Diagnostics and replacement of the camshaft on a VAZ 2107

The camshaft, like any important component of an engine's design, affects its performance. Even minor defects in this device can negatively affect the engine power and its traction characteristics. This may also lead to unreasonably high gas mileage, and in the long run will lead to serious breakdowns requiring expensive repairs.

Next, we will discuss why a distribution valve is needed on the VAZ 2107, how to diagnose it and troubleshoot it yourself.

Purpose and principle of operation

The camshaft is a metal rod on the axis of which eight cams are placed. These are parts that have an irregular shape. They rotate on the axis of the camshaft and are located opposite the inlet valves of the cylinders. Their rotation ensures stable combustion of the fuel mixture inside the cylinders. All these mechanisms are brought into precise synchronization.

Thanks to the proper operation of the shaft, a mixture of air and fuel is released into the cylinders in a timely manner, compression and release of exhaust gases occurs. On the Classic, the camshaft is driven by the fact that its gear rotates as a result of interaction with the crankshaft sprocket through a chain.

On the VAZ 2107, the camshaft is located at the top above the cylinder block. Thanks to this, it is available for self-replacement. This also makes it possible to easily adjust valve clearances.

To better understand the principle of operation of the camshaft, watch the video tutorial.

Why install a different camshaft?

The main reason for installing a new part is to replace it in case of failure. But sometimes such a decision is made for other reasons. For example, a car owner dreams of improving engine performance. And for this he begins to tune the engine. It is believed that a more advanced camshaft can help improve engine performance.

How is this achieved? Another device may make it possible to increase the valve lift and the width of the engine's operating phase. In theory, this should help produce more mixture, which will improve performance.

And there are so many things that numerous “amateurs” are trying to cram into the cylinder head. But there is only one car that can become a “donor” for installing a new device. And this is everyone’s favorite Niva (VAZ 21213). The Niva camshaft is an ideal solution for tuning the 7 engine!

The phase width of this part, as well as its intake valve lift, are relatively suitable for the operation of the Seven engine. And the engine receives an increase in power of about 2 horsepower. Of course, this is not such a big deal. But at the start the car responds a little better.

If a car enthusiast is willing to pay money for a special “sports” shaft, then he may well buy one that is manufactured in domestic factories for this purpose. Today you can find a worthy “comrade” within 10 thousand rubles.

How is the price determined?

The cost of the part depends on the design features. A classic type element will be inexpensive. The price increases when the part parameters change. The amount can increase 10 times . It is not recommended to choose based solely on cost. The performance of the spare part is important.

The price increase is facilitated by transportation costs for delivery to the seller, the final buyer. The marketing characteristics of those who are part of the product sales chain can have an impact. These factors are of low quantitative expression.

Causes and types of malfunctions

During its operation, the timing shaft is constantly exposed to high temperatures and high dynamic loads. Therefore, it inevitably loses its properties and fails. When this happens, the driver begins to feel that the engine is losing power, and under load, a slight knocking noise occurs in the engine. If this happens, it's time to open the cylinder head.

So what could happen?

1. The cams or journals are worn out. Any part that rotates during its operation will naturally begin to wear out over time. The wear process can be accelerated by low oil pressure or poor quality, as well as manufacturing defects of the part itself. Worn cams cannot lift the intake valve properly, resulting in less fuel entering the cylinder than needed.

2. Camshaft deformation. Severe overheating of the engine, which occurs when the lubrication is not working well or when there are problems in the cooling system, leads to this type of breakdown. The malfunction can be identified by a characteristic knocking sound. It is prohibited to operate the car in this case - otherwise you can easily damage the operation of the entire gas distribution mechanism.

3. Shaft fracture. Sometimes it happens that the camshaft simply breaks, which may be a consequence of desynchronization in the timing system. The engine stops working, the valves become bent, the guides are damaged, and the piston group mechanisms are destroyed.
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Do it yourself: Replacing the camshaft, rockers and caps of the VAZ-2107

Hello everyone, I decided to replace the camshaft with rockers, and at the same time the valve stem seals. The previous owner already changed the factory camshaft and rocker at 120 thousand km, now the mileage is approaching 230 thousand km, so I think it’s time, especially since the last adjustment of the valves did not give any results - the chirping sound did not change in any way, so there were suspicions about wear cams with rockers. The oil is still leaking, and then suspicions fell on the valve stem seals, since there were characteristic signs of their wear - when starting up after an overnight stop, there is a lot of smoke from the exhaust pipe in the first seconds.

Well, and the carving of candles in soot.

Also, when inspecting the cylinders with an inspection camera, wet smudges were discovered on the exhaust valves.

So, I purchased a camshaft assembly, a set of rockers with new-style adjusting bolts, Reserve oil seals (they seem to be praising them), a couple of crackers and springs, just in case. Among the tools, I bought a desiccant, a mandrel for stuffing oil seals, I didn’t buy a puller (the toad strangled me), instead I bought narrow-nose pliers.

We remove the valve cover, set the TDC marks on the 4th cylinder, remove the camshaft sprocket with the chain so that it does not jump, tie it with a rope with the star, since you will then have to turn the crankshaft again.

Then I removed the camshaft, disassembled it and wiped off the oil to get a better look.

How to remove the camshaft

Diagnostics, repairs and measurements of the shaft are carried out only after it is removed from the engine. To work, you need to prepare 13 mm and 10 mm socket wrenches, 17 mm open-end and torque wrenches, as well as pliers.

Dismantling is carried out in the following sequence:

1. The car starts on a level surface.
2. The air filter housing is removed.

3. Using pliers, the throttle cable is removed from the carburetor, as well as the longitudinal rod of the throttle valve.
4. It is better to move the fuel hose to the side and secure it.
5. Using a 10mm wrench, you need to unscrew the fastenings of the chain tensioner to the cylinder head and remove it.
6. Using a 10mm wrench, unscrew the nuts that secure the valve cover.
7. Now the cover is easily removed, and after it the rubber gasket is also removed.
8. Using a slotted screwdriver, you need to straighten the lock washer, which is located in the place where the shaft star is attached.

9. To perform the following work, you need to put the gearbox in first speed. Then you can use a 17mm wrench to unscrew the bolt that secures the camshaft gear.
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10. Now it is easy to remove it along with the chain.

11. Now is the time to remove all the nuts that secure the camshaft to the bed. The key to 13 will help us with this.

12. Now the camshaft is easy to remove along with the “bed”.

13. Using a 10mm wrench, unscrew the bolts that secure the flange and the flange is disconnected.

14. The camshaft is now easy to remove from the “bed”.

Installation of camshaft VAZ 2107

The cylinder head camshaft is installed in the reverse order of removal. Before installing the part into the housing, it is necessary to lubricate the support journals with engine oil. When assembling, you should pay attention to two important points:

• correspondence of the marks on the camshaft and on the sprockets of its drive;
• tightening torque of the camshaft housing nuts.

First, you need to properly tighten the camshaft nuts. The nominal tightening torque of the nuts is 2.2 kgf•m. You cannot immediately tighten the fastening to such a torque. The VAZ 2107 camshaft is tightened in three to four stages so that the body is pressed evenly, without distortions. The nuts should be tightened from the center to the edges, in accordance with the “tightening chart” (see figure).

When the camshaft is installed, it is necessary to set its position relative to the crankshaft. There are marks on the camshaft bed, the front engine cover and the crankshaft and camshaft sprockets that should be followed. Even if the drive chain has been securely attached to the sprocket, when installing the camshaft, make sure that its position matches the position of the engine crankshaft. To correctly set the marks on the VAZ 2107 camshaft, you must perform the following steps:

• make sure that the mark on the crankshaft pulley is located opposite the long mark on the front engine cover (this corresponds to the top dead center of the fourth cylinder);

• install the sprocket on the camshaft and make sure that the mark on it matches the mark on the “bed”;

• put the chain on the sprockets without disturbing the position of the shafts;
• make sure that when the chain is tensioned, the marks match;
• tighten the camshaft sprocket bolt;

• turn the crankshaft two turns with the wrench;
• check the alignment of the marks on the camshaft and crankshaft;
• if necessary, change the position of the chain on the camshaft sprocket;
• Tighten the camshaft sprocket bolt and secure the lock washer.

After this, all that remains is to adjust the chain tension using the tensioner and complete the assembly by installing the cylinder head cover and other parts.

Timing shaft diagnostics

In the removed state, you can easily assess what defects are on the shaft. Visually, you can detect damage such as scuffs and scratches, as well as wear on the cut on the cams and coating of the aluminum word on the necks.

Even if minor traces of deformation were noticed, the camshaft on the VAZ 2107 must be replaced.

We present a table that shows the permissible values ​​of the dimensions of the shaft journals for its further use.

If these values ​​are not met, it is important to replace the “bed” or timing shaft.

Summary characteristics of VAZ 2101-2107 and Niva camshafts

Here I will provide a summary table of camshaft . I'll start with the standard and familiar 2101 to purely sports shafts. In general, the characteristics of camshafts are given on the manufacturers’ websites, but for some reason no one wanted to collect all the information together. I will also give a definition of terms related to camshafts. The most frequently mentioned terms are: phase, rise, overlap, and sometimes the base is indicated.

Phase - the duration of the valve position in the open state. It is measured in degrees of rotation angle of the car's crankshaft and shows at what angle the crankshaft will turn during the time the valve is open. Lift is the maximum amount of valve travel. Measured in millimeters. Overlap is a value measured in degrees of crankshaft rotation angle. Makes it clear how long both valves of one cylinder are in the open position. Also, overlap is measured in millimeters. Knowing the amount of overlap in millimeters, you can judge whether the valves will hit the piston because When the valves are in the overlap, the piston moves near top dead center (TDC). The term base usually refers to the diameter of the round section of the camshaft cam. Measured in millimeters. So if the diameter of the round section of the camshaft cam corresponds to the standard one, i.e. 30mm for a classic VAZ engine, then the camshaft is considered full-base, and if it is smaller, it is not full-base. The vast majority of tuning camshafts are incomplete. Also, when selecting and installing a camshaft, you should understand that shafts with a lift of more than 12 mm require valve seats to settle. You can find out more precisely the required amount of valve drawdown on the camshaft manufacturer’s website.

Type Inlet Exhaust overlap base Lift, mm phase, gr. Lift, mm phase, gr.

2101 9.5mm 232gr. 9.5mm 232g 0.5mm 22g 30mm 21213 10.6mm 243.5g. 9.5mm 229g 0.5mm 23.5g. 30mm STI-1 10.7mm 266gr. 10.7mm 266g 1.7mm 48g no info. STI-2 11.2mm 280gr. 11.2mm 280g 2mm 64g. no info STI-3 11.7mm 293gr. 11.5mm 285gr. 2mm 65gr. no info STI-4 12.1mm 309gr. 12mm 301gr. 3mm 81gr. 28.8mm Dynamics 113 11.3mm 244g. 10.2mm 234gr. 1.2mm 36gr. 30mm Dynamics 115 11.5mm 290 gr. 11.5mm 290gr. 2.1mm 78gr. 29.4mm Dynamics 118 11.8mm 260g. 11.3mm 246gr. 1.3mm 39gr. 29.4mm Dynamics 125 12.5mm 322gr. 12.2mm 318gr. 4.5mm 108g 27mm Dynamics 130 13mm 335g. 13mm 335gr. 5.5mm 125gr. 26.6mm Estonian 1 10.5mm 256gr. 10.5mm 256gr. 1.5mm 44gr. no info Estonian 2 11.2mm 289gr. 11.2mm 289gr. 2mm 77gr. no info Engine M12 12.8mm 307gr. 12.2mm 298gr. 2.2mm 83gr. 27.5mm M22 engine 13mm 316gr. 12.4mm 307gr. 3.2mm 97gr. 27mm M32 engine 13.2mm 325gr. 12.7mm 317gr. 4.2mm 112gr. 26.5mm MM M3 13mm 332gr. 12.5mm 332gr. 5.1mm 135gr. no info MM M4 12.5mm 339gr. 12.7mm 322gr. 5.1mm 130g. no info Needs 11.8 11.8mm 296g. 11.8mm 296gr. 3.5mm 84gr. no info

Of course, there are other camshafts in nature, but they are much less common. Also, the names of camshafts may differ in different sources. OKB Dynamics is currently marking its camshafts with a new designation. For example, Dynamics 118 is also Dynamics 51.

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