a little less than necessary. As a result, the power of the motor will be reduced, since the less the valve is open, the worse the air and exhaust gases will go through it.

Why are valve clearances

Answering the question why the engine clears are needed, it can be noted that for normal operation of the motor, the thermal gap is quite important. Due to it, the closing and opening time of the valves is observed, and the preservation of the optimal level of tightness in the closed state is ensured.

If the gaps are exhibited in accordance with the rules, after heating, their parameters are reduced to minimum indicators. Due to this, gas distribution phases and a long service life of parts are ensured.

During the operation of the car, the gap varies in a large or smaller side. Depending on such deviations, certain problems are manifested. In the bulk of cases, this leads to a decrease in the service life of the valves, to a decrease in the power level of the engine, it becomes worse than the cylinders of the fuel and air mixture, the overall combustion efficiency is reduced and so on. It is for this reason that it is so important from time to time to adjust the gaps.

Check and, if necessary, to adjust the gaps is required every 20 - 30 thousand kilometers. It is necessary to rely on the standards prescribed in the repair manual for a car of a particular brand.

How the desired gap is ensured

The desired gap can only be obtained through competently carried out adjustment. When implementing this process, the main gas distribution mechanism is set up, especially the gap, which is between camshaft camshaft and valve lever.

There is a special instruction regarding how to adjust. It is not enough to ensure a more dense pressing of valves, since with increasing temperature, all parts become greater in size. Such expansion automatically leads to different negative consequences.

Intake and exhaust valves should close the nest tightly, but at the same time with a small gap. It is necessary in order for the valve rod does not resist rigidly into the upper part of the device.

In the process of independent regulation of gaps, you need to strive for strictly established values. They should not be greater than 0.15 mm. The maximum level of permissible error is 0.05 mm. These parameters need to be checked exclusively with a cold motor.

Provided in the process of adjustment the correct gaps, the driver will receive the steady operation of the engine, considerable fuel savings, as well as an increase in the motor test.

Signs and consequences of the wrong gap

After starting the engine, he himself and all its details, begin to heat up significantly and automatically expand. It is also worth taking into account the natural wear of the elements in contact with each other. All this is the basis for ensuring strictly installed gaps between defined details. Deviations from the norm are able to lead to certain problems. Their list depends on which direction the gaps changed - in a large or smaller.

Too big gap

If the gap will be greater than the desired size, the driver will begin to hear the characteristic Motor Cocan, gradually leaving along with the warming of the car. With an enlarged gap, the camshaft fist does not pushing the rocker of the valve rod, and it starts just knocking on it.

Similar long-term shock load leads to such unpleasant consequences, as:

• significant decrease in valve life;
• digging;
• scholelt, which further increases the gap;
• increase the noise in the engine.

At the same time, the engine power decreases, due to a serious disruption of gas distribution processes.

Too small gap

With a very small gap car Engine It will not be able to fully realize its functionality. This will automatically affect the total speed and dynamic characteristics vehicle. At the same time, there will be significant overheating of all exhaust valves with melting their edges. Among the main consequences of a reduced clearance size, the following factors based on the loss of tightness of the combustion chamber can be noted:

1. Reduced compression, due to the emission of the fuel and air mixture.
2. When working, the spent and split gases break through and lead to a strong valve direct.
3. Plates cease to concern that it disrupts the heat transfer.
4. Valves are heated to a temperature at which indicators such as corrosion and oxidation increase significantly.

Based on all the above, it can be concluded that the adjustment of the gaps should be performed at mandatory. The process must be implemented in the presence of such signs as:

• at the top of the head of the block of installed cylinders, a stranger is noted, a little ringing noise;
• carried out repair of the gas distribution mechanism;
• adjustment was made more than 20 thousand kilometers ago;
• explicit reduction in the return of the engine;
• increase fuel consumption.

Motors of modern cars are arranged in such a way that thermal gaps need to be adjusted manually. For some, it may seem simple, someone considers this process to be serious and responsible. It all depends on the driver's experience, from the presence of certain skills and tools. In addition, there is no difference between diesel and gasoline engines. The process of adjustment is carried out here by the same scheme.

It is advisable to combine the adjustment with the oil change. This will avoid getting into the dirt, sand and dust engine.

Gap measurement

The definition and verification of which clearances on the valves are present, should be carried out exclusively on the cold engine.

To carry out this operation, it will be necessary to prepare probe and other additional tools whose choice depends on the category of valve pusher. It can be a cape or horn key, hammer, micrometer or a decor. The processes associated with measuring gaps are carried out in different ways.

To measure the heat gap on the pusher with a special screw adjustment, the crankshaft must be rotated so that its cam is directed in the opposite direction from the pusher. Next, you need to slightly hit the hammer over the pusher and the hands to squeeze it a little on the sides. With the help of the probe, the gap between the valve and the pusher is measured, and then they are checked with the meaning, which is indicated in the operating instructions.

For measurement thermal clearance On the motor with adjustable washers, the crankshaft must be deployed so that the cam selected valve is shown up. With the help of the probe, measurement is carried out and also compared with the indicators in the instructions for the car.

If, as a result of the measurements, it becomes clear that the indicators are rejected from the norm, it will be necessary to adjust.

Adjusting valve gaps

The process of adjustment is carried out by several steps. Special attention It is paid to the preparatory work aimed at the preparation of the premises and the car. Each process should be considered in more detail.

Preparation

Before proceeding with adjustment work, it is necessary to carefully clean and wash the body of the vehicle. It is important to completely remove dust and dirt from the boost space. It is necessary in order to make anything superfluous in the motor after the cylinder head cover will be removed.

After that, the car is installed on the maximum smooth surface, thoroughly tighten the parking brake and be sure to put special stops under the wheels. It is advisable to take care that in the room where the work is carried out uniform and moderately bright lighting.

It is equally important to prepare the necessary tools for adjusting:

• set of wrenches;
• dumping;
• special measuring probe;
• tweezers;
• micrometer;
• set of adjusting washers;
• device for adjusting valves.

Another important criterion for the preparatory work is the mandatory removal of the head of the cylinder block. In the process installation GBC. On the car and during the stretch there is a possibility of displacement of the gaps towards the plus or minus. It is for this reason that you need to be reinsured and once again to recover.

This method of changing the gap indicators is carried out using the probe. On modern cars for such a procedure, adjusting valve washers are involved. The sequence of actions here is as follows:

1. It is required to depart the valves of the tube and covers, as well as cables that lead to dampers drives, and disassembly air filter. You can unscrew the candles so that the crankshaft is scrolled easier.
2. Two nuts are unscrewed, the lid is removed, and the remnants of automotive oil are removed from the top.
3. The timing belt casing is removed.
4. The cylinder piston, where the regulatory process comes from, is displayed in the upper point of compression. For more accurate results, it will be possible to navigate the labels applied by the manufacturer.
5. Crankshaft turns on the asterisk and strictly clockwise. In order for the adjustment to be made as correct as possible, it is necessary to ensure that the risks on the housing of the bearings and the crankshaft completely coincide.
6. On the screw, which is used to install the gap, should be squeezed. The clearance is exhibited so that the flat probe is the maximum of the bolt's sovereign. As soon as the locknut is delayed, it is necessary to check the correctness of the indicators, since with a strong tightening they can move.

This process is carried out with all the remaining valves.

Regulation using rail and indicator

To adjust the automotive thermal gap, a special rack is often used, simultaneously with the indicator. These fixtures allow you to achieve maximum accuracy, which cannot be obtained by the method described above. The order of work here is set as follows:

• after the preparatory work and removal of valve covers, the motor must be scrolled to the coincidence of labels on the camshaft gear and the label on the housing;
• a marker on the reverse side of the built-in gear must be improving its badges. It is necessary to do it every 90 degrees, a relatively installed tag manufacturer;
• with the help of three bolts, you need to fix the rail on the protrusion of the block of installed bearings;
• in a special jack on the bar, you need to put the arrow indicator. At the same time, the scale must be installed on the zero mark;
• with the help of a special device, the cam takes and stretches up a little. With a normal defoculation, the indicator arrow will shift about 50-52 divisions.

If, as a result of the activities, the parameters obtained are somewhat different, it will be necessary to adjust the method described above.

At the end of the adjustment process associated with installing gaps in the valve mechanism, you need to start the engine and listen as it does its work in different modes. If the manipulation was performed after restoring the head, it is required to ensure that the valves are properly pronounced.