2.2.10. Service of valves


  1. Check a condition of valves as it is described in the Section Cleaning and check of a condition of a head of cylinders and components (items 2 and 1). Replace all valves having wear tracks or damages.
  2. If valves at this stage of check seem satisfactory, measure by a micrometer in several points diameter of a core of the valve. Any noticeable difference in indications of the measuring instrument testifies to wear of a core of the valve. If any of these conditions takes place, the valve (valves) should be replaced.
  3. If a condition of valves satisfactory, then them it is necessary to grind in in the corresponding saddles to provide tightness. If the saddle has insignificant dents or it was already exposed to boring, then they should be ground in thin polishing paste. Usually large polishing paste is not used if only the saddle has no strong progar or deep dents. In that case the head of cylinders and valves have to be checked by the expert to make the decision on boring of a saddle or even on replacement of the valve or a saddle.
  4. Grinding in of valves is made as follows. Turn a head and establish on a workbench, having enclosed on both sides tree whetstones to provide a gap with cores of valves.
  1. Apply a small amount of polishing paste of the corresponding granularity on a valve saddle facet and attach a sucker of the polishing tool to a valve head. Grind in a valve head to a saddle returnable rotary motions, periodically for redistribution of polishing paste raising the valve. Be not overzealous.

If under a head of the valve to establish not a hard spring, then operation on grinding in will be considerably facilitated.

  1. If large polishing paste is used, then it is necessary to make grinding in until on a saddle and the valve not plain opaque surfaces are reached, then it is necessary to remove paste and to repeat process with thin polishing paste. Operation on grinding in will be complete when on the valve and a saddle smooth light gray opaque surfaces without gaps are received. Do not grind in valves more, than it is necessary.
  2. After grinding in of all valves before assembly of a head of cylinders carefully wash away all traces of pritirochny paste, using for this purpose kerosene or suitable solvent.