Dismantling, check of a technical condition, repair and assembly of a head of the block цилиндровa. Nissan Almera (from 1995 to 1999 of release)
Nissan Almera service from 1995 to 2000 in N15 body
1. General information
2. The general requirements to car repairs
3. Operation and car maintenance
4. Petrol engines
4.1. Removal and installation of the power unit
4.2. Dismantling and engine assembly
4.3. Block of cylinders
4.4. Shatunno-porshnevaya group
4.5. Cranked shaft and flywheel
4.6. Gazoraspredeleniye mechanism
4.7. Head of the block of cylinders of GA14DE and GA16DE engines
4.7.1. Removal of a head of the block of cylinders
4.7.2. Installation of a head of the block of cylinders
4.7.3. Dismantling, check of a technical condition, repair and assembly of a head of the block цилиндровa
4.7.4. Check and adjustment of gaps in the mechanism of a drive of valves
4.8. Head of the block of cylinders of the SR20DE engine
4.9. Cooling system
4.10. Greasing system
4.11. System of production of the fulfilled gases
4.12. Power supply system
4.13. Complex control system of the engine (KSUD)
5. Diesel engines
6. Transmission
7. Running gear
8. Steering
9. Brake system
10. Electric equipment
11. Body
12. Appendices
13. Electric equipment schemes
 







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4.7.3. Dismantling, check of a technical condition, repair and assembly of a head of the block цилиндровa

Establish a head of the block of cylinders on a support. Put labels on removed details that correctly them to establish at assembly. Remove the inlet pipeline together with the fuel highway. Disconnect from a head the pipeline of system of a retsirkulyatsiya of the fulfilled gases. Disconnect a final collector, previously having removed from it thermoisolating screen. Take out adjusting washers and pushers. Remove valves by means of the adaptation for compression of springs of the Facom U43LA type and lay for each valve separately crackers, a plate of a spring, a basic washer. Clear all details. Remove from directing plugs maslootrazhayushchy caps. To clean the laying remains from details from an aluminum alloy, it is possible to use a shaber or other sharp tool. However act carefully as it can lead to damage of surfaces of interface. It is preferable to use to this purpose chemical solvent of the Loctite — Decaploc 88 or Decapjoint type.
Repair of a head of the block of cylinders demands the special equipment therefore it is desirable to lead it in repair shops.
Examine the removed details, be convinced of lack of cracks, chips, considerable wear of a working surface and other defects. Are instructed on check of a technical condition of the main details of a head of the block of cylinders below.

Directing plugs of valves

Fig. 2.31. Installation of directing plugs of valves: and = 11,5 — 11,7 mm


Are pressed in a head of the block of cylinders (fig. 2.31). Repair plugs with increase external and reduced internal are provided in diameters. Vypressovka of worn-out plugs is carried out by means of a press and an opravka.
Previously warm up a head in an oil bath to temperature 110 — 120 ° S.Zatem chisel openings under the plug of the repair size. A press fitting of plugs to a head carry out also after its heating to the specified temperature then develop an internal opening of the pressed plug under diameter of a core of the valve.

Valves

Fig. 2.32. Geometrical sizes of the valve: Е — thickness of a cylindrical part of a plate of the valve; D — diameter of a plate of the valve; d — diameter of a core of the valve; L — total length of the valve;
a — a corner of a working facet of the valve


The gap between a core of the valve and the directing plug should not exceed admissible size. As valves of the repair sizes are not provided, it is necessary to replace the valve and the plug in pair. A head of the valve grind and grind in only within the sizes specified in tab. 2.6. After grinding of facets carefully clear a head of the block of cylinders and check tightness of valves. The geometrical sizes of the valve are specified fig. 2.32.

Saddles of valves

Fig. 2.33. Geometrical sizes of saddles of valves: And — inlet; B — final; D1 — external diameter of a working facet; D2 — internal diameter of a working facet; L — width of a working facet; a — a corner of a working facet; b1 — a corner of the top facet; b2 — a corner of the bottom facet


Are pressed in a head of the block of cylinders. Saddles can be ground within the sizes specified in tab. 2.5. Replacement of saddles carry out after heating of a head of the block of cylinders in an oil bath to temperature 110 — 120 ° With with press and opravka use. After grinding of facets carefully clear a head of the block of cylinders and check tightness of saddles. The geometrical sizes of saddles are specified on fig. 2.33.

Table 2.5 Dimensional characteristics of saddles of valves of GA14DE and GA16DE engines
Characteristic
Inlet valves
Final valves
Width of a working facet, mm
1,06-1,34
1,20-1,68
External diameter of a working facet, mm
29,5-29,7
23,5-23,7
Internal diameter of a working facet, mm
27,8-28,0
-
Corner of a working facet
45 °
-
Corner of the top facet
30 °
15 °
Corner of the bottom facet
60 °
-

Maslootrazhatelnye caps
Always are subject to replacement at head repair. Replace them after removal of basic washers of valves by means of an opravka.

Springs of valves
Check a corner of a deviation of rounds of a spring from an axis. At a skalyvaniye of a protective varnish it is recommended to replace springs because of possibility of a rupture of a spring at operation. Do not clear a spring with application of gasoline or трихлорэтилена as these substances can dissolve a protective varnish.

Pushers
Check a condition of a surface and a gap between pushers and walls of their nests. Examine a surface of nests of pushers. In case of the wear exceeding admissible, replace pushers or a head of the block of cylinders.

Surface of interface of a head with the block of cylinders
If the deviation from planeness of a surface of interface of a head of the block of cylinders with the block exceeds 0,1 mm and the camshaft freely rotates, carry out grinding of a head of the block of cylinders. The thickness of a removed layer of metal should not exceed 0,2 mm. Otherwise replace a head of the block of cylinders.

Camshafts and asterisks
Examine a surface of camshafts and their support, paying special attention to wear of cams and necks. Check their geometrical sizes. At a considerable deviation of measured sizes from admissible replace a shaft or a head of the block of cylinders. Check radial and axial palpation of shaft and asterisks. Replace details at considerable wear.

Fig. 2.34. Details of a head of the block of cylinders:
1 — a stopper of a maslozapravochny mouth;
2 — a cover of a head of the block of cylinders; 3 — laying of a cover of a head of the block of cylinders;
4 — a cover of the bearing of a camshaft of inlet valves; 5 — a cover of the bearing of a camshaft of final valves;
6 — a bolt of fastening of a head of the block of cylinders;
7 — a head of the block of cylinders; 8 — the directing plug of the valve; 9 — a forward cover of a head of the block of cylinders; 10 — laying of a head of the block of cylinders; 11 — a valve saddle


At assembly of a head of the block of cylinders it is necessary to grease with engine oil of recommended quality all adjoining details. At work be guided fig. 2.34.
Clear a head of the block of cylinders and all removed details. Blow channels of a head of the block of cylinders, having paid special attention to channels of greasing of camshafts. When using earlier removed valves establish them on the places.
Assembly of the klapanny mechanism carry out in such sequence. Insert the valve into directing plug, put on directing plug a basic washer, напрессуйте a new maslosjemny cap, put a spring and a plate of a spring. Compress the adaptation a spring and establish crackers. Put on an edge a head of the block of cylinders and, slightly tapping with a copper or bronze hammer along the edges of cores of valves, achieve the correct landing of crackers. Establish on the places pushers with adjusting washers. Establish a final collector with new laying, then the thermoisolating screen. Establish the inlet pipeline with new laying. Establish the HORN pipeline between the inlet pipeline and a final collector.

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