In detail: vaz 2112 do-it-yourself engine overhaul from a real master for the site my.housecope.com.
One of our old customers changed the car for a VAZ 21124 (1.6 liter engine, 16 valve). The car is not new, the mileage on the odometer is 85 thousand km. After some time, problems appeared - immediately large quantities of antifreeze left the cooling system, the expansion tank was inflated, the client had to constantly top up the antifreeze. After a trip to the intercity, the car was brought in for repairs - the oil pressure lamp blinks, hydraulic lifters knock. After inspecting the car, a verdict was delivered - the mileage was twisted, but the car was in good condition. Compression measurement showed a difference in cylinders up to 2 atmospheres. We will disassemble the engine, search for and eliminate the causes of the problems.
We remove the attachments, then the valve cover and the camshaft bed. The hydraulic lifters turned a little blue from oil starvation, but the client was lucky - the camshaft necks and beds in the cylinder head are in good condition - here expensive repairs can be avoided.
We remove the cylinder head - this is the reason for the escaping antifreeze - a burned-out gasket. Judging by the rust, the previous owner did not want to repair the engine and filled in water, so he sold the car. The plane of the head requires milling.
The cylinders are still in very good condition, the factory hon is visible. Water entered the second cylinder through the gasket, and traces of rust are visible on the surface of the cylinder. However, the water here has not yet had time to cause wear on the surface of the cylinder - if the client had traveled on the water for a longer time, there would have been no trace of honing.
The catalyst is sentenced to be replaced - the gas joint studs have stuck tightly, but the main reason for the replacement is that the insides of the catalyst are sintered and crumbled.
Video (click to play).
We dismantle the cylinder block from the car - without its complex bulkhead and troubleshooting - further assembly and starting of the engine will be like a tape measure.
We completely disassemble the block. All crankshaft journals are measured with a micrometer - journals without wear, at the upper tolerance limit. But the inserts, especially the root ones on the last neck, have traces of oil starvation. A little more - and the insert could turn. The seating plane of the block, which has extensive areas of corrosion, was milled.
Since there was no talk of tuning the engine (the client asked for a standard overhaul), they did not install the ShPG from Priora. Since the cylinders are in good condition, they limited themselves to replacing the pistons (group B was in the engine), they put group C. The connecting rods remained native, 2110. The piston rings were replaced with type-setting ones, Kolbenschmidt. Such a replacement will still add a few horsepower to the motor, by reducing mechanical friction losses. All parts were washed. The oil pump was opened and the gears, body and parts of the pressure reducing valve were carefully examined - no defects were found. The crankshaft liners and persistent half rings were replaced with new ones, the crankshaft remained in the nominal size. Updated all oil seals and gaskets. They installed a new pump - the factory one. The flywheel is still in excellent condition, the clutch is also - the previous owner changed it to Kraft. We limited ourselves to replacing the release bearing with a VAZ one (the Kraft release bearing has a weak point - a plastic inner sleeve, which often crumbles).
It's time to take care of the head. It was completely disassembled by drying the valve. The mating plane has suffered from water and rust, traces of the gasket burnout are visible.
Outlet guides are worn out - valves are loose. The valves themselves are in good condition - we grind the working chamfers on a special machine, thereby the client saves on new valves.We repress the exhaust bushings with new ones. The valve stem seals have turned into croutons, they are also replaced with new ones - GOETZE. The head is washed, the plane is milled, the chamfers of the seats are machined on the AZ VV80 machine - the cutter creates three chamfers at the same time, after which lapping is not required. The valves simply dry out.
We update the timing belt and rollers - put the kit PowerGrip (GATES)... We put the cylinder head gasket from the Priora. Oil filter - MANN. The catalyst is replaced with a 4-1 stainless steel "spider". It is put in place. It was not possible to find an intermediate pipe from the catalyst to the resonator on sale - I had to cut off the stuck catalyst studs and use the old pipe. The gas joint (with a new gasket) is connected with hardened bolts with copper nuts and grovers. We also update the round graphite ring in the next gas joint, along with bolts and springs.
We glue the camshaft bed and the valve cover on the anaerobic sealant Loctite (silicone sealants cannot be used!), We update the candles - install NGK. New hydraulic pushers were supplied - INA. We fill in oil with Lukoil Lux 10W40.
So, everything is assembled, we start the engine. The pressure lamp goes out, the wetsuits fill with oil and die down. The motor runs smoothly.
After an hour of idling, the car is handed over to the client.
The results of the overhaul are summarized in standard estimates, which can be found in the Price List section.
Posted on August 27, 2012 The author of the article, photo-video materials:
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:
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 landing 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.
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:
The cylinder head housing is installed in a special heating furnace.
In the meantime, measurements of the valve seat to the seat are taken, the guide bushings are unfolded.
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.
