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Removal of sludge, grinding valves and restoration of cylinder heads
| - The removal of the cylinder head and remove carbon deposits deposits from the surfaces of the combustion chambers and holes using a blunt scraper. Clean the cylinder head from the dross, residues of the old gasket or sealing paste. Rinse the head with kerosene and be sure to pull a piece of cloth over the windows and bolt holes of the cylinder head, as dirt particles remaining in the depressions, can reach the surface of the gasket or cylinder during its installation and lead to leaks after assembly.
- If you clean the cylinder head coolant leak is detected, check the deformation on the head. For this purpose, use a ruler and probes or mirror glass. If the curvature of the surface of greater than 0.08 mm, restore the surface of the head shlifovaniem.Prosledite to ensure that the minimum distance between the plate and the surface of the valve gasket to satisfy the specifications.
- Clean the pistons and the upper part of the cylinder bores. If the pistons are still in the unit, be careful to avoid getting soot particles into the cylinders, as This can scratch their walls, pistons and damage the ring. Rotate the crankshaft and clean the soot from the rest of the pistons and cylinder bores.
- Carefully remove soot particles from the cylinder bores, and then pour a little oil around the edges of the liquid piston to lubricate the piston rings.
- Inspect the valve plate (especially the final), make sure that there are no pitting and erosion. At the same time check the valve seats. If the saddle is only slightly burned, the defects can be eliminated by simultaneous lapping valves and their saddles first coarse, then fine lapping paste. With much spalled valve seats they need to be re-grind until the seat cone angle of 45 ?�. The valves are usually much wear and burn, so they should be replaced, and grind the seats.
- For lapping valves apply a little rough carborundum composition on the valve seat, and set the "lapping" with a suction cup on the valve head. Turn the "lapping" alternately 180 ?�, grind the valve to the seat plate, occasionally lifting the valve to redistribute the lapping compound. When the valve seat and will smooth satin strip, remove the part and repeat the grinding with a fine carborundum composition by turning and lifting the valve, as described above. When the valve on the saddle will smooth continuous light gray strip lapping operation can be considered complete.
- Remove any carbon deposits from the head and the valve stem. Thoroughly clean them from lapping composition, carefully taking care not to leave its traces in the channels and in directing plugs of valves. Clean the valves and seats, first with rags soaked with kerosene, then with a dry cloth and Blow valves, guides and channels.
- To check the wear of the valve guide insert the new not worn valve and check whether it sways from side to side. If rocks, remove the guide sleeve from the cylinder head using a mandrel. The outer diameter of the guide a higher amount (0.012 mm) to maintain its interference fit in the cylinder head. Before installing the guide, heat cylinder head to 80-90 ?�, and directing cool in liquid nitrogen or dry ice, if possible. Insert the guide so that the spring split ring smoothly against the upper surface of the cylinder head.
- Check the length of the valve spring in the free state, comparing it with a new spring, and replace them if necessary.
- Check crackers plates of springs, where they exist, and, if necessary, replace them.
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