Attention! 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 spend time overhauling and repairing the old one.
Bulkhead
1. Remove the cylinder head, camshafts and valve lifters.
2. Before removing the valves, prepare individual numbered bags to hold the valves and their respective parts.
3. Compress the first valve spring and remove the retainers 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 valve guide. If the valve does not pass through the guide sleeve, sand the edges of the end of the valve stem with sandpaper.
5. Do the same for the rest of the valves.
6. After you have disassembled the head, it must be cleaned and checked.
Cleaning
1. Clean all traces of old gaskets from the surfaces of the head and wipe it with solvent.
2. Clean deposits formed in the internal channels and holes of the head. If rust deposits have blocked the water channels of the 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 dowel pins on the intake and exhaust manifolds.
5. Wash the head in solvent and dry it.
6. Wash the valves and their elements in solvent. Dry all parts.
Examination
Valve Test 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, coolant leaks, and other damage. If cracks are found, the head must be machined, if the damage is too severe, the head must be replaced.
2. Using a ruler and a feeler gauge, check the deformation of the mating surfaces of the head. If the deformation exceeds the allowable 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 guide sleeve with a gauge. The readings of the device must be divided by two and you will get the gap value. If the clearance exceeds the allowable limits, the valve guide must be replaced.
Valves
5. Inspect the valve bevels for wear, distortion, cracks, burn marks, and other damage. Check valve stems for chafing and cracks. Check if the stems are bent. If any damage is found, the valves must be processed in a specialized workshop.
6. Measure the valve lip width. If the value obtained is less than acceptable limits, the valve must be replaced.
Valve elements
7. Inspect the valve springs for wear and damage. Measure the length of the springs. If any spring is less than the specification limit, replace it.
8. Check that the springs are straight. Replace deformed springs if necessary.