Stand for repairing cylinder heads with their own hands evgeniya travnikova

High requirements for the accuracy of machining cylinder head elements in repair practice dictate the need to use specialized equipment.

Equipment for the repair of cylinder heads is produced by many companies, but not all samples of machine tools and tools are successfully used in practice. Our range of machine tools and tools consists only of the best models in their segment and meets all modern requirements.

Good afternoon. Starting this article, I will explain a little what will be discussed. It will be not only about special tools with which you can repair the cylinder head, but also about how to work with this tool correctly. It turns out that not everyone knows how to properly use a special tool and this sometimes leads to irreparable consequences. I will try to describe in detail the entire process of work so that you can independently do all the work on repairing the cylinder head.

So, let's begin. In principle, the whole process is practically the same, in the classics, in Samara and subsequent models. The first thing we have to deal with is the removal of the springs and valves (drying out of the valve). For this, a special puller is used.

Of course, there are many different devices, but this is the most pervasive. This is what we will consider. The puller is attached with the front part to the pin, and a special grip is installed on the spring plate.

Now we need a special substrate in the combustion chamber for the valve. Why is it needed? When you press the lever of the device, the valve will go down, and it will go through the appropriate path until it rests on its plate, for example, on the table on which you take the head. At this time, the spring will compress and prevent the crackers from being pulled out. This backing can be a piece of rubber of the right thickness or a block of wood.

Pressing on the lever, the valve rests against the substrate, and you can easily remove the crackers.

Put all the crackers neatly in a box, because then it is very difficult to look for the lost crackers.

There is, of course, a barbaric way of extracting rusks. It is worth resorting to it only in special cases when there is no special puller. This process is carried out with a hammer and a piece of metal pipe (a candle wrench works well here).

After striking, do not immediately remove the hammer, otherwise the crackers will fly apart. You can shove a piece of rags into the upper part of the tube, this will delay the flying out crackers.

The next tool we need is a valve guide puller. I wrote the process of replacing the valve guides in the article (Replacing the valve guides). There are different pullers. First (percussion).

Why shock? But because the pressing takes place by hitting the mandrel with a hammer. This method does not always go smoothly. There were cases when the mandrel went into a skew and removed a little metal from the bushing seating plane, thereby decreasing its seating density, which is not good in our case.

A widespread tool has become a screw smooth press-on puller.

This puller allows the bushing to be replaced smoothly and safely. They are sold in auto stores, but you can make it yourself, and I will definitely post it as I draw a drawing.

We also need a tool for removing and installing the valve oil seal. Care must be taken when removing and installing oil seals.Why careful? Because the side on which the oil seal is installed is very fragile and can be damaged.

For dismantling, special clamps are used, by the way, this clamp can be made by yourself. I saw a craftsman make a clamp from a sawn nut in half and welded to a round nose pliers.

The extraction method is simple. Cover the removable oil seal and rotate the grip strictly vertically along the axis in one direction and the other, while stretching upwards. It is strictly forbidden to loosen the oil seal to the sides, because there is a danger of damaging the side of the guide sleeve and the guide will need to be changed.

Installation of oil seals (caps) is done in a special mandrel.

Before installing the oil seals, check them for tightness. Try to put it on the rim of the sleeve with your hands. If it does not find it, then this is our oil seal and can be installed. If the oil seal is loose or loose, then it will leak oil and will not cope with its task.

Next, we need a tool such as a sweep.

I recommend using these reamers, because they have a guide for accurate entry into the hole. We need a reamer with a diameter of 8.00 mm. Deployment is as follows. Install the reamer into the just pressed-in guide sleeve and lightly press it until it comes out on the other side.

The next step will be lapping the valves. Before grinding the valves, they need to be processed with cones.

It is better to use such cutters. We need three cutters with different cutting angles. The first is 45 degrees, the second is 60 and the third is 30. They handle the valve seat with ease and effortlessness.

After the saddles have been processed with cones, they need to be ground in. What tool is used to grind the valves, I recommend reading the article (Tool for grinding valves).

Perhaps this is all from a special tool, then everything can be done with the help of keys and screwdrivers.

At the moment this is all, and if something else appears, I will definitely add it.

The main thing to look out for is an inappropriate / inaccurate connection between the manifold valves and the cylinder head. The appearance of the slightest irregularities or steps can lead to undesirable consequences that begin to slow down the movement, partially blocking the channel and therefore must be removed. After removing areas with obvious inconsistencies, the manifold gaskets need to be modified, as they can also be an obstruction to the flow.

It is also necessary to fit the manifold onto the pins. This is extremely important for the reason that the fasteners holding the manifolds can stretch and as a result there is a slight change in the cylinder head planes relative to the manifold. If this is not done, then all the work to prevent inconsistencies will be useless.

I want to note that two pins must be placed on the collector (at the edges).

Before connecting the cylinder head and the manifold, you need to make a hole using cutters to refine the cylinder head. Then we put the pin on the head and put the collector on it. It is important that the second one sat down freely, but there should be no backlash. You can then ensure that the two elements are positioned accurately with great confidence. You also need to make some holes in the gasket. This is how optimal docking should be done.

The revision of the cylinder head also provides for the need to refine the channels, since a deformed shape, metal under the bushings, etc. can be observed in them. The channels are reworked by means of a ball cutter. It is better when you have more than one cutter, but several and with different parameters (sizes and shapes). Working with a milling cutter, you can achieve the removal of any irregularities, as well as increase the passable section.

It is extremely important to ensure that the channel bend is as smooth as possible and the corresponding curvature dimensions are observed. The surface on the intake ducts should be slightly rough - this contributes to good evaporation of gasoline from its walls. The outlet channel can be polished to a high shine. The channel section should not have a round shape, it has a slightly elliptical shape.
When performing an increase in the channels, it is important not to overdo it, you need to know the measure, since there is a possibility of touching the cooling channel or the oil channel. The cylinder head on classic engines allows you to increase and expand the channels, while on 8-valve VAZ engines, problems are inevitable.

Before you directly engage in the boring of channels, you should find out where to start this process - from a collector or a gas cylinder head. If you need to significantly increase the diameter of the valves, then it is better to start from the area where their walls are thinner. This will reduce the risk of accidental opening of the channels the next time you align. The parts of the bushings that protrude into the channels also need to be modified so that they do not interfere.

As a rule, they need to be either shortened or sharpened. There are situations when the bushings are grinded against the valve wall. Some motorists consider this method to be the best in terms of benefits, although, in practice, rarely does anyone do this, since it significantly reduces the resource of the guides. Correct modification of the valves is possible only under two conditions: experience and following the instructions.

Valve redesign is to reduce weight and increase flow. To lighten the valve, it must be reground or reground. Excess metal will then be removed from both sides. The valve stem is also being reworked - it needs to be narrowed. You can also choose the option without replacing the bushings, in which case you need to make the leg thinner all the way from the guide bush to the plate. A special result can be achieved by reducing the diameter of the stem. For example, reducing the leg from eight mm to seven helps to reduce the mass of the rod itself by 20%, increases the throughput (this is in 8-valve motors).

In reality, the valves are made of an alloy of titanium and aluminum and therefore have amazing lightness, which is combined with some unpleasant moments: high cost and fragility. Given this fragility, strong recommendations are made for valve springs and valve seats. The springs can be left at the factory or slightly loosened. It is advisable to change the saddles to others made of bronze.

The revision of the cylinder head also implies a change in the shape of the combustion chamber. In this case, three areas of work can be distinguished:

1. Reduced knock
2. Improvement for cylinder filling
3. Fulfillment of the conditions for optimal distribution of the mixture in the combustion chamber.

Detonation puts a heavy load on pistons and rings. It can be determined by the level of metallic sounds that propagate through the car engine. The sources of this phenomenon can be the most distant parts of the combustion chamber from the spark plug. It is solved like this:
· It is necessary to reduce to a minimum the work in the combustion chamber, which increases the spread of combustion.
· The number of compressor stations should be minimized. These areas include camera corners and sharp edges. To do this, you need to smooth the surface as carefully as possible.

The last two executions to improve the shape of the combustion chamber are very difficult to do on your own, since you need to have excellent knowledge in the field of physics.

The revision of the cylinder head is not quite complicated at some stages and is a fully justified procedure. Correct modification will increase the power of your vehicle's engine.

In the video, the auto mechanic talks about the nuances of the correct boring of channels in the manifold for the modified head.

Let's start by defining the concepts. The cylinder block of a modern car is the basis of the engine, on which the rest of the engine components are installed: cylinders, crankshaft, oil pan, cylinder head.

It is precisely the malfunctions and repairs of the cylinder head that are of interest to us.Is it possible to repair the cylinder head with your own hands in a garage-home? And craftsmen answer unequivocally - yes, repairing the cylinder head with your own hands is possible.

Let's start by clarifying that repairing a cylinder head is a complicated operation and will require from you: a little bit of understanding of the block device, the presence of a special locksmith tool and the ability to own it.

Basic tools required for cylinder head repair

• Mandrel for pressing in valve stem seals.
• Micrometer for measuring valves and guide sleeves.
• Reamer for unrolling new bushings.
• Mandrel for pressing out bushings.
• Mandrel for pressing in bushings.
• Devices for drying valve springs.
• Set of countersinks for the restoration of valve seats.
• Electric hotplate for heating the cylinder head during troubleshooting and before pressing the bushings.

Do not forget about the necessary spare parts and tags

As a rule, almost any repair of a cylinder head requires its dismantling. Exceptions are, for example, replacement of valve stem seals. Therefore, before starting to dismantle the cylinder head, think about purchasing the necessary set of spare parts.

Today's market provides Head Sets (or, in simple terms, upper sets), which include a cylinder head gasket and all the oil seals and gaskets located above the main gasket.

Well, the tool and the minimum kit are ready, we start troubleshooting the cylinder head.