Lapping valves with their own hands. How to rub valves with your own hands without tools?

When repairing the engine, lapping of the valves is often required . This is a responsible job, for which it is necessary to have an appropriate tool at hand. Of course, you can do without it. So, how is the lapping of the valves handled?

When lapping is required

Many use a special tool, paste and suction cup for grinding the valves. However, not everyone knows how correctly this procedure is carried out. Saddles and valves have only a few types of defects:

• The chamfers are covered with shells or carbon deposits, but their shape is not changed;
• Chamfers are covered with carbon and shells, while their shape is changed.

In the latter case, something like steps can form on the surface of the part. In addition, the conical shape of the chamfer can change and become rounded.

Features lapping in both cases

If the shape of the chamfer is not broken, the usual lapping is carried out. If there are defects, the part is first treated with a lathe, and the valve seats are cleaned with cone-shaped cones. Of special importance are the dimensions of the devices.

To start, the valve seat is machined with a cutter with an angle of 45 °, then the upper band is cut with a cutter with an angle of 15 °, and a chamfer with an angle of 75 ° is removed in the lower part of the saddle. It is also possible to handle parts with abrasive wheels and a hand drill. The tools must have angles of 45 °, 15 ° and 75 °.

It should be noted that grinding the valves with a hand drill or screwdriver takes a lot of time. To accelerate the process, you can use an electric tool that can be tested in both directions, and also gradually rotate around the circumference.

Lapping paste

First of all, a paste is needed to lap the valves. This is the first thing you should buy in a specialized store. During the treatment, the paste is applied to the edge of the valve. Such a composition serves as a kind of small pelts. Thanks to the paste, it is easy to grip the valve to the socket. There are several main types of such tools. All of them have certain differences that affect the cost of production.

Classification of pastes

The paste for grinding the valves is classified according to the degree of surface treatment: for the initial treatment - large, for the final - fine-grained. The latter option is very popular, since such products are recommended by masters engaged in engine repair. Fine-grained paste allows you to quickly and correctly wipe the valves. In this case, much depends not on the composition of the means, but on the condition of facets and the details themselves. In addition, the lapping of the valves with their own hands is not always obtained from everyone. When self-processing is recommended to use a regular composition, the cost of which is 100 rubles per tube.

Do not buy the most expensive pasta. If there is a need in it, you can purchase it in the process.

"Grandfather's" cutter

Lapping the valves with your own hands is a simple process, if you know how and what to do. Previously, there were cutters for the repair of cylinder head. Such a device for grinding the valves was mainly used to restore the saddles of the parts. Some masters have been using such a tool to this day. Outwardly the device is a nozzle for the socket, made in the form of a valve seat. The cutter is fixed in a drill. The device is small and resembles a kind of drill.

Do we always need cutters?

Is such an instrument necessary? To answer the question posed, it is necessary to look at the saddles pressed into the heads. If their integrity is not violated, you can proceed to grinding. If they are damaged, for example by burnout, then it is recommended to treat them with special cutters. The technology in this case is quite simple. Initially, it is recommended that you change the guides and then grind them. In each case, an individual approach is required. You can buy a special device for grinding valves in almost any specialized store.

Or maybe put new valves?

New valves are not always required. Of course, if the details are slightly curved, then do not try to align them. The process will not work, and you will only waste your time and energy. In this case, it is better to visit the store with spare parts for vehicles and purchase a new kit.

When replacing parts, special attention should be given to their quality. The height of the valves should in any case be the same. The presence of roughness and roughness on the ends, rods and sealing working bevels is not allowed. It is recommended to polish the parts before shining to install the new kit. This process should be carried out not only on the valve rods, but also on the black neck of the valve, and on a flat plate. Due to this processing, the parts will become less carbon and heat. When working, seal chamfers are not recommended. They should only be rubbed against the saddles.

The machine for grinding the valves

Many for lapping valves make special devices. This may require a rubber hose and a conventional drill. Lapping of valves with their own hands in this case is carried out according to the following scheme:

1. Rubber hose is put on the drill. This may require a drill and several clamps.
2. At the end of the hose, a lapping paste is applied.
3. One of the engine valves is inserted into this hose. For reliable fixing, you can use clamps.
4. The valve is inserted into the socket, and its lapping begins.

With this method it is very important not to include the maximum speed on the drill. The process must proceed slowly and accurately. As for the revolutions, they should be from 400 to 500 per minute. When the speed increases, the saddles and valve belts become very hot. In the process of grinding it is not recommended to make circular motions. It is necessary to simulate the operation of the engine valve, while moving forward, and then back.

It should be noted that grinding the valves with a drill and a hose is a painstaking process that takes a long time.