5.13.4. Dismantling, repair and assembly of a head of the block of cylinders

Fig. 5.9. Details of a head of the block of cylinders: 1 – block head; 2 – inlet camshaft; 3 – epiploon; 4 – final camshaft; 5 – case of bearings of camshafts; 6 – block head cover; 7 – arm of fastening of a plait of wires; 8 – caps; And – a distinctive corbel of the inlet camshaft

The head of 1 (fig. 5.9) of the block of cylinders the general for four cylinders, is cast from aluminum alloy, with combustion chambers of a tent form. Inlet and final channels are brought to the different parties of a head of the block. Valves are located by V-shapedly in two ranks: on the one hand inlet, with another — final.
In a head ceramic-metal saddles of valves and brass guides of the plug of valves are pressed. Internal diameter of the directing plugs (7±0,015) mm, external (for the plugs delivered in spare parts) – 12,079–12,090 mm and 12,279–12,290 mm (the plug increased by 0,2 mm).
Diameter of a plate of the inlet valve of 29 mm, final – 25,5 mm. Diameter of a core of the inlet valve (6,975±0,007) mm, final – (6,965±0,007) mm.
About one spring is installed on each valve. Spring length in a free condition of 38,19 mm, under load (240±9,6) N [(24,5±0,98) kgfs] has to be 32 mm, and under load (550±27,5) N [(56,1±2,8) kgfs] – 24 mm.
Valves are put in action by cams of camshafts through the cylindrical hydropushers located in the directing openings of a head of the block of cylinders on an axis of openings under valves. Hydropushers automatically eliminate a gap in the valvate mechanism therefore at maintenance of the car it is not required to check and regulate a gap in the valvate mechanism.
Oil for work of hydropushers is brought from the lubrication system on the vertical channel in the block of cylinders to the channel in a head of the block of cylinders about the 5th bolt of fastening, and then on the top channels executed on the lower plane of the case of bearings. On the same channels oil and for lubricant of necks of camshafts is brought. In the vertical channel of a head of the block of cylinders the backpressure ball valve which is not allowing discharge of oil from the top channels after an engine stop is located.
For the drive of valves two camshafts serve: inlet and final. Shaft are cast from cast iron and supplied with five basic necks which rotate in the nests executed in a head of the block of cylinders and in one general case of bearings of the camshaft. For increase in wear resistance working surfaces of cams and a neck under an epiploon are bleached. To distinguish the inlet camshaft from final, on inlet to a shaft about the first support the distinctive corbel is executed And.
Shaft refrain from axial movements by the persistent fillets located on both sides from a forward support. The forward ends of camshafts are condensed with samopodzhimny rubber epiploons. The back openings located on an axis of shaft in a head of the block of cylinders and the case of bearings are closed by the rubberized cap-type caps.
It will be required to you: the device for compression of valvate springs, the device for a vypressovka and a mandrel for a press fitting of oil scraper caps, face keys "on 8", "on 10", "on 13", keys "on 19", "on 21", a hexagon "on 10", the screw-driver, tweezers.
1. Remove a head of the block of cylinders from the engine (see. "Replacement of laying of a head of the block of cylinders").
2. Establish a block head by camshafts up, having enclosed under it wooden laying not to damage valves.
3. Turn off a face head "on 13" three nuts of fastening of the left support of the power unit …
4. … also remove a support.
5. Turn out a key "on 10" two bolts of fastening of an arm of a fuel tube …
6. … also remove an arm.
7. Turn out a key "on 10" two bolts of fastening of the sensor of phases …
8. … also remove the sensor.
9. Turn out a key "on 21" the sensor of an alarm lamp of emergency pressure drop of oil from the case of bearings of camshafts.
10. Turn out a key "on 19" from the thermostat the sensor of temperature of cooling liquid.
11. Turn out a key "on 21" the sensor of the index of temperature of cooling liquid from a back end face of a head of the block.
12. Turn off a key "on 13" two nuts of fastening of the thermostat.
13. Remove the thermostat …
14. … and the sealing laying established under it.
15. Turn out a candle key of a spark plug incidentally not to damage them.
16. Turn out a face head "on 8" twenty bolts of fastening of the case of bearings of camshafts...
17. … also remove the case.
18. Take out camshafts from support of a head of the block of cylinders and remove epiploons from their forward ends.
19. Take out caps from a back end face of a head of the block.
20. Take hydropushers of valves from openings of a head of the block of cylinders.
21. Clear combustion chambers of a deposit. Examine a block head. If on it there are cracks or traces of a progar in combustion chambers, replace a head. Remove agnails and zaboina on the block head plane.
22. Check planeness of a surface adjacent to the block of cylinders. For this purpose put a ruler an edge on a head surface at first in the middle lengthways, and then on diagonals and measure by the probe a gap between a surface of a head and a ruler. If the gap is more than 0,1 mm, it is possible to proshlifovat a privalochny surface. For this purpose address in a specialized workshop.
23. Similarly check planeness of privalochny surfaces of a head of the block under an inlet collector …
24. … and katkollektor. Not planeness of these surfaces should not exceed 0,1 mm.
25. For check of tightness of a head of the block muffle an opening in a head under a thermostat nest. It can be made, for example, having established deaf laying from a dense cardboard under a nest and having wrapped nuts of its fastening. Screw into place the sensor of the index of temperature of cooling liquid if it was turned out.
26. Fill in kerosene to canals of a water shirt. If kerosene level at endurance of 15-20 min. goes down, so in a head there are cracks and it should be replaced. After check do not forget to remove cardboard laying and to take traffic jams.
27. Check a condition of basic surfaces under necks of camshafts on a block head …
28. … and case of bearings. If at least on one of them there are wear tracks, teases or deep risks, replace a head and the case of bearings.
29. Wash out oil channels. For this purpose muffle the vertical oil channel from the combustion chamber (the channel is between the 3rd and 4th cylinders)...
30.... fill in gasoline to the oil canal of a head of the block …
31. … and also sustain cases of bearings of camshafts 15–20 min. Pour out gasoline, take out a cap and finally wash out channels gasoline by means of a pear.
32. For check of tightness of valves screw candles and fill in kerosene in combustion chambers. If within 3 min. kerosene does not filter from combustion chambers into canals, valves are tight. Otherwise grind in (see. "Grinding in of valves") or replace valves.


Note
For replacement or grinding in of valves remove the following details from a head of the block of cylinders: 1 – valve; 2 – spring; 3 – plate; 4 – crackers.

33. Establish a suitable emphasis under the removed valve.
34. Install the device for compression of springs of valves, having screwed a bolt of fastening of a cover of the bearing of the camshaft in one of block head openings and having hooked on adaptation for this bolt. Squeeze adaptation a valve spring.
35. Take out two crackers from the top plate of a spring by means of tweezers or the magnetized screw-driver. Then remove adaptation.

Good advice
If the effort of movement of the lever of adaptation considerably increases, and crackers do not leave a valve pro-point, strike easy blow with the hammer to a plate of springs that crackers were released.

36. Remove a plate of a spring.
37. Remove a spring.
38. Push and take out the valve from a block head.
39. Press an oil scraper cap from the directing valve plug adaptation or passatizha (see. "Replacement of oil scraper caps").

40. Clear a deposit from the valve the suitable tool (for example, a metal brush). Then attentively examine the valve.
41. Replace valves with the following defects: deep risks and scratches on a working facet 1, cracks, deformation of a core 3, a buckling of a plate 2, traces of a progar. Superficial risks and scratches on a working facet can be removed grinding in of valves (see. "Grinding in of valves").
42. If damages of a working facet of valves cannot be removed grinding in, it is possible to proshlifovat a facet on the special machine in a specialized workshop.
43. Check a condition of saddles of valves. On working facets of saddles there should not be wear tracks, sinks, corrosion, etc. Saddles of valves can be replaced in a specialized workshop. Insignificant damages (small risks, scratches and so forth) can be removed grinding in of valves (see. "Grinding in of valves").
44. More major defects of saddles of valves eliminate with grinding. Saddles are recommended to be ground in a specialized workshop.

Fig. 5.10. Places of processing of facets of saddles of valves

45. Having metalwork skill, this work can be performed manually by means of a set of special mills. In the beginning process a facet and (fig. 5.10) at an angle 15 °, then a facet at an angle 20 ° and a facet in at an angle 45 °. After grinding it is necessary to grind in valves (see. "Grinding in of valves").
46. Check a condition of springs of valves. Replace the bent, broken or having cracks of a spring.

Fig. 5.11. Parameters of check of a spring of the valve

47. For check of elasticity of an external spring measure its height in a free state, and then under two various loadings (fig. 5.11). If the spring does not correspond to the required parameters, replace it.
48. Examine hydropushers of valves. If on a working surface 1 there are teases, scratches and other defects, replace hydropushers. Measure outer diameters of pushers, replace worn-out pushers. On working surfaces 2 should not be zadir, забоин, scratches, traces of step or uneven wear, a natir of metal. Hydropushers with such defects should be replaced. On surfaces 2 concentric traces extra earnings with camshaft cams are allowed.

Fig. 5.12. Sizes of valves and their guides of plugs

49. Check gaps between the directing plugs and valves. The gap is calculated as a difference between diameter of an opening in the plug and diameter of a core of the valve (fig. 5.12). Check of a gap is recommended to be carried out in a specialized workshop as for measurement of diameter of plugs the special tool (nutromer) is necessary.

Gaps between the valve and the directing plug, mm:
nominal for inlet and final valves..... 0,018–0,047
maximum permissible for inlet and final valves..... 0,300

50. If the gap did not reach maximum permissible, it is possible to try to eliminate it with replacement of the valve. If it does not manage to be made or the gap exceeds maximum permissible, replace the directing plug. For this purpose to a vypressuyta from the combustion chamber the defective plug a special mandrel, previously having measured height of a vystupaniye of the top part of the plug over a block head surface.
51. Cool the new plug (for example, by means of the carbon dioxide fire extinguisher), oil it engine, insert into a special mandrel and press from the camshaft so that height of a vystupaniye of the top part of the plug corresponded to the measured value. Develop an opening in the plug by means of development to 7,000–7,015 mm for inlet and final valves.
52. If the old valve is installed, remove agnails about the protocheck under crackers. After that it is necessary to grind in the valve to a saddle (see. "Grinding in of valves").
53. Install valves in a block head according to earlier made marking, previously having oiled cores engine.
54. Establish oil scraper caps (see. "Replacement of oil scraper caps").
55. Install camshafts and the case of bearings of camshafts (see. "Replacement of oil scraper caps").
56. Establish all details and knots removed at its dismantling on a block head.