Caution! Reassembling and inspecting the cylinder head requires special tools and parts that you may not have. Therefore, if you are an amateur, it will be much more economical to buy a new head than to waste time on overhauling and repairing the old one.
Bulkhead
1. Remove the cylinder head, camshafts and valve lifters.
2. Before removing the valves, prepare separate numbered bags to contain the valves and their corresponding parts.
3. Compress the first valve spring and remove the clips with pliers. Remove the spring plate, spring and spring seat.
4. Remove the valve from the head and remove the valve stem seal from the guide bushing. If the valve does not pass through the guide bushing, clean the edges of the valve stem end with sandpaper.
5. Repeat the same procedure with the remaining valves.
6. Once you have disassembled the head, it needs to be cleaned and checked.
Cleaning
1. Clean all traces of old gaskets from the head surfaces and wipe it with solvent.
2. Clean out any deposits that have formed in the internal passages and holes of the head. If rust deposits have blocked the water passages of the cylinder head, contact a specialist.
3. Using a suitable tap and compressed air, clean the threads in the head bolt holes.
4. Brush the threads of the intake and exhaust manifold dowel pins.
5. Rinse the head in solvent and dry it.
6. Wash the valves and their components in solvent. Dry all parts.
Examination
Valve inspection areas
1. Valve stop
2. Spring retainer grooves
3. Valve stem
4. Valve chamfer
5. Valve edge
6. Exhaust valve
7. Inlet valve
1. Inspect the head for cracks, signs of coolant leakage, and other damage. If cracks are detected, the head must be machined; if the damage is too severe, the head must be replaced.
2. Using a ruler and feeler gauge, check the deformation of the mating surfaces of the head. If the deformation exceeds the permissible limits, the head must be processed in a specialized workshop.
3. Inspect the valve seats, if they are damaged, contact a specialist.
4. Measure the clearance between the valve stem and the guide bushing using a measuring instrument. The device readings must be divided by two and you will get the gap size. If the clearance exceeds the permissible limits, the valve guide bushing must be replaced.
Valves
5. Inspect the valve faces for wear, deformation, cracks, burns, and other damage. Check the valve stems for wear and cracks. Check that the rods are not bent. If any damage is detected, the valves must be treated in a specialized workshop.
6. Measure the width of the valve edge. If the obtained value is less than the permissible limits, the valve must be replaced.
Valve elements
7. Inspect the valve springs for wear or damage. Measure the length of the springs. If the length of any spring is less than the specification limit, replace it.
8. Check that the springs are straight. Replace deformed springs if necessary.