65637bd9



3.1.2.7. Head of cylinders and valves


Careful cleaning of a head of the block of cylinders and details of the valvate mechanism with the subsequent check will allow to estimate amount of works on repair of the valvate mechanism.
Prevention

If the engine often overheated, then most likely the head of cylinders could warp, carefully check existence of signs of deformation of a head.

Cleaning

PERFORMANCE ORDER
1. Clear the demountable planes of a head of cylinders.
2. Clear combustion chambers, all openings and channels of a deposit, then wash out a head of cylinders solvent.
3. Remove massive deposits of a deposit from valves.

Check

Prevention

Before drawing a conclusion on need to regrinding of details surely perform all checks described below than the procedure.

HEAD OF CYLINDERS

PERFORMANCE ORDER
1. Attentively examine a head, check existence of cracks, traces of penetration of cooling liquid and other damages. At detection of cracks replace a head of cylinders.
2. Check deformation of the demountable plane of a head of cylinders. If the curvature of the demountable plane is revealed, then the head should be proshlifovat. If deformation of the demountable plane such is that head height after grinding will become less standard, then replace a head.
3. Check a condition of saddles of valves. In the presence of pitting (poles), cracks, traces of a progar repair of a head in a workshop of car service will be required. Insignificant defects can be removed with grinding in of the valve.
4. Check wear of the directing plugs. For this purpose insert the valve into the corresponding directing plug and shake here and there. Small, hardly notable side play is admissible.
5. If a valve side play in the plug considerable, then measure diameter of the valve. If diameter of the valve considerably decreased owing to wear, then replace the valve. If diameter of a core of the valve meets standard, then it is necessary to replace the directing plug (it is carried out in a workshop of car service).
6. If the directing plugs change, then saddles of valves should be pereshlifovat (or to perezenkovat) only after a press fitting of new plugs.

VALVES

PERFORMANCE ORDER
1. Check existence on valves of cracks, traces of a burn-out, zadir and the fillet formed owing to wear on cores. Turn of the valve check its bend. Check development of end faces. At detection of any signs of wear and damages replace the valve.
2. If as a result of this check it becomes clear that a condition of the valve satisfactory, then measure diameter of the valve in several places. Noticeable distinction of diameters indicates wear of a core of the valve. At detection of noticeable distinction of diameters at least in two places replace the valve.
3. If a condition of valves satisfactory, then them it is necessary to grind in to saddles. If on saddles there are only insignificant damages, or the saddle was exposed to regrinding, then grinding in can be executed on fine structure. The coarse pritirochny structure should be applied only in case of detection of traces of deep development or a strong burn-out of saddles. In this case the head of cylinders and valves should be handed over on check to the skilled expert to define whether it is necessary to perezenkovat saddles, or to replace inserts of saddles (if are provided).
4. Before grinding in put a head of cylinders on a plain surface, combustion chambers up.
5. Apply a thin film of pritirochny paste on a saddle facet. Carry out grinding in, turning adaptation on 180 ° in both parties and periodically raising the valve for uniform redistribution of abrasive material.
6. Grinding in on rough structure comes to an end after formation of a monotonous opaque corbel on facets of the valve and a saddle. Wipe the valve and a saddle from the remains of paste and continue grinding in on fine structure. Grinding in is considered complete at education on facets of the valve and a saddle of a uniform continuous corbel of grayish color. Further grinding in is not allowed as because of excessive development of a saddle the subsequent its repair can become impossible.
7. After the end of grinding in of all valves carefully wash out all details solvent.

DETAILS OF THE VALVATE MECHANISM

PERFORMANCE ORDER
1. Check existence on springs of traces of a vykrashivaniye and damages. A rough inspection of a condition of a spring can be carried out by comparison of length of a spring in a free state from standard.
2. Check a spring deviation from a vertical by means of a square and compare to standard.
3. If at least one of springs is damaged, has the raised deviation from a vertical, or lost elasticity, then replace all springs in a set. Keep in mind what at capital repairs of a spring of valves is recommended to be changed irrespective of their state.
4. Oil scraper caps change irrespective of their state.