Re-broaching the cylinder head. Re-broaching the cylinder head Tightening torques zmz 405 euro 2

And we wrap the bolts of its fastening (tightening torque 25-40 Nm).
We tighten the bolt of the oil pump bracket to a torque of 7-10 Nm.

Turning the crankshaft, set the crankshaft sprocket mark opposite the cylinder block alignment mark.
Assembling the oil pump drive
(see "Dismantling the oil pump drive"), covering engine oil drive gears, intermediate shaft bushings and the shaft itself. Installing the lower chain damper Before installing, dip both chains in engine oil.

ATTENTION
When installing the sprocket of the lower chain tensioner, make sure that the marks on the sprockets of the crankshaft and countershaft coincide with the corresponding marks on the cylinder block (see "Dismantling the timing mechanism").

We change the seal in the front cover of the cylinder block (see "Replacing the front crankshaft oil seal") and install the cover with a new gasket and generator bracket.
Install the lower chain hydraulic tensioner (see "Removing and installing hydraulic tensioners").
We tighten and tie the upper timing chain to the generator bracket. We apply silicone sealant to the cylinder block mating plane (for attaching the oil pan), to the joints of the front and rear covers with the cylinder block.
Install the oil pan (tightening torque of the oil pan mounting bolts 12-18 Nm, and the nuts 11-16 Nm).
Install the clutch crankcase amplifier. We put a pulley on the toe of the crankshaft and tighten the ratchet bolt to a torque of 104-128 Nm.
Install the cylinder head (see "Removing and repairing the cylinder head").
Install discs and clutch housing (see "Replacing the driven and driving discs").
Install the starter (see "Removing the starter").
We install the coolant pump (see "Replacing the coolant pump"), the generator (see "Removing the generator"), the tensioner roller with the tensioner (see "Replacing the tensioner roller of the accessory drive belt"). *
Further assembly of the ZMZ 406 engine is carried out in the reverse sequence to disassembly.

Scheme of installation and stamping of covers camshafts

SEQUENCING

We remove the tips from the spark plugs along with the high-voltage wires.

Remove the ignition coils (see Checking and replacing the ignition coils). The coils can be left on the cover by disconnecting the low voltage wires from them.
Disconnect the throttle and air valve drive cables from the carburetor (see Removing the carburetor).
Remove the grille and upper grille panel (see Removing the grille and Removing the upper grille panel).
We disconnect the wires from the oil temperature and pressure sensors (see Replacing the temperature gauge sensors, Replacing the oil pressure sensors), bend the wire fastening brackets ...

… And remove the wires from the engine.

We loosen the clamp and disconnect the small hose of the crankcase ventilation system.

Using the "12" wrench, unscrew the eight bolts of the block head cover.

Remove the cover.

Turning the crankshaft with the head "36", we set it to the TDC position of the compression stroke of the first cylinder, (the risk on the crankshaft pulley must coincide with the protrusion on the front cover of the cylinder block, ...

... and the marks on the camshaft sprockets must be turned in opposite directions and be in line with the upper edge of the cylinder head.

ATTENTION
Do not turn the crankshaft during further work.

For convenience, we remove the fuel pump (see Removing the fuel pump of the ZMZ-4063 engine) and, without disconnecting the hoses, take it to the side (you can leave the fuel pump on the cover).

Using the 12 key, unscrew the four bolts (the two lower ones are short).

Remove the front cover of the cylinder head ...

And a gasket.

Using a 6-point hex wrench, unscrew the two screws ...

… And remove the upper damper of the upper chain.

With the same key, unscrew the two screws securing the middle damper.

We loosen the chain tension in the area near the middle damper by turning the exhaust valve shaft clockwise with a "17" wrench for the sprocket mounting bolt (or with a "30" wrench for a square on the shaft).

We remove the middle soot.

Holding the exhaust valve shaft with a "30" wrench, unscrew the sprocket mounting bolt with a "17" wrench.

Remove the sprocket from the exhaust valve shaft.

Similarly, we unscrew the bolt securing the intake valve shaft sprocket.

Remove the eccentric of the fuel pump drive ...

… And an intake sprocket.

Using the "12" head, unscrew the four bolts securing the front camshaft cover.

Removing the front cover ...

... and plastic inserts for limiting the axial movement of the camshafts.

Using the "12" head, sequentially, half a turn, loosen the tightening of the camshaft cap bolts until the valve springs stop pressing the shafts.

Finally, we unscrew the bolts and remove the covers.

We remove the camshaft.

Remove the second camshaft in the same way.
Before installing the camshafts, lubricate their bearing journals, cams, as well as beds in the head and covers with engine oil.

Install the exhaust valve shaft with the pin to the right (looking from the front), and the intake valve shaft with the pin up. In this case, the shafts are in a stable position (for clarity, the radiator hose has been removed).

The intake and exhaust camshafts are interchangeable, but ...

ATTENTION
pay attention to correct position pins in the holes in the camshaft flanges.

We install each cover in its place, according to the serial number stamped on it.

We orient the covers so that the number embossed on them is facing the outside of the head.

We tighten the cover fastening bolts with a torque of 1.9-2.3 kgf.m, after which ...

… We turn the intake valve shaft so that its pin is located opposite the upper edge of the block head.

We install sprockets with a chain on the shafts, starting from the exhaust camshaft.

With a tensioned branch of the chain on the side of the middle damper, the mark on the sprocket should be located opposite the upper edge of the block head.

We put the middle damper in place and put the second asterisk.
We carry out further assembly in the reverse order of disassembly.

ATTENTION
After installing the hydraulic tensioner ...

We check the coincidence of all marks on the crankshaft pulley and sprockets. Otherwise, remove the incorrectly installed sprocket and, by moving it to one section of the chain, reinstall it.

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15. Disconnect plug strips 1 from injectors.

Unbend holders 2 of the wiring harness and remove the harness from the holders.

Move wiring harness away from engine.

Then disconnect the front exhaust pipe from the exhaust manifold, disconnect the hose from the body throttle, remove the radiator inlet pipe, remove the generator.

1. Remove the camshafts.

2. Loosen the tightening of the clamps 1 and remove the hoses 2 and 3 from the throttle body fittings.

3. Remove the thermostat with the housing.

4. Remove the spark plugs.

5. Remove the bolts 1 securing the block head. Remove bolts 1 and washers.

6. Remove the cylinder head and the head gasket.

Do not drive screwdrivers or any other tool between the block head and the cylinder block, as this could damage the surface of the cylinder head adjacent to the cylinder block.

Installation

Install the block head in the reverse order of removal.

The order of tightening the bolts securing the head of the block is shown in the figure.

Tighten the bolts of the block head in two stages:

1st stage - 40-60 Nm (4.0-6.0 kgf · m);

2nd stage - 130-145 Nm (13.0-14.5 kgf · m).

As we have already found out, the cylinder head is one of the most important engine components. If you feel confident and have the skills to use a locksmith tool, then broaching the cylinder head will not be difficult. It remains to decide for what and how to draw the cylinder head.

When you need a cylinder head broach

Maybe not all car enthusiasts know, but modern cars do not need preventive broaching of the cylinder head.

Previously, broaching the cylinder head was a mandatory item of the first maintenance, then the situation changed. Even relatively modern VAZ engines... Cylinder head broaching is mainly required today for old models of VAZ, UAZ, Moskvich, etc. engines.

The main reason that prompts the owner of the car to think about the need to broach the cylinder head is "sputum" at the junction of the head and the block. This indicates an existing oil leak.

There may be several reasons. The most traditional: failure, warpage of the cylinder head as a result of engine overheating unnoticed by you, or initially incorrectly tightened cylinder head bolts. If you got a "kapitalka" at a car service.

How to pull the cylinder head bolts

From the study. It is from the study of the Manual for the repair of your car, preferably the original one. It is there that the manufacturer indicates everything that is needed to tighten the cylinder head. And you need to know:

• the order (diagram) of tightening the cylinder head bolts;
• what torque is required;
• what bolts are used to tighten the cylinder head.

Bolts for tightening the cylinder head are a special conversation. The point is that in modern engines bolts with special characteristics are used for the cylinder head. The so-called "spring" bolts, which, due to their properties after the initial pulling at the factory, do not need additional.

Moreover, when trying to pull the cylinder head bolts, due to the "fluidity" of the metal, they will stretch. As a result, you can get a break in the bolt.

During cylinder head repair you need to put gaskets that do not shrink. This eliminates the need to pull the cylinder head bolts.

But, if you have already decided that broaching the cylinder head bolts is extremely necessary for you, then it should be done with the "manual" from the manufacturer and with the help of a torque wrench. Motion in motion, digit to digit. Amateur performance on the basis of "reserve" is not needed here.

Cylinder head tightening control

To keep your soul calm, and as soon as you decide to broach the head bolts, there is a method for controlling the tightening torque of the cylinder head bolts. Naturally with a torque wrench.

A moment is applied to the bolt, equal to the moment of the bolt breaking away. After the start of the turn, you need to control the moment of starting. If it has not increased, then everything is in order, the bolt began to stretch.

If the moment starts to rise, it means that the bolt has not reached the yield point. Here you need to tighten cylinder head bolt until the tightening torque stabilizes.

When checking the tightening of the cylinder head bolts, pay attention to two things. If a torque of 20 kgGcm is applied to the bolt, but the yield point has not been reached, then the bolt must be replaced, since it has increased strength.

If, at the moment of tightening the bolt, you see that the moment decreases, then this means the destruction of the bolt, and it definitely requires replacement.

Such requirements for the cylinder head bolts can be easily explained: they work in a constant heating - cooling mode.

Good luck, and may the do-it-yourself tightening of the cylinder head bolts go well.

Hello again :) However, I am often asked, “do I need to re-broach the cylinder head?”. There are many who believe that they put the head on, tightened it and do not touch it anymore.

In the process of my rather long work as a minder, and this is already more than a quarter of a century, I was convinced from my own experience that if you are too lazy to stretch the head through the time set for pulling it, then after a while, and this largely depends on the driving style driver and distance traveled at the same time, you will have to shoot.

Usually the gasket burns out within a year, and if a person travels a long distance, then in a month. Therefore, my advice is this: you cannot go far with the head not extended, otherwise you will have to take it off on the road. But you know, I noticed that if the equipment came directly from the factory, then after the mileage set for broaching, the heads rarely weaken. It is possible that the material of the gasket, which is put there, is different.

So how long does it take to pull the cylinder head? On average, after a thousand km. mileage. This is written in the instructions and this is confirmed by practice. In the instructions for so. it is also written that after ten thousand it is necessary to stretch again or check the broaching of the head.

Well, in most cases, one broach was enough. But rarely, of course, but there were cases that when the gasket burned out, the head was weak even after one broach. In my opinion it all depends on the material cylinder head gaskets Which shrinks strongly, and which does not sag at all.

The physics of this phenomenon, namely the weakening of the head broach, is obvious. Typically, the cylinder heads are aluminum, and the bolts or studs are still steel. When aluminum is heated, the expansion coefficient is greater than that of steel, and when the engine heats up, the head expands and squeezes the gasket like a press, and when it cools down, it also releases the gasket, and the bolts are esessno loosened.

There is a rule: you cannot stretch hot engine, only cold. I will tell you a list of engines that you need to stretch from my experience with which I dealt, namely: zmz405,406,409. engines Zmz-402, UAZ 417.421. Zmz engines 511,512,523, zil-130, Ural.

I will not say about others, but usually VAZ heads rarely sink. I can’t say anything about foreign cars either, because I’ve been looking at them a little, and I don’t want to fucking be. That's all for now.

So what is our conclusion? But to what! stretch out the heads in time! And then the gaskets will burn to hujam!

There is more to come. In order not to suffer with the re-broaching of the head, you have to disassemble almost half of the engine in order to make sure that it does not weaken, but otherwise it happens. Depends on the gasket material. You can't guess right away.

In order not to re-stretch the heads, you can put a metal package. About that, you can read. And although I wrote about the UAZ-patriot, this may apply to many engines. Good luck friends!