Check

Before inspecting completely remove the cylinder head all oil deposits, remnants of the old gaskets, carbon deposits from the combustion chambers. You can use sandpaper grit of at least 100. Be careful not to damage the valve seat chamfer. After cleaning, rinse the head with solvent or gasoline to remove any remaining dirt. Clean the valves of a deposit of a thin wire brush. In the case of massive deposits, first remove its most blunt scraper or knife, and only then use a wire brush. Be careful not to damage the surface of the chamfer valves. Wash and clean the rest of the details. Inspection is carried out as follows:

- Carefully inspect the mating surface of the block cylinder head. Make sure there are no cracks or signs of burnout, paying particular attention to areas around the valve seats and the spark plug hole. Although the manufacturer and claims that the detection of small cracks and signs of burnout between the valve seats (the maximum allowable width - 0.5 mm) of the cylinder head can be used, publishing urged to seek the services of a technical tinning station performing repair / restoration of details of the engine;

- Inspect the valve seats. If there are any minor defects (chipping and burning), they can be removed during lapping valve during assembly (see. Below). Badly worn or damaged seat can be repaired with the permissible bore. This operation, which requires precision and special skills are also encouraged to carry on the profile service station;

- With a ruler and a set of shims check plane of the cylinder head, mating with both the cylinder block and the collectors. Make one dimension in the longitudinal direction on the surfaces of the joint intake and exhaust manifolds. Take several measurements across the surface of the cylinder head, on which the gasket (Fig. 2.10) to evaluate the deformation in all directions. Keep in mind that gasoline engines can restore the surface of the cylinder head by removing parts of the surface with the help of the skins. If necessary professional machining the cylinder head contact on the profile service station. Keep in mind that when this repair is required to sustain the minimum height of the cylinder head, valve seats regrinding necessary in some cases - the replacement of all valves (valves to repair size). Prior consultation on the profile service station;

- Inspect the camshaft. The surface of necks and cams should be smooth with a matte sheen.

Bluish color of the surface indicates engine overheating or his lack of lubrication. Bullies, chipping, glitter talking about wear. Accelerated depreciation begins immediately after the damage the outer layer of the camshaft, and so it is always necessary to replace the damaged parts;

- Check ignition distributor drive for the presence of backlash: the wear of gear teeth affects the ignition timing;

- With a special booth to check the camshaft runout. Its maximum value is not specified by the manufacturer, but as a guide you can use the value of 0.1 mm. If the measurement exceeds this number, it is necessary to solve the problem of replacing the camshaft;

- Install the camshaft to the cylinder head, fixing it covers the first and last bearing (on engines ABD, ABU and AEA set cover only a third of the bearing). Using a special indicator to measure axial play (Fig. 2.11);

- Measure the working air gap between the bearing journals and the camshaft seats formed bearing caps and cylinder head. The most suitable for this method - the use of the material ?�Plastigage?�. Lubricate the camshaft cover and the technological silicone grease. Cut off from the rod ?�Plastigage?� pieces of desired length, place them on the supporting shaft journal and secure it covers. Remove the flattened pieces of plastic and, comparing it with the width of the attached scale, define the working gap. Compare the obtained values of working backlashes from those in Table. 2.8, and if any of them is out of the specified tolerance, replace the camshaft and the cylinder head. Keep in mind, camshafts with oversize bearing shells can be purchased at the respective stores or get to order;

- Inspect the valves. Their rods do not have to attend a "step", a teaser. On a plate valve should be free of cracks, traces of burning. Make sure that at the end of the valve stem is no significant deterioration (such defects can be caused by faulty hydraulic tappets).

Measure micrometer thickness of each valve stem at several points along the length, the length of the check valve, the diameter of the plates and compare your results with the data presented in Table. 2.8, if necessary, replace the valves;

- Using V-shaped prism and a dial indicator, measure the radial runout of the valve disc. The manufacturer does not specify the maximum value, but the valve should be replaced if seen any significant heartbeat;

- Measure the maximum deviation between the valve guide diametrically opposite points (Fig. 2.12). If the measured value is outside the tolerance given in Table. 2.8, the valve and the directing plug should be replaced;

- Measure the length of each of the valve spring in the free state. As the manufacturer of the required value is not specified, then the only way to verify the length of the springs can be compared to the new spring;

- Check each spring for the curvature of setting it upright next to a square (Fig. 2.13). Check spring visually; if it seems deformed, replace the spring.