If you want your machine to always work in excellent condition, you need to periodically pay attention to its repair and diagnostics. In particular, it means work. What is the procedure for tightening the cylinder head VAZ 2106? How does the process take place and what is needed for this? We invite you to learn more about it here.
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When is it necessary to puff?
Unfortunately, not everyone understands how important this moment is. And even more so, not every motorist is aware of what the tightening procedure should be and how this procedure takes place. But this does not mean at all that you should not be interested in this, because every owner of the VAZ 2106 should understand how important this is. After all, the wrong moment and tightening procedure can subsequently turn to the owner of the vehicle by the failure of the cylinder head. And this, in turn, will entail considerable financial costs.
Previously, this procedure fell on the shoulders of the masters at service stations, because it was performed during the technical inspection of the machine. However, later this need for maintenance was canceled, so now it is the concern of motorists. To understand how important it is, consider the cases when you need to tighten the bolts and follow the order and moment of this action:
- If engine oil begins to leak from under the cylinder head. Sometimes this is due to worn cylinder head gaskets, but it can also be due to loose head screws. This is evidenced by an oil stain that appeared at the junction of the head with the block.
- After disassembling the VAZ 2106 internal combustion engine, you first need to follow the order and tightening torque of the screws. In case of non-compliance with this procedure, problems are provided to your car.
- In addition, experienced drivers advise beginners to carry out this procedure from time to time, preferably every two to three thousand kilometers. After all, the masters at the service station periodically encounter the fact that the cylinder head bolts are loosened during the operation of the motor.
Accordingly, if you disassembled the head or saw an oil stain at the junction of the cylinder head with the block itself, then you need to tighten the screws.
We do everything with our own hands
Sometimes inexperienced motorists perform actions that require certain knowledge and skills. And very often such repairs turn out badly for car owners. We strongly advise that you only tighten the cylinder block pins if you have already performed this procedure. Consider the process for a VAZ 2106 car. But keep in mind that each individual motor has its own specific work.
What to prepare?
In general, you will not need anything other than a torque wrench. When tightening, this special wrench will be simply necessary, since only with the help of this tool can the moment be determined. You are unlikely to find this key in home tools, so you should buy it at an auto store or take it to a service station for a while. Of course, hardly anyone will give it to you for free, since its cost varies from 1,200 rubles (350 hryvnia) and more.
It is also worth noting that very often "garage specialists" recommend using a regular wrench. Like, “well, what will happen to this, because the neighbor in the garage, Petrovich, on his“ husk ”generally tightened the bolts by eye, without any of these modern things.” To avoid negative consequences, it is better not to listen to such people, since not everyone is aware of the importance of this procedure.
When carrying out car maintenance, questions often arise that are only casually discussed on forums or in the literature. One of them is the tightening torque of the fasteners of the main components of the car. To find out all the nuances of fastening the cylinder head bolts, let's concentrate on the engine, the "heart" of the car. And with an understanding of the principles of the tightening torque of threaded connections, the knowledge gained will be easy to extrapolate to any vehicle node.
Tightening the bolts correctly
Any threaded connection is designed for a certain tightening torque. It is regulated by industry quality standards, for example, “OST 37.001.050–73 Tightening of threaded connections. Tightening standards ”and the governing documents of vehicle manufacturers. Foreign manufacturers use other standards, but basically they are similar to domestic ones. The information below will be presented based on Russian standards.
To what extent can threaded connections be tightened
Why is it important to maintain the correct tightening torque? Only proper tightening will ensure reliable fixation of the part, on the one hand, and prevent damage to the thread and / or the part itself, on the other hand.
Consider what happens when the tightening torque is exceeded using the example of a bolt with a nut:
- Immediate thread deformation. Due to too much applied force, deformation and stripping of the thread on the part occurs. The bolt or nut is not subject to further use, in addition, certain difficulties will arise when trying to unscrew the nut for replacement. Most likely, you will have to use a drill or a metal saw to cut the nut.
- Metal damage hidden from view. It may seem that the nut is tightened correctly, however, due to the excess of the yield strength, irreversible changes occur in the bolt or nut: deformation, violations of the metal crystal lattice. Such a case is especially dangerous, it is so imperceptible immediately, but after some time a bolt crack can lead to sad consequences.
The yield strength is called the mechanical characteristic of the material, which characterizes the stress at which the deformations continue to grow without increasing the load. Designation σ t.
The unit of measurement is Pascal [Pa] or multiples [MPa].
This is an important parameter by which allowable stresses for ductile materials are calculated.
After passing the yield point, irreversible changes begin to occur in the metal of the sample, the crystal lattice of the metal is rearranged, and significant plastic deformations appear.
Wikipedia
If, on the contrary, the nut is not tightened with the appropriate moment, after a while it will simply unscrew, which can also lead to undesirable consequences. Therefore, it is strongly recommended to tighten the threaded connections not “with all the force”, not by hand, but wisely, using special equipment.
Torque control tools
The main torque control tool is a torque wrench. This is the name of the wrench, which has a built-in dynamometer (a device for measuring the moment of force). There are the following types of devices:
For non-professional use or a small car service, an indicator or limit key is suitable, as the most affordable. Digital will be in demand in a large car service.
How to choose the force to tighten the connection correctly
When working with a key of the limit type, in order to achieve the required moment, one should:
- Before tightening, select the required tightening torque, e.g. 50 Nm. The force is set on the main scale of the device, but not 50, but 48 Nm.
- On the auxiliary scale, a force of 2 Nm is set, which in total will give us the required 50 Nm.
- Using a socket of the required size, tighten the nut. When a force of 50 Nm is reached, a click will be heard and tightening will stop.
Control over the effort when working with an indicator-type key is carried out visually.
In addition to the torque wrench, you can find torque screwdrivers and screwdrivers on sale, they work on the same principle. When choosing a torque wrench, remember that the tightening torque you need must be 25% less than the maximum allowable for the wrench. Using the key "at the limit", you quickly disable it. And also be sure to read the instructions for its use.
Well, you can check the correct tightening of the connection with a goniometer.
How to work with a homemade torque wrench
As a rule, a torque wrench is a rather expensive tool. Its purchase is unlikely to be justified for private use. However, the simplest device is easy to make yourself. For this you will need:
- conventional spring scales with a hook and a round scale, allowing you to weigh up to 20 kg (the so-called steelyard);
- a piece of a rather thick pipe (2.5 cm) about half a meter long.
Having fixed the hook of the scales at the end of the pipe, insert the wrench into the other end and pull the scales, tightening the nut. In this case, to create a moment of 10 Nm, it will be necessary to apply a force of 2 kg. According to this scheme, you can calculate in advance what effort in kilograms you will need to apply to tighten.
Of course, a homemade key will have a rather large error, but it's still better than nothing.
Video: how to make a torque wrench with your own hands
Standard Cylinder Head Bolt Torques
To know for sure how much torque to tighten a particular threaded connection, you can use the following data.
Table: Tightening torques for connections depending on the thread diameter
| Nominal thread diameter | Turnkey size of the head, bolt (nut), mm | Thread pitch, mm | Strength classes according to GOST 1759–70 | ||||
| Bolt | |||||||
| 5.8 | 6.8 | 8.8 | 10.9 | 12.9 | |||
| screw | |||||||
| 4;5;6 | 5;6 | 6;8 | 8;10 | 10;12 | |||
| 6 | 10 | 1 | 0,5 | 0,8 | 1,0 | 1,25 | 1,6 |
| 8 | 12 - 14 | 1,25 | 1,6 | 1,8 | 2,5 | 3,6 | 4,0 |
| 10 | 14 - 17 | 1,25 | 3,2 | 3,6 | 5,6 | 7,0 | 9,0 |
| 12 | 17 - 19 | 1,25 | 5,6 | 6,2 | 10,0 | 12,5 | 16,0 |
| 14 | 19 - 22 | 1.5 | 8,0 | 10,0 | 16,0 | 20,0 | 25,0 |
| 16 | 22 - 24 | 1,5 | 11,0 | 14,0 | 22,0 | 32,0 | 36,0 |
| 18 | 24 - 27 | 1,5 | 16,0 | 20,0 | 32,0 | 44,0 | 50,0 |
| 20 | 27 - 30 | 1,5 | 22,0 | 28,0 | 50,0 | 62,0 | 70,0 |
| 22 | 30 - 32 | 1,5 | 28,0 | 36,0 | 62,0 | 80,0 | 90,0 |
| 24 | 32 - 36 | 1,5 | 36,0 | 44,0 | 80,0 | 100,0 | - |
Main threaded connections in the engine
The list of the main threaded connections of the engine and the features of their tightening:
- Cylinder head (cylinder head). A very important knot, therefore, when attaching it to the block, it is important to observe not only the tightening torque, but also the order in which the bolts are tightened. As a rule, the cylinder head is tightened with a rather large moment, starting from the center of the block to the edges in several passes. Be sure to specify this information in the car's operating manual (for each engine model, the numbers and order may be different)!
- Valve lid. Due to the small diameter of the valve cover studs, special care must be taken when tightening them and not to exceed the required torque. Also check the tightening order and torque in the manual.
- Spark plugs and glow plugs. They are tightened in random order, but very carefully, since if the threads in the engine are damaged, expensive repairs will be required.
- When tightening the nozzles, also be careful: due to their small diameter, it is easy to damage the threads.
- The engine mounts should be tightened after the engine is fully installed, when it already rests on them with its weight. If the chocks are tightened before the engine rests completely on them and the jack is removed, the chocks will quickly tear during operation.
So, now you know the basic rules when working with threaded connections. If you don't have a torque wrench but need to tighten something in the engine, it's best to purchase or borrow one from someone. As a last resort, use a home-made one, but do not tighten the nuts “by eye”, this will most likely harm both the engine and your wallet, repairing an internal combustion engine in used cars is not a cheap pleasure.
The cylinder head (cylinder head) provides sealing of the combustion chamber, and is also the basis for the gas distribution mechanism. During operation, the cylinder head is affected by high temperature, strong vibration and other factors. If the cylinder head bolts are not tightened correctly, the combustion chamber may lose its tightness, the gasket may burn out, or the body of this part may crack.
What forces act on the cylinder head while the engine is running
Any mode of motor operation leads to uneven heating of the head. The areas located above the combustion chambers heat up much more strongly than the rest of the body, which causes thermal stress on the metal. The higher the engine speed or the stronger the load on it, the greater the difference in heating of various sections of this part. In some areas, the thermal expansion of the aluminum from which the body of this part is made is so strong that it increases the pressure on the gasket between the head and the cylinder block. Therefore, after a certain period of time, it is necessary to repeat the tightening torque of the screws, otherwise the gasket is likely to burn out.
What forces act on the cylinder head while tightening the screws
The gasket, which is installed between the cylinder block and the cylinder head, has a certain thickness, which decreases during tightening. Despite the overall rigidity, the aluminum body of this part deforms during tightening by thousandths of a millimeter, so it is necessary to carry it out from the center to the edges. In this case, it is possible to compensate for the bending of its surface (sole). When the head rests on the cylinder block, the pressure on each section of its sole is the same. As you twist, the pressure in the places where the bolts (screws) are installed increases, which leads to a V-shaped deformation of the sole. To avoid this, it is necessary to strictly follow the sequence of actions. If the tightening order is violated or the force (torque) does not match the motor, the likelihood of gasket burnout and engine repair increases.
Correct tightening order
Regardless of the type of engine, the cylinder head tightening procedure is always the same. Each head is tightened with two rows of screws running parallel to the combustion chambers. The order of the holes is from the first to the last cylinder, on the right and left, relative to the first cylinder, in a row. Here is the correct order to tighten the screws:
Some masters prefer a different order. First, 2 central bolts are tightened (the torque is the same as described above), then the screws on the left and right in one row, and then also in another row. Then continue to tighten the remaining bolts in the same order. Both the order of tightening the head are the same in terms of efficiency, so everyone chooses what he personally likes. The main thing is to ensure the correct force during tightening. Having tightened all the cylinder head bolts, they begin to tighten in the same order. The moment should be 3–4 kgf.m. Then, following the same order, tighten again with a force of 7–8 kgf.m. The maximum torque depends on the make and model of the car, so before starting work, you must carefully read the repair instructions for your car. Otherwise, there is a high risk of damage to the head or cylinder block.
On some vehicles, cylinder head bolts can be reused by making sure they are within the recommended lengths. On other machines, it is desirable to use new parts every time.
Use a torque wrench for correct tightening.
If the length of the screw is longer than necessary, then it will rest against the bottom of the well. Attempting to tighten it will cause the head of the bolt to break off or it will strip the threads in the well. In any case, you will have to disassemble the motor, change the gasket and most likely restore the well. It will cost much more than a new set of screws.
After 300–700 kilometers (depending on the type and model of the engine), a cylinder head broach is necessary. During this run, high temperatures and vibration caused the gasket to shrink, so the bolts must be re-tightened. It is usually enough to turn each bolt 1-2 times 90 degrees, focusing on the readings of the torque wrench, so as not to exceed the torque. The tightening procedure is the same as before.
Conclusion
Now you know how the cylinder head is tightened and what mistakes are made during this operation. This will help you in self-repair and maintenance of your car.
Tighten bolt? What's the problem: a wrench and ... go ahead, tighten yourself to the stop.
So a person who has little idea of \u200b\u200bthe importance of the correct tightening order of the cylinder head bolts will think. And what kind of engine malfunctions can lead to a violation of the procedure and technology for tightening the cylinder head bolts. In fact, this is a very sensitive question, so let's figure it out.
Why does a motorist need to know the procedure for tightening the cylinder head?
Naturally, if you have a lot of banknotes and even shake out the ashtray in the cabin, you are going to a car service, then there is no need. But for those motorists who want and can repair a car in general, and in particular, this information will not be superfluous.
It is important! Before we share with you the features of the cylinder head tightening order, you should pay attention to the fact that each engine model has its own bolt tightening parameters.
In no case, especially when working with the cylinder head of modern cars, should you rely on your knowledge and experience gained during the repair of the cylinder head on other engines. The procedure for tightening and tightening the cylinder head bolts is carried out in strict accordance with the manufacturer's requirements for this engine. You can easily find these parameters in the manual for the repair and maintenance of the engine.
Knowing the order of tightening and tightening the cylinder head will not be needed so often. In the event that it is necessary to replace the cylinder head gasket or when repairing the engine.
What are the common features of cylinder head tightening technology
Let's start with the fact that, according to the old memory of operating domestic car models, many motorists are worried about the need for preventive broaching of cylinder head bolts. Especially after an engine overhaul or cylinder head repair.
Broach of the cylinder head in modern engines is not required. This is due to the fact that for fastening the head to apply
self-tightening bolts or so-called "spring bolts".
Their characteristic is such that after the first tightening they no longer need to be drawn during the period of operation. Moreover, broaching the cylinder head in this case can only damage the quality of the bolts.
If earlier, cylinder head broaching was one of the mandatory maintenance items for a car, today this item can only be applied to obsolete models of Moskvich, GAZ and VAZ engines.
Rules for tightening the cylinder head
With different parameters and characteristics, the general rules for tightening bolts are in principle applicable to all types of engines.
- Mandatory use of the manufacturer's parameters for: the order (scheme) of tightening the cylinder head bolts and the tightening torque.
- When tightening the cylinder head, use only a serviceable and tested torque wrench, and not a simple wrench. In this case, the eye and the hope for muscle memory are not helpers.
- A mandatory requirement is the ideal condition of the cylinder head mounting bolts: in no case should you use old bolts, do not install cut bolts, check the condition and cleanliness of the thread before tightening. The repeated use of "spring" bolts will no longer provide the necessary tightening force, which will eventually lead to oil leakage from under the cylinder head gasket.
- It is strictly forbidden to tighten or tighten the cylinder head with TTY type bolts (this type of bolt is used mainly on aluminum cylinder heads). TTY bolts are not tightened to the torque, but to the set degree. This information should be in the manufacturer's instructions.
- When buying a cylinder head gasket, it should have the manufacturer's specification, which indicates what torque is applicable to this particular type of gasket. This must be taken into account so that the figures for the engine tightening torque and the gasket tightening torque do not diverge dramatically.
- If the hole for the cylinder head bolt is “blind”, then pouring oil into it before tightening the head, try not to overfill. Otherwise, the bolt will not reach the end. If the hole is through and goes into the cooling system, then before screwing in the bolt, lubricate the thread with plastic sealant.
If you still decide to tighten (broaching) the cylinder head bolts, then take into account that it is done: for an engine with a cast-iron cylinder head - to “hot”, i.e. at least 80 0 engine temperature, for an engine with an aluminum cylinder head to "cold".
Each car owner who is faced with the repair of the cylinder head, after completing the task, will have to put this element in place. This procedure means If this is not done, the tightness of the unit may be broken. Below we will analyze which torque of the head of the VAZ 2106 block is most important and what to consider when installing the device.
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When is it necessary to puff?
To begin with, let's consider in which cases it is necessary to broach the bolts of the cylinder head of a VAZ 2106 car engine:
- If engine oil comes out from under the cylinder head. The problem indicates damage or natural wear of the head gasket. The seal must be removed and replaced. The leak could also be due to loose bolts on the cylinder head. The presence of a problem is evidenced by oil stains that appeared at the junction of the head with the motor block.
- After the repair of the power unit. If you removed the mounts in a Niva car or any other and sorted out the engine, then for a successful assembly, you should take into account the tightening order and the diagram, as well as the tightening force of the screws.
- For prevention purposes. Experts recommend tightening the bolts on the cylinder head every 2-3 thousand kilometers. When the engine is running under vibration conditions, it can cause the screws to loosen, so they must be checked periodically and tightened with proper force.
The Garage Ilyich channel published a video that will allow you to understand the process of tightening the bolts of the block head on the "six".
How to tighten correctly?
You can stretch the bolts with the help of specialists or on your own. If you have never encountered the need to perform this task before, then below we will analyze how much the screws should be tightened and in what sequence to do it.
Accurately observe the tightening torque, because if the block head bolts are overtightened, this will lead to cracks and damage to the cylinder head. If this happens, the car owner will have to overhaul the unit. The working surface of the hole, as well as the threaded connection of the screw, must be as clean as possible. An iron wire brush can be used to clean the cylinders. If during the course of the task you find "blind" holes for the head screws, then carefully use the lubricant for processing. If the volume of the substance is greater than required, it will be difficult to install the pin all the way.
Before tightening, it is necessary to make a visual diagnosis of the condition of the bolts. If the fastening elements are damaged or worn, their quality is generally poor, then it is better not to tighten these screws, it is recommended to change them for new ones.
Tools and materials
To tighten the cylinder head, prepare only one tool - a torque wrench, which will allow you to determine the tightening force of the screws. It is best to buy a key in a specialized store or rent it at a service station, since this tool can only be used for twisting and tightening. The operation of a conventional wrench will not allow you to determine how many kilograms the tightening force is.
Channel "Engine Repair! And interesting!” published a video that describes all the nuances of the stretching process.
Action algorithm
The sequence and strength needed when you pull the cylinder head bolts:
- In accordance with the diagram below, tighten all bolts using a torque wrench. The tightening torque on the first circle of tightening the fasteners will be about 3.5 - 4.1 kgf / m. First, the bolts are tightened, which are located in the center of the block head - above and below. After that, two upper and lower fasteners are screwed, installed on the side of the screws located in the center. Then the two extreme bolts are tightened. Note that you need to tighten the left pins first, and then the right ones. Screw number 11, located at the bottom left, does not need to be touched.
- This is the first round of stretching. At the second stage, the bolts are tightened in the same order. Only the force with which the fastening elements are pulled by the tool will be 10.5 - 11.5 kgf / m.
- At the third stage, the bolt is tensioned, which is marked with the number 11 in the diagram. The tightening force of this screw should be 3.5 - 4.0 kgf / m.
