REMOVAL & INSTALLATION
A valve spring compressor is needed to remove the valves and springs; these are available at most auto parts and auto tool shops. A small magnet is very helpful for removing the keepers and spring seats.
- Remove the cylinder head, using the proper procedures and set the head on its side on a bench.
- Install the spring compressor so that the fixed side of the tool is flat against the valve head in the combustion chamber, and the screw side is against the retainer.
- Slowly turn the screw in towards the head, compressing the spring. As the spring compresses, the keepers will be revealed; pick them off of the valve stem with the magnet as they are easily lost.
- When the keepers are removed, back the screw out and remove the retainers and springs. Note how they came off so they are reinstalled the same way. Remove the compressor and pull the valves out of the head from the other side. Remove the valve seals by hand and remove the spring seats with the magnet.
- Oil each valve stem, and install each valve into the head in the reverse order of removal, so that all parts except the keepers are assembled on the stem. Always use new valve stem seals.
- Install the spring compressor, and compress the retainer and spring until the keeper groove on the valve stem is fully revealed. Coat the groove with a wipe of grease (to hold the keepers until the retainer is released) and install both keepers, wide end up.
- Slowly back the screw of the compressor out until the spring retainer covers the keepers. Remove the tool. Lightly tap the end of each valve stem with a rubber hammer to ensure proper fit of the retainers and keepers.
Before the valves can be properly inspected, the stem, lower end of the stem and the entire valve face and head must be cleaned. An old valve works well for chipping carbon from the valve head, and a wire brush, gasket scraper or putty knife can be used for cleaning the valve face and the area between the face and lower stem. Do not scratch the valve face during cleaning. Clean the entire stem with a rag soaked in thinners to remove all varnish and gum.
Thorough inspection of the valves requires the use of a micrometer, and a dial indicator is needed to measure the inside diameter of the valve guides. Measure the diameter of each valve stem in several locations. Jot these measurements down. Using a dial indicator, measure the inside diameter of the valve guides at their bottom, top and midpoint 90° apart. Jot these measurements down also. Subtract the valve stem measurement from the valve guide inside measurement; if the clearance exceeds that listed in the engine rebuilding specifications chart, replace the valve(s) or valve guide(s).
Check the top of each valve stem for pitting and unusual wear due to improper rocker adjustment, etc. The stem tip can be ground flat if it is worn, but the minimum valve length or longer must be maintained.
If inspection reveals that the valve is usable, then it can be resurfaced. The valve grinding wheels must be dressed and the proper valve refacing angles must be achieved (See specifications). Only remove enough material to eliminate pits, grooves or to correct any runout.
If the valve stem tips are ground, make sure you fix the valve securely into a jig designed for this purpose, so the tip contacts the grinding wheel squarely at exactly 90°. Most machine shops that handle automotive work are equipped for this job.
The valve seats can be cleaned, using a carbide cutter. The proper angle must be achieved and, again, only enough material should be removed to eliminate grooves or pitting. After the valve and seat have been resurfaced, the contact area should be checked, using white lead or Prussian blue.
After the engine is reassembled, it will be necessary to check the valve clearance on engines except the 2S-E, which has hydraulic lifters. See Section 2 .