Diy repair of the cylinder head of the prior 16 valves

• Cylinder head parts
• 1 - block head
• 2 - intake camshaft
• 3 - stuffing box
• 4 - the exhaust camshaft
• 5 - camshaft bearing housing
• 6 - block head cover
• 7 - bracket for attaching the wiring harness
• 8 - plugs
• A - the distinctive belt of the intake camshaft

The head 1 of the cylinder block, common for four cylinders, is cast from an aluminum alloy, with hip-shaped combustion chambers. The inlet and outlet channels are brought out to different sides of the block head. The valves are arranged in a V-shape in two rows: on the one hand the intake, on the other - the exhaust.

Sintered valve seats and brass valve guides are pressed into the head. The inner diameter of the guide bushings is (7 ± 0.015) mm, the outer diameter (for bushings supplied as spare parts) is 12.079-12.090 mm and 12.279-12.290 mm (the bushing is increased by 0.2 mm).

The diameter of the disc of the inlet valve is 29 mm, the diameter of the outlet valve is 25.5 mm. The diameter of the inlet valve stem is (6.975 ± 0.007) mm, the diameter of the outlet valve is (6.965 ± 0.007) mm.

One spring is installed for each valve. The length of the spring in a free state is 38.19 mm, under a load of (240 ± 9.6) N [(24.5 ± 0.98) kgf] should be 32 mm, and under a load of (550 ± 27.5) N [( 56.1 ± 2.8) kgf] - 24 mm.

The valves are actuated by camshaft cams through cylindrical hydraulic pushers located in the guide holes of the cylinder head along the axis of the valve holes. Hydraulic pushers automatically eliminate valve clearance, so there is no need to check and adjust valve clearance during maintenance.

Oil for the operation of the Lada Priora hydraulic pushers is supplied from the lubrication system along a vertical channel in the cylinder block to the channel in the cylinder head near the 5th mounting bolt, and then along the upper channels made on the lower plane of the bearing housing. Through the same channels, oil is supplied to lubricate the camshaft journals. A check ball valve is located in the vertical channel of the cylinder head, which prevents the oil from draining from the upper channels after the engine is stopped.

Two camshafts are used to drive the valves: intake and exhaust. The shafts are cast from cast iron and equipped with five bearing journals, which rotate in seats made in the cylinder head and in one common camshaft bearing housing. To increase wear resistance, the working surfaces of the cams and the journal for the oil seal are bleached. In order to distinguish the intake camshaft from the exhaust camshaft, a distinctive band A is made on the intake shaft near the first support.

The shafts are held against axial movements by thrust collars located on both sides of the front support. The front ends of the priora camshafts are sealed with self-tightening rubber seals. The rear holes located along the axis of the shafts in the cylinder head of the Lada Prior and the bearing housing are closed with rubberized cap plugs.

You will need: a device for compression of valve springs, a tool for pressing out and a mandrel for pressing in valve stem seals, socket wrenches "for 8", "for 10", "for 13", keys "for 19", "for 21", a hexagon "for 10 ", screwdriver, tweezers.

1. Remove the cylinder head from the engine (see "Replacing the Lada Priora cylinder head gasket").

2. Install the cylinder head with the camshafts up, placing wooden spacers under it so as not to damage the valves.

3.Unscrew the three nuts securing the left support of the power unit with a socket head "13" ...

5. Unscrew the two bolts securing the fuel pipe bracket with a key "10" ...

7. Unscrew with a key "10" the two bolts of the phase sensor ...

9. Unscrew the emergency oil pressure drop warning lamp sensor from the camshaft bearing housing with a 21 key.

10. Remove the coolant temperature sensor from the thermostat with a key "19".

11. Unscrew the coolant temperature gauge sensor from the rear end of the block head with a 21 key.

12. Unscrew the two nuts of the VAZ 2170 thermostat using a 13-key.

14. ... and the gasket installed underneath.

15.Unscrew the spark plugs with a spark plug wrench so as not to accidentally damage them.

16. With the socket head "8", unscrew the twenty bolts securing the camshaft bearing housing of the Lada Prior.

18. Remove the camshafts from the cylinder head supports of the VAZ 2172 and remove the oil seals from their front ends.

19. Remove the plugs from the rear end of the block head.

20. Remove the valve pushers from the holes in the cylinder head.

21. Clean carbon deposits from combustion chambers. Inspect the head of the Lada Prior block. If it has cracks or traces of burnout in the combustion chambers, replace the head. Remove burrs and nicks from the plane of the block head.

22. Check the flatness of the surface adjacent to the cylinder block of the Lada Prior. To do this, place the ruler with an edge on the surface of the head, first in the middle along and then along the diagonals and measure the gap between the surface of the head and the ruler with a feeler gauge. If the gap is greater than 0.1 mm, the mating surface can be sanded. To do this, contact a specialized workshop.

23. Similarly, check the flatness of the mating surfaces of the block head under the intake manifold ...

24. ... and a katkollektor. The flatness of these surfaces should not exceed 0.1 mm.

25. To check the tightness of the Prior's fret block head, plug the hole in the head for the thermostat socket. This can be done, for example, by placing a blank spacer made of thick cardboard under the socket and tightening its fastening nuts. Reinstall the coolant temperature gauge sensor if it was turned out.

26. Pour kerosene into the water jacket channels. If the level of kerosene drops after holding for 15–20 minutes, it means that there are cracks in the head and it must be replaced. Remember to remove the cardboard spacer and plugs after checking.

27. Check the condition of the bearing surfaces for the camshaft journals on the block head ...

28. ... and bearing housing. If at least one of them shows signs of wear, scoring or deep marks, replace the head and bearing housing.

29. Flush the oil passages. To do this, plug the vertical oil channel of the VAZ 2171 from the side of the combustion chamber (the channel is located between the 3rd and 4th cylinders).

thirty. . pour gasoline into the oil channel of the block head ...

31. ... and the camshaft bearing housings and soak for 15–20 minutes. Pour out the gasoline, remove the plug and finally flush the channels with gasoline using a blower.

32. To check the tightness of the valves, screw in the candles and pour kerosene into the combustion chambers. If, within 3 minutes, kerosene does not leak from the combustion chambers into the channels, the valves are tight. Otherwise, grind (see "Lapping the valves") or replace the valves.

To replace or lapping the valves, remove the following parts from the cylinder head: 1 - valve; 2 - spring; 3 - plate; 4 - crackers.

33. Place a suitable stop under the valve to be removed.

34. Install the device for compression of the prior valve springs by screwing the camshaft bearing cap fastening bolt into one of the holes in the block head and hooking the tool onto this bolt. Compress the valve spring with a tool.

35. Remove the two crackers from the upper spring plate using tweezers or a magnetized screwdriver. Then remove the fixture.

If the force of movement of the lever of the device increases significantly, and the crackers do not come out of the valve groove, apply a light blow with a hammer on the spring plate to release the crackers.

36. Remove the spring plate.

37. Carefully remove the spring.

38. Push and remove the valve from the block head.

39. Press the valve stem seal off the valve guide with a tool or pliers (see "Replacing the valve stem seals of the Lada Prior").

40. Clean carbon deposits from the valve with a suitable tool (eg a wire brush). Then carefully inspect the valve.

41. Replace valves with the following defects: deep marks and scratches on the working chamfer 1, cracks, deformation of the rod 3, warping of the plate 2, traces of burnout. Small marks and scratches on the working chamfer can be removed by lapping the valves (see Lapping the valves).

42. If the damage to the working chamfer of the valves cannot be removed by lapping, you can grind the chamfer on a special machine in a specialized workshop.

43. Check the condition of the valve seats. The working chamfers of the seats should be free of signs of wear, cavities, corrosion, etc. The valve seats can be replaced by a specialist workshop. Minor damages (minor risks, scratches, etc.) can be removed by lapping the valves (see Lapping the valves of the Lada Prior).

44. More significant defects in valve seats are eliminated by grinding. It is recommended to grind the saddles in a specialized workshop.

• Valve seat chamfer machining points

45. Having locksmith skills, this work can be done manually using a set of special cutters. First, a chamfer a is processed at an angle of 15 °, then a chamfer b at an angle of 20 ° and a chamfer c at an angle of 45 °. After grinding, the valves must be lapped (see Lapping the valves).

46. ​​Check the condition of the valve springs. Replace bent, broken or cracked springs.

• Valve spring test parameters

47. To check the elasticity of the outer spring, measure its free height and then under two different loads. If the spring is out of specification, replace it.

48. Inspect the Lada Prior valve hydraulic pushers. If the working surface 1 has scuffs, scratches and other defects, replace the hydraulic pushers. Measure the outer diameters of the pushers, replace the worn pushers. On the working surfaces 2 there should be no scoring, nicks, scratches, traces of stepped or uneven wear, metal rubbing. Hydraulic pushers with such defects must be replaced. On surfaces 2, concentric running-in marks with camshaft cams are allowed.

• Dimensions of valves and their guides

49. Check the clearances between the guide bushings and the valves. The gap is calculated as the difference between the diameter of the hole in the sleeve and the diameter of the valve stem of the Lada Prior. It is recommended to check the clearance in a specialized workshop, since a special tool (internal gauge) is needed to measure the diameter of the bushings.

• Clearances between the valve and the guide sleeve, mm:

rated for intake and exhaust valves. 0.018-0.047

maximum permissible for inlet and outlet valves. 0.300

50. If the clearance has not reached the maximum allowable, you can try to eliminate it by replacing the valve. If this cannot be done or the clearance exceeds the maximum allowable, replace the guide bush. To do this, press out the defective bushing from the side of the combustion chamber with a special mandrel, having previously measured the height of the protrusion of the upper part of the bushing above the surface of the block head.

51. Cool the new bushing (for example, using a carbon dioxide fire extinguisher), lubricate it with engine oil, insert it into a special mandrel and press it in from the side of the camshaft so that the protrusion of the top of the bushing corresponds to the measured value. Reamer the bore in the bushing using a reamer to 7,000-7,015 mm for inlet and outlet valves.

• 52. If you are installing an old valve, remove burrs from the grooves for crackers.After that, it is necessary to grind the valve to the seat (see "Lapping the valves").
• 53. Install the valves in the block head in accordance with the previously made markings, having previously lubricated the rods with engine oil.
• 54. Install the valve stem seals (see "Replacing the valve stem seals").
• 55. Install the camshafts and the camshaft bearing housing (see "Replacing the valve stem seals").
• 56. Install on the block head all the parts and assemblies removed during disassembly.

Often, when overhauling an engine, removal, disassembly and assembly of the cylinder head is required. The article discusses how to remove the head on the Lada Priora 16 valves. Also attached is a video with a detailed video report on the assembly and disassembly of the cylinder head.

The cylinder head is one of the main engine components. It consists of a cover that serves to protect the internal parts from external environmental influences. The cylinder head is made by spot casting from cast iron or aluminum alloy. To remove the residual stress that occurs during the casting phase, the product is artificially aged by mechanical processing.

The lower part of the cylinder head is more extended, thus, it protects the inside of the block more reliably. The inside of the head surface is perfectly smooth. The unit consists of a large number of elements.

In the upper part of the cylinder head, space is reserved for the camshaft bearing housings, valve springs, bushings and support washers, as well as for the gas distribution mechanism. Since the head consists of a large number of parts, the process of assembling and disassembling the cylinder head is very laborious. In the aggregate, the parts of the unit convert energy during the combustion of fuel into mechanical energy, thanks to which the car moves.

When operating a car, you should constantly monitor the tight fit of the cylinder head to the block itself, so that there are no leaks of working fluids. Like all units of a car, the cylinder head requires regular maintenance. Details that are under constant stress require more attention. These include the components of the gas distribution mechanism: valve seals, valves, camshaft oil seals, gasket. The service life of its components and assemblies depends on the quality of car maintenance.

Replacement of consumables should be performed according to the recommendations specified in the Lada Priora service manual. The oil seals and the gasket should be changed as they wear out or when they are externally damaged. There are a number of operations in which it is necessary to dismantle the cylinder head: rework and grinding of seats, replacement of valves, pressure testing of valve seats and bushings, and others.

The cylinder head on the Lada Priore 16 cylinders must be replaced if, upon visual inspection, chips, cracks, signs of corrosion are found. During the repair, the following work can be performed:

• change gaskets;
• replacement of camshafts;
• change hydraulic lifters if they are faulty;
• bent valves change if the timing belt breaks.

Removal, disassembly and assembly of the cylinder head for repair and revision consists of the following steps:

1. First of all, it is necessary to cool the engine, relieve pressure in the fuel system.
2. To de-energize the car, you need to disconnect the negative terminal from the storage battery.
3. Before removing the unit, the coolant must be drained.
4. Next, we dismantle the cylinder head and install it so as not to damage the valve for further repair and revision.
5. Having unscrewed the fastening nuts, we dismantle the support of the power unit.
6. Next, we sequentially remove the fuel pipe bracket, phase sensors, coolant temperature, emergency oil pressure warning light, temperature gauge.
7. Then remove the thermostat with the gasket installed under it.
8. Remove spark plugs to avoid damage.
9. Next, remove the camshaft bearing housing.
10. At the next stage, the camshafts and oil seals, put on their front ends, are removed.

Removed camshafts

Remove the hydraulic pushers from the holes in the cylinder head.

Now carbon deposits are removed from the combustion chambers.

Next, you need to inspect the unit. If cracks, scratches, chips, traces of burnout in the combustion chambers are found on it, then it must be replaced.

Remove burrs and nicks from the surface of the unit.

Next, using the feeler gauges and a ruler, you should check the evenness of the surfaces for the intake manifold and the manifold.

Now you need to check the tightness of the cylinder head.

Then we check the surfaces on which the camshaft journals rest, as well as the bearing housing. If there are any defects, it should be replaced.

Then we flush the oil channels and check the tightness.

The next step is to remove the valves. If there are scratches on the valves, deformation of the rod or plate, traces of burnout, they must be replaced.

Valve suitability check

Next, remove the valve stem seals and, if necessary, replace them.

It is necessary to check the condition of the seats. If necessary, they are revised.

Significant valve defects are eliminated by reworking and grinding. Then the valves are lapped.

Next, you need to check the condition of the valve springs, their elasticity. Replace if necessary.

After checking all components and revision, the valves must be inserted into the cylinder head at the previously marked places, lubricating the rods with engine oil.

The valve stem seals, camshafts and bearing housing are then installed.

Next, we install the cylinder head in place.

When installing the head, be sure to replace the gasket. The fastening bolts should be tightened according to the moment specified in the manual for the Lada Priora car.

Bolt Tightening Sequence

After installing the block head, all components and assemblies that were dismantled to remove it are installed in the reverse order.

Repair of the unit in question takes a long time, but it is quite feasible on our own. If you carry out a technical inspection, repair Lada Priora on time and change the necessary consumables, then this will shed the life of the car.

This video tells about the repair of the Lada Priora cylinder head.

Cars of the VAZ-2112 family were produced with one of two 16-valve engines - 21124 and 21120. The working volume of these engines is different, and only one part called "cylinder head" is used - it is designated by the numbers 2112-1003011. It is rumored that the cylinder head from the 21120 engine does not fit the 24th engine, but a reverse replacement is possible. However, there is only one SKU in the parts catalog, and it fits two motors at once. Further, it is considered what actions to repair the VAZ-2112 cylinder head can be performed by ourselves. We will only talk about 16-valve valves.

An example of dismantling is shown in the video. We look.

First of all, to get to the cylinder head, you need to remove the cylinder head cover. For different 16-valve valves, this operation is different, and the article numbers for the cover also look different: 2112-1003260 (-10) and 21124-1003260.

Cover from the internal combustion engine VAZ-21124 (1.6 l)

The timing belt will also need to be removed - there are no differences between different engines.

Consider how you can detach the exhaust manifold from the cylinder head. On engine 21120:

Remove the exhaust pipe of the muffler: unscrew two nuts 1 (key "13"), remove the clamping bar, unscrew six nuts 2 (key "14") and dismantle, not forgetting to turn off the oxygen sensor. The photo shows three nuts out of six.

Everything important is under the screen

Now we will talk about the 21124 engine:

1. We turn off both oxygen sensors. We unscrew the three nuts securing the protective screen (key "10") and disassemble the bracket by unscrewing the four nuts with the key "13".

How to disassemble the mounting bracket

Operation with additional silencer

Here we considered that the VUT hose was disconnected from the intake module. In the final, on any of the engines, the candles are unscrewed (pipe wrench "16").

The tightening torques for the fastening screws are given in a different text.In general, on VAZ-2112 hatchbacks, cylinder head repairs begin by replacing the "elongated" screws with new ones. The length must be 95 mm or less.

The procedure for loosening (left) and tightening the fastening screws

Taking a wide steel ruler, they check:

Measurements are taken along each of the diagonals. Use a set of probes.

To remove any valve, you will need to remove the camshaft. All screws on the bearing housing must be unscrewed evenly, and tightened with a force of 10 N * m. The hydraulic compensator can be removed with a magnet, and then the valve is dried by compressing the spring with a puller (see photo).

Carbon deposits may be present in the valve passages. It is cleaned off:

• Flat screwdriver;
• Sanding felt.

Lapping is carried out as follows: a rubber pipe is put on the valve, a paste with diamond chips is applied (one drop), then the valve is pressed into the channel and scrolled. It will be possible to change the valve stem seals (2112-1007026). You can't do without a special puller.

On any car, including the VAZ-2112, cylinder head repair is reduced to cleaning and checking, as well as correcting geometry defects. In the latter case, we are talking about milling. The presence of cracks and chips is a reason for replacement, not for repair.

The burned-out valve can be seen immediately.

One valve in cylinder 2 burned out

Carbon deposits were found in each valve channel.

Carbon deposits in the cylinder head channels

Repair: cleaning all channels, replacing the valve with lapping.
The direct implementation of the repair of the VAZ 2112 cylinder head will require several operations in which some special equipment is needed. Of course, at home there is no such possibility, and motorists simply replace worn out parts. Next, we will consider the process of repairing the block head, as well as some of the nuances associated with this work.

Before proceeding directly to the cylinder head repair process, it is worth noting that the head must be completely disassembled and all the necessary spare parts purchased. Consider the process of a complete overhaul of the cylinder head.

The process of washing car spare parts with hot kerosene

In order to wash the head, it must be completely disassembled, that is, all parts that can be easily removed are dismantled. A full wash requires 12 liters of hot kerosene. In car services, this is done using a spray that delivers fluid under pressure. So, all the dirt and remnants of metal shavings are washed off. Washing is carried out until the cylinder head is completely clean.

Cylinder head crimping process

Crimping is a process by which the integrity of a part is checked. Crimping can be done in two ways, which are similar in principle. The first is to close all the cracks and fill the part with water. There is, somewhere water comes through or flows, then the integrity is broken and repairs are needed. The second method is to close all the cracks and the head is immersed in an aqueous solution. It will immediately be seen where the depressurization of the part takes place. If the integrity of the head is damaged, then it is necessary to restore it.

The valve seats must be removed before continuing with the rest of the overhaul. In the best case, they will easily knock out of the seat, and if not, then you will have to use Russian ingenuity.

The valve is welded to the seat and knocked out of the seat

So what if the valve seats aren't knocked out? The solution is simple. It is necessary to weld a tube to them so that the working end passes through the channel of the guide sleeve and knocks out until the saddle comes off the seat mount. Of course, cracks can form on the seat ring of the saddle or a piece break off. After completing the procedure, it is necessary to inspect the place and, if necessary, weld with argon welding.

Often, repairing the cylinder head is not complete without checking the plane. This can be done by contacting a car service that has a test stand, or by asking a neighbor in the garage for a special ruler for measuring the plane of the cylinder head.

Measurement of the cylinder head plane for deformation using a metal ruler and a probe

Important! It is recommended to give such block heads to a car service with the proper equipment, since only there they will be able to measure the plane and grind it to the desired size.

So, if there is a deformation on the block head or the plane has a deflection, then it must be sanded. This operation is done on a special surface grinding machine. Usually, the auto repairman is advised not to remove more than 10 mm of thickness. Consider the possible options for grinding the cylinder head by dimension:

• Repair 1 - 1-2.5 mm;
• Repair 2 - 2.5-5 mm;
• Repair 3 - 5-7.5 mm;
• Repair 4 - 10 mm - the maximum allowable value for grinding GBU VAZ 2112.

Cylinder head surface grinding process

Note! If you remove the thickness of the plane more than 10 mm, then this can lead to incorrect operation of the timing mechanism, loss of power and an increase in fuel consumption.

Argon welding is welding work that is carried out on aluminum. For this, a special gas is used - argon. So, to eliminate cracks and weld defects in the seats of the valve seats, it is required to weld them, and then carry out milling work on special equipment.

The process of repairing cracks in the cylinder head using argon welding

After the welding and milling work has been carried out, it is necessary to bring the surface to readiness. For this, the cylinder head is placed on a special stand, where the surface is polished using a special paste produced by ABRO or its analogues. This is necessary so that the surface does not have roughness. When this procedure is completed, it is necessary to once again wash the part from metal chips and residues of working material.

It is best to assemble the cylinder head at a special stand.

When the block head is processed and washed, you can proceed directly to its assembly. But, before that you need to carry out preparatory work. Let's consider all the stages of the assembly sequentially:

1. The cylinder head housing is installed in a special heating furnace.
2. In the meantime, measurements of the valve seat to the seat are taken, the guide bushings are unfolded.
3. When the cylinder head is hot, it is taken out of the oven. On hot, the valve seats are installed.

On a special stand, the valve chamfer is processed

Valve seat shrinkage process steps

Valve Lapping Process

Thus, a major overhaul of the cylinder head of a 16-valve VAZ 2112 engine is being carried out. This process will take 1-2 days at a car service, but a motorist can spend much more time in his garage, since the lack of a tool will affect. So, it is recommended to repair the cylinder head at car services, where everything will be done much faster and better. Of course, this will hit the pocket, since a high-quality and overhaul of this part will cost on average about 7,000-10,000 rubles. together with spare parts.