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Disassembly, repair and assembly of cylinder head
If you need a repair cylinder head of the engine mounted on the car, remove it (see. "Replacing cylinder head gasket"). In most cases, repair of the cylinder head is lapped or replace valves, valve seats grinding. In these faults, as a violation of tightness channels shirt cooling and warpage mating surface of the cylinder block, cylinder head replaced. You will need: the keys "10", "12", "13" candle key, a magnetic screwdriver (or forceps), a device to compress the valve springs.
| Fig. 5.5. Sequence of loosening the nuts and bolts of an inlet pipe |
2. Remove the pressure levers of valves and guides crackers leverage (see. "Replacement of hydraulic valve clearance"). | | 3. Remove the ten bolts and nuts intake pipe in the sequence shown in Fig. 5.5, remove the pins from the inlet tube assembly from the rail, the throttle assembly and the coolant hose ... | 4. ... and its lining. |
| Fig. 5.6. Sequence of loosening the nuts securing the exhaust manifold |
6. Remove the eight nuts the exhaust manifold in the sequence shown in Fig. 5.6. | | 7. Remove the pins from the exhaust manifold and mounted underneath the pad. | |
11. Install the spring compressor valve, compress the spring ...
| Fig. 5.7. Installing the spring compressor valves: 1 - cylinder head; 2 - spring compressor |
HELPFUL ADVICE To compress the spring valve cylinder head, removed from the engine, it is more convenient to use the device as shown in Fig. 5.7. In this case, no need to install a support under "rassuharivaemy" valve and, moreover, the device records the spring in a compressed state, which greatly facilitates removal of the biscuit. |
| | 12. ... remove crackers ... | 13 ... upper spring seat and the spring ... |
| | 14. ... the lower plate springs ... | 15. ... and rotating mechanism outlet valves, and remove the valve from the guides. |
A WARNING After a long operation at the upper end of the valve can be formed mushroom-shaped burr. Before removing the valve from the directing plug remove the burr of needle files. It is strictly forbidden to beat the valve guide sleeve of a hammer through the mandrel without deburring, as this will inevitably be damaged by the inner surface of the sleeve. |
16. Remove the resinous sediments on the upper surface of the head and of the inlet channel. These deposits can be softened and rinse with kerosene or diesel fuel. 17. Clean the carbon deposits from the combustion chamber and the exhaust ports. Nagar remove the round metal brush installed in the chuck of an electric.
HELPFUL HINTS Pre-soak soot kerosene. Be careful: Avoid breathing dust generated during cleaning of combustion chambers. To prevent dust periodically moisten with kerosene soot. |
18. Clean the inside surface of the valve guides a thin cylindrical copper wire brush clamped in the chuck of an electric. 19. Remove the contact surface of the head to the cylinder block burnt remains of the gasket.
A WARNING Do not clean the gasket surface of the head with metal brushes or emery cloth. Use a shovel from solid wood or plastic, pre-softened solvent residues lining. |
20. After cleaning, inspect the cylinder head to prevent its operation damaged threaded holes, cracks (especially between the valve seats and exhaust ducts), corrosion, inclusions of foreign materials, shells and fistulas.
A WARNING It is forbidden to brew cracks shells and fistulas. Replace defective head. |
21. Test with a metal ruler, fixed to the edge, and the flatness of the probe head contact surface to the block in the longitudinal and transverse directions as well as diagonals. If the gap between the edge line and the head surface exceeds 0.1 mm, replace head. 22. Clean the gasket from the remnants of soot and flange surfaces of the head to set the intake pipe and the exhaust manifold. 23. Check for deformation of the flanges to the inlet pipe and the exhaust manifold, replace the deformed head. 24. Damaged screw holes sweep thread taps repair or installation repair sleeve (vvertysha). 25. Check the tightness of the plugs the cooling jacket. With the weakening of their landing restore its coinage. 26. Determine the valve guide wear by measuring the internal diameter of the sleeve hole, the diameter of the valve stem and the difference between these dimensions defining the gap. The clearance for the intake valves to be 0,030-0,065 mm for the exhaust - 0,050-0,085 mm. 27. If the limit is exceeded, repair sleeve deployment to the nearest of the three repair sizes with an increase in the diameter of the holes on the 0.075 mm, 0.150 and 0.250 mm relative to the nominal diameter. In this case, they must be installed valves respective oversize ensuring a nominal clearance in conjunction. Deploy hole plugs, using a set of sweeps with guide shaft. To avoid chipping the surface layer removes the metal sleeve on each pass and submission tools should be minimal.
A WARNING Guide bushings made of steel powder metallurgy, pressed into the cylinder head and can not be replaced. |
NOTES The guide sleeve and valve repair sizes can be installed due to technological reasons the factory during assembly of the new motor. To facilitate the selection of repair kits and parts in the sleeve valves are factory-applied labeling (Table 5.2.) Used in the production process of the manufacturer and the service used at service stations. |
Table 5.2 The repair sizes of valves and guides * Marked with "-" (dash)
| Fig. 5.8. Profile valve seats: and - an inlet valve; b - exhaust valve |
| | 28. Check the condition of the valve seats. On working facets of saddles should not be signs of wear, pitting, corrosion, etc. Saddle valves can be replaced in a specialized workshop. Minor damage (small risks, scratches, etc.) Can be derived lapping valve (see. "Lapping valves"). | 29. More significant valve seats eliminate defects by grinding, soaking the dimensions shown in Fig. 5.8. Saddles recommended to grind in a specialized workshop, as it requires special tools and equipment. |
 30. Remove carbon from valves and inspect them. Deformation of the valve stem, and a crack on his plate is not allowed. If damaged, replace the valve. Make sure there are not too worn out and not damaged working facet. Allowed grinding working facet of valves (in the repair shops have the appropriate equipment). After grinding chamfer angle relative to the plane of the plates should be 45 ?� 30 '?� 5', and the thickness of the cylindrical portion dish should be not less than 0.5 mm. Minor scratches on the risks and chamfer can be displayed to the lapping of the valve seat (see. "Lapping valves").
A WARNING In order for valve stems are not formed risks do not clean their wire brush and metal scraper. |
31. Check the concentricity of the location of the valve disc and seat: put on a facet of the valve head a thin layer of paint (for example, Prussian Blue), insert it into the guide sleeve and lightly pressed against the seat, turn. On the trail of paint on the facet of a saddle can judge the concentric valve and seat.
| Fig. 5.9. Valve wear zone 1 - zone of least wear rod; 2 - end of the rod; 3 - groove for crackers; 4 - the most exposed area of the rod; 5 - working facet; 6 - edge plates |
32. Check the wear of the valve stem in the areas shown in Fig. 5.9. Nominal diameter rod all valves 7,935-7,950 mm. 33. Check the condition of grooves 3 (see. Fig. 5.9) of the valve stem by crackers. If you find traces of chipping the edges of grooves of the cylindrical part and wear, replace the valve. 34. Replace the valve seals, regardless of their status. 35. Inspect the valve springs. Cracks and reduced elasticity of the springs are not allowed. If possible, determine the elasticity of the spring force that. According to the specifications, it should be 625-650 H when the length of the spring 21.5 mm and with a length of 275-290 H 31.5 mm. Curved spring (deflection in the free state of more than 1.6 mm) and a spring cracked replace. 36. Check the condition of the support plates of springs. Replace the dish with a considerable wear grooves for supporting the spring. 37. Gaskets intake pipe, exhaust manifold and cylinder head, always replace with new, as the shot, do not even look damaged pads can be highly compacted, and will not provide a tight seal.
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