Springs of valves and directing plugs of valves

For high-grade control of springs of valves it is necessary to use the special tool for check of springs. If it is not present, then establish springs in a row on a smooth surface so that the closed nakatka was in the lower part. Put near a spring a steel corner and measure a gap between the top part of a spring and a corner. The gap should not make more than 2,0 mm. Otherwise the spring is warped.

Directing plugs of valves

Fig. 38. Control of palpation of a core of the valve in the directing plug by means of the measuring VW387 device

Control of palpation of a core of the valve in the directing plug is carried out by means of the measuring VW387 device, the strelochny indicator (fig. 38) .

Fig. 37. Details of the mechanism of a drive of valves: 1 — a hydraulic pusher; 2 — half of a core of the valve (crackers); 3 — the top plate of a spring of the valve; 4 — valve springs; 5 — a maslootrazhatelny cap; 6 — the directing plug of the valve; 7 — a head of the block of cylinders; 8 — valves; a — height of a head of the block of cylinders

Shake a plate of the valve in the top part forward-back and check indications of the strelochny indicator. If it shows size more than 1,0 mm on inlet valves and more than — on final, the directing plug of the valve it is necessary to replace 1,3 mm. It is necessary to check also the general condition of a head of the block of cylinders before replacing directing plugs of valves. A head of the block of cylinders with small scratches between saddles of valves or between a saddle of the valve and a carving of an opening of a candle can be переточены and are used repeatedly provided that the width of scratches does not exceed 0,5 mm. After a repoint of a head of the block of cylinders the size a (see fig. 37 ) should be not less than 139,50 mm. It is the minimum size. The nominal size of height of a head of the block of cylinders makes (140 ± 0,1) mm. Measurements should be carried out either a calliper, or a measuring ruler, having put a head of the block of cylinders on an equal surface;

- put a head of the block of cylinders on a pressing table for removal of the directing plug of the valve;

Fig. 39. Vypressovyvaniye of the directing plug of the valve. New plugs are pressed from the same party

- removal of the directing plug of the valve is made by their vypressovyvaniye from camshafts of a head of the block of cylinders (fig. 39) by means of a punch.

The head of the block of cylinders can be heated up to facilitate this work. On a punch it is necessary to fasten a pin which approaches on the size to inside of the directing plug of the valve:

- at replacement of the directing plug of the valve change also the valve. Then it is necessary переточить saddles of valves;

- new directing plugs of valves before installation grease with engine oil and впрессуйте them from camshafts in a cold head of the block of cylinders so that the fillet of the directing plug of the valve entered into a head of the block of cylinders. Pressure of a press fitting thus should not be more than 1 t, otherwise a fillet can be cut off. The head of the block of cylinders should lie on absolutely flat surface;

- after a press fitting develop openings in the directing plug of inlet and final valves development on 7,0 mm;

- after replacement of directing plugs of valves of a saddle of valves it is necessary to grind in;

- after grinding in carefully wash out saddles and channels of a head of cylinders and blow the compressed air.

Saddles of valves

Check and repair of saddles of valves is carried out as follows:

Fig. 40. Saddles of inlet valves: a — diameter of a saddle of the valve (look the table of adjustments and control); b — the maximum size after repair; c — width of a saddle of the valve, 1,7 mm; z — bottom edge of a head of the block of cylinders; 30 ° — the top adjustment corner; 45 ° — a corner of a facet of a saddle of the valve; 75 ° — the bottom adjustment corner

- check all saddles of valves on wear and existence of scratches. On working facets of saddles (a zone of contact to valves) there should not be dot sinks, corrosion and damages. It is possible to eliminate small damages with grinding of saddles — 45 ° a mill. Thus remove as little as possible metal. It is possible to grind as manually, and by means of the grinding machine. If saddles are worn-out strongly, them follows отфрезеровать anew. The form of facets of saddles of valves is shown on

Fig. 41. Saddles of final valves: a — diameter of a saddle of the valve (look the table of adjustments and control); b — the maximum size after repair; c–valve saddles, 2,4 mm; z — bottom edge of a head of the block of cylinders; 30 ° — the top adjustment corner; 45 ° — a corner of a facet of a saddle of the valve

fig. 40 and 41 ;

- carry out the following measurements to observe the sizes b, for this purpose:

- insert the valve into its directing plug and press a valve saddle;

Fig. 42. Measurement of height of a ledge of the end of a core of the valve over the upper edge of a head of the block of cylinders

- measure height of a ledge of the end of a core of the valve over the upper edge of a head of the block of cylinders (fig. 42) . For this purpose put on the plane of a head of the block of cylinders a measuring ruler. On inlet valves it should make 33,9 mm, and on final valves — 34,1 mm;

- calculate size b for what it is necessary to subtract the minimum distance from the measured size.

It is necessary not to chisel a saddle of valves in a head of the block of cylinders too strongly. Saddles of valves follows отфрезеровать and in case new directing plugs were established. For this purpose it is necessary:

- slightly to process a mill at an angle 45 ° and after that mill at an angle 30 ° upper edge of a saddle of the valve, to reduce width of a saddle from the valve and to finish it to value of 1,7 mm — for inlet and 2,0 mm — for final valves. Processing should be stopped, as soon as the sizes of a saddle of the valve will reach the specified sizes. Saddles of final valves have limiters of diameter. At carrying out processing watch to damaging these limiters;

Fig. 43. Valve grinding by means of a sucker

- grind the processed saddles of valves. For this purpose put on a valve saddle a small amount of pritirochny diamond paste and establish the valve in the corresponding saddle. Attach on the valve a sucker and rotate the valve with its help forward-back (fig. 43) ;

- check a valve saddle in a place of a plate of the valve and a sealing ring. The continuous, opaque ring on both details should be visible;

- put with a pencil some hyphens on a ring in a plate of the valve. Hyphens should be drawn round a ring with an interval about 1 mm. After that carefully insert the valve into directing plug, lower it on a saddle and turn on a circle on 90 °, making the valve small effort;

- take out the valve and check, whether the lines put with a pencil from a sealing ring disappeared;

- after grinding in carefully clear all parts of dirt and pritirochny paste. If the width of a saddle of the valve corresponds to the specified sizes, it is possible to establish a head of the block of cylinders. Otherwise saddles of valves are necessary for processing repeatedly or as a last resort to establish a new head of the block of cylinders.

Valves

Remove a deposit from valves. Check, whether the core is deformed and whether there are no cracks on a plate, for what:

Fig. 44. Control sizes of valves: a — diameter of a plate of the valve; b — diameter of a core of the valve; c — length of the valve

- carry out measurements according to fig. 44 and replace all valves inappropriate to these sizes. Sizes a, b and c can be taken from the table of admissions and control;

- if the end of a core of the valve is worn-out, it can be ground on the grinder provided that when polishing no more than 0,50 mm of metal will be removed;

Fig. 45. The sizes when grinding facets of valves: a= 45 °; a= at most 3,5 mm; b= at least 0,5 mm

- plates of inlet valves can be ground on the machine for grinding of valves provided that size b (fig. 45) will be not less than 0,5 mm.

Prevention Grinding on the machine is inadmissible for final valves as they are made of a special material. Only grinding in by means of paste it is possible to try to bring final valves into norm again. Otherwise it is necessary to replace them.

Head of the block of cylinders

Carefully wash up a head of the block of cylinders and clear oil channels. Remove a deposit from chambers of combustion and from a surface of final channels with a metal brush. Carefully clean the contact planes of a head of the block of cylinders and the block of cylinders. Examine a head of the block of cylinders. On support under necks of a camshaft and in openings under pushers of valves should not be задиров and damages. Cracks in any places of a head of the block of cylinders are not allowed.

Fig. 46. Check of a head of the block of cylinders on deformation by means of a measuring ruler and щупа

Check a surface of a head of the block of cylinders on deformation (fig. 46) .

For this purpose put on a head a measuring ruler and by means of measuring щупа check a gap lengthways, across and on a diagonal. If it does not exceed 0,10 mm, the head of the block of cylinders can be ground. In case the gap in any place is more, it is necessary to replace a head of the block of cylinders, as removal of a bigger layer of metal can negatively affect an engine compression.

Camshafts

Camshafts are not interchangeable first of all because of existence on one of them the Hall sensor. Shaft differ according to number for the order of spare parts.

At survey of camshafts pay attention to surfaces of basic necks (the location of bearings), cams which should be well polished and not have damages. If traces of jamming or deep risks are found, it is necessary to replace a camshaft.

Before installation of camshafts it is necessary to perform the following works:

Fig. 47. Measurement of radial palpation of a camshaft

- establish a camshaft extreme necks on two prisms or between clips of the lathe and establish the measuring device in a place of the average bearing (neck) of a camshaft (fig. 47) ;

- slowly rotate a camshaft and watch indications of the measuring device. If on instrument readings radial palpation exceeds 0,01 mm, the camshaft should be replaced, as it is deformed. In the similar way check the second shaft;

Fig. 48. Measurement of an axial gap of a camshaft

- for measurement of an axial gap of camshafts, insert them both in a head of the block of cylinders (without pushers), fix extreme bearings and place a head of the block of cylinders on a flat surface. Establish the measuring device from an end face of a head of the block of cylinders and shake a shaft forward-back in the axial direction ( fig. 48 , it is shown by shooters). The axial gap should not exceed 0,15 mm. Otherwise the working surface of a cover of the bearing is worn-out.