4-8-7-4-klapany.html

4.8.7.4. Valves

To remove a deposit from valves. To check whether the core is deformed and whether there are no cracks on a plate; at damages to replace the valve.

To check whether it is not too worn-out and whether the working facet is damaged. When grinding a working facet of the valve on the grinder to sustain the facet corner equal 45 °30' ± 5'; and to track that thickness of a cylindrical part of a plate of the valve after grinding was not less than 0,5 mm.

The directing plugs of valves

To check a gap between the directing plugs and a core of the valve, having measured diameter of a core of the valve and an opening of the directing plug.

In case of wear of plugs more than on 0,08 mm they are pressed off in the direction of the combustion chamber outside by means of a special mandrel and the hammer or under a press.

After a press fitting the opening of the directing plug is developed to diameter 8,022... 8,040 mm for inlet valves and to diameter 8,029... 8,047 for final valves. At the same time ovality and conicity of an opening to 0,01 mm are allowed.

If the increased gap between the directing plug and the valve cannot be eliminated with replacement of the valve, replace plugs of valves, using a mandrel (fig. of Vypressovk of the directing plugs).

For replacement of two guides of plugs of inlet and final valves of the first and fourth cylinders to turn off two hairpins of fastening of the case of bearings of the camshaft as they prevent installation of a mandrel.

It is necessary to press the directing plugs with the put-on lock ring against the stop of a ring in the cylinder head plane.

After a press fitting to develop openings in the directing plugs development.

Then to proshlifovat a saddle of the valve and to bring width of a working facet to the necessary sizes as it is stated above.

Maslootrazhatelny caps

At maslootrazhatelny caps peelings of rubber from fittings, cracks and excessive wear of a working edge are not allowed.

At repair of the engine maslootrazhatelny caps are always recommended to be replaced new.

The damaged maslootrazhatelny caps can be replaced, without removing a head of the block of cylinders from the engine. For this purpose it is necessary to remove the case of bearings of the camshaft, to install the piston of the corresponding cylinder in VMT and to remove valve springs, as shown in rice. Removal of springs of valves. Then to remove the damaged cap from the directing plug and a mandrel to napressovat a new cap on the directing plug.

Levers of valves

To check a condition of the working surfaces of the lever which are interfaced to a valve core, to a cam of the camshaft and to the spherical end of an adjusting bolt. If on these surfaces there were teases or risks, to replace the lever new.

If deformation or other damages on the plug of an adjusting bolt of the lever or on the bolt is found, to replace details.

Springs

To be convinced whether is not present on springs of cracks and whether their elasticity decreased for what to check deformation of springs under loading (fig. A specification for check of an external spring of the valve of the engine of fashion. 2106, the Specification for check of an internal spring of the valve of the engine of fashion. 2106, Scheme of check of a spring of the lever).

For springs of levers (see rice. The scheme of check of a spring of the lever) the size A (a spring in a free state) has to be 35 mm, and the size B under loading (55 ± 6) N [(5,5 ± 0,6) kgf] – 43 mm.

Laying of a head of the block of cylinders

The surfaces of laying should not have damages. They have to be equal, without dents, cracks, swellings and breaks. Peeling of obkladochny material from fittings is not allowed.

On a fringing of openings there should not be cracks, progar and peelings.

However, even if the laying removed from the engine conforms to the above-stated requirements, at assembly of the engine it is recommended to replace it new.

Check of tightness of valves

To carefully clear saddles and valves and to establish a head of the block of cylinders on a support (fig. Check of tightness of valves).

To insert valves and the corresponding guides of the plug and to close openings of spark plugs traffic jams.

To install adaptation in the situation specified rice. Check of tightness of valves, and, strongly pressing the lever to create a rubber pear ^{pressure of 0,5 kgfs/sq.m}.

During 10 sec. pressure drop should not be observed.

If facets of valves and their saddles are not interfaced completely, leak of air will be noted by movement of an arrow towards zero. In this case to repeat grinding of a working facet of the valve and a saddle on a head of the block of cylinders, carefully carrying out the above-stated operations.

Tightness of valves can also be checked, having poured kerosene in inlet and final cavities of a head of the block of cylinders. At endurance within 3 min. it should not be observed kerosene leaks via valves.

Check of tightness of a head of the block of cylinders

For hydraulic test for tightness of a shirt of cooling of a head of the block of cylinders it is necessary to make the following:

 – to establish on a detail head, devices which are included in the package (fig. Check of tightness of a head of the block of cylinders on adaptation);
 – to force the pump water in a head under pressure of 5 ^kgfs/sq.m.

Within 2 min. leak of water from a head should not be observed. At detection of cracks to replace a head of the block of cylinders.