4.3.10. Cleaning and check of a condition of a head of cylinders
Careful cleaning of a head of cylinders and components of the valvate mechanism with the subsequent detailed check of their state will help to determine the approximate volume of the forthcoming recovery work.
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Strong overheats of the engine can lead to deformation of a head of cylinders and violation of planeness of its interfaced surface. |
Cleaning
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1. Scratch out all traces of material of old laying and sealant from the interfaced surfaces of a head of cylinders, the inlet pipeline and a final collector – try not to damage surfaces. Application of a special razmyagchitel which should impregnate previously stuck deposits will significantly facilitate work.
2. Remove all traces of a scum from walls of water channels.
3. A rigid wire brush carefully clean all available cavities and openings. At strong pollution of canals the clearing of a head should be charged to experts.
4. "Banish" the tap suitable by the size each of bolted openings, having removed corrosion products, traces of old sealant from a carving and having restored the damaged rounds. In the presence of access to a source of compressed air, blow openings, having removed from them shaving and small garbage.
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When using compressed air do not forget to put on goggles! |
5. A wire brush smooth out a carving of bolts of fastening of covers of the camshaft(s).
6. Wash out a head solvent and carefully dry it. Use of compressed air will allow to reduce significantly the term of drying and will give a quality assurance of a clearing of badly available cavities and openings.
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Different structures for removal of traces of a deposit significantly facilitating implementation of the procedure of cleaning can be got in many shops of automobile accessories. Remember that such means usually are chemically aggressive and have to be applied with observance of the appropriate measures of precaution, – strictly adhere to instructions of the manufacturers who are usually given on the label of a container. |
7. Wash out solvent of a yoke of the drive of valves and covers of bearings of the camshaft(s), then carefully dry them. Try not to mix components in the course of cleaning – you monitor marking of belonging of details to the cylinders / valves. Use of compressed air will significantly facilitate implementation of the procedure (do not forget to put on goggles).
8. Wash out in solvent and carefully dry valvate springs, their plates and crackers of cutting locks. Try not to mix components.
9. Scratch out the bulk of the valves of deposits created on surfaces, then a wire nozzle to the electric drill finally smooth out surfaces of cores and plates of valves – you watch that valves were not mixed. |
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Check of a state
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Before making the decision on need of performance of machining of a head of cylinders, make careful check of its state. Having attentively studied the material stated in the real subsection, make the list of the components needing special attention. |
Head of cylinders
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1. Attentively check a head of cylinders for existence of traces of leak of cooling liquid, cracks and other damages. The burst head is subject to replacement without fail. In case of lack of confidence in definition of a condition of a head, it is necessary to send it for check to a workshop of car service. If repair is not possible, replace a defective head.
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2. By means of the measuring instrument of planeness and the probe of lezviyny type check the interfaced head surface for existence of signs of deformation (see an accompanying illustration). If not planeness exceeds value, admissible on standards (see Specifications at the beginning of the present Chapter), the head needs to be sent to a pro-point in a mechanical workshop. |
3. Check a condition of saddles of valves in each of combustion chambers. In case of identification of cavities, cracks, traces of a progar, the head should be subjected to special recovery repair which performance lies outside qualification of the average amateur mechanic and it has to be entrusted to specialists of car service.
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4. By means of the DTI measuring instrument estimate the size of a side play of cores of valves in the directing plugs (see an accompanying illustration). The valve has to be raised over a saddle approximately on 1.6 mm. It is necessary then to divide the full size of a side beating of the valve into two to define a gap of landing of the valve in the directing plug. Compare results of the made calculations to requirements of Specifications. In the presence of doubts in correctness of definition of a condition of components, their check should be charged to experts of a workshop of car service.
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Valves
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1. Attentively check the working surfaces of valves for existence of signs of uneven wear, deformations, cracks, cavities and traces of a progar. Estimate extent of operation of cores of valves. Check whether there are no cracks in necks of cores. By rotation check valves for a bend of cores. Make sure of lack of cavities and signs of excessive wear of end faces (see an accompanying illustration). Identification of any of the listed defects demands delivery of valves for recovery repair in a workshop of car service. |
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2. Measure width of a cylindrical part (corbel) of a plate of each of valves (see an accompanying illustration). If width of a corbel appears less than the value stipulated in Specifications, replace the valve. |
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Components of valves
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1. Estimate degree of wear of face parts of each of valvate springs, check springs for existence of cavities. Measure the free length of springs (see an accompanying illustration) and compare results of measurements to requirements of Specifications. If the spring is shorter than the lower admissible limit, it is sunk and is subject to replacement. Check also for compliance to standard requirements of effort, developed by springs (this work it is better to charge to experts of a workshop of car service). |
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2. Establishing each of springs vertically on a flat surface, check severity of their tortsovka (see an accompanying illustration). The springs with violation of a tortsovka as well as which sank are subject to replacement. |
3. Check plates of springs and crackers of their cutting locks for existence of cracks and signs of wear. All details which are in a doubtful state should be replaced new in order to avoid development of defects in the future.
4. At considerable degree of wear of components of valves that is quite probable for the engine needing capital repairs, collect valvate assemblies, establish them on the regular places in a head and you pass to performing procedures of service of valves (see Service of valves). |
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