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Valves and Valve Springs

REMOVAL & INSTALLATION

1,586cc, 1,796cc, 1,970cc, 1,998cc and 2,209cc Engines

Fig. 1: Use a valve spring compressor tool to relieve spring tension from the valve caps

Fig. 2: A magnet may be helpful in removing the valve keepers

Fig. 3: Remove the spring from the valve stem in order to access the seal

Fig. 4: Remove the valve stem seal from the cylinder head

Fig. 5: Invert the cylinder head and withdraw the valve from the cylinder head bore

Fig. 6: A wire wheel may be used to clean the combustion chambers of carbon deposits

Fig. 7: A dial gauge may be used to check valve stem-to-guide clearance

Fig. 8: Valve stems may be rolled on a flat surface to check for bends

Fig. 9: With the valve spring out of the way, the valve stem seals may now be replaced

Fig. 10: Use a caliper gauge to check the valve spring free-length

Fig. 11: Check the valve spring for squareness on a flat service; a carpenter's square can be used

Fig. 12: The valve spring should be straight up and down when placed like this

Fig. 13: Use a micrometer to check the valve stem diameter

Fig. 14: Check the cylinder head for flatness across the head surface

Fig. 15: Checks should be made both straight across the cylinder head and at both diagonals

Fig. 16: View of critical valve dimensions

Fig. 17: Using a valve grinding machine to re-face an engine valve

Fig. 18: Example of a homemade valve lapping tool

Fig. 19: Using a hand lapping tool to lap valves

Fig. 20: Example of the marks seen on the valve tips for valves with rotators

Fig. 21: Testing the valve spring pressure

Fig. 22: Measuring valve spring installed height — the measurement is taken from the spring seat (cylinder head), to the top of the spring (bottom edge of the spring retainer)

Fig. 23: Measure the springs' free length — there should be no more than 5/64 inch (0.078 inches) variation between springs

Fig. 24: View of the valve and spring components — not shown are the valve keepers, which sit in the center of the retainer and lock around the valve

Fig. 25: View of a typical valve seal — be sure to push the new seal firmly over the valve guide

Fig. 26: Using a valve guide driver to install a new valve guide into the head

Fig. 27: Checking valve seat concentricity

  1. Remove the cylinder head. On the diesel and the 1,998cc, remove the rocker shaft assembly. On the 1,998cc, lift out the camshaft.
  2. Remove the deposits from the combustion chambers with a stiff wire brush and scraper before removing the valves. Do not scratch the cylinder head surface.
  3. Compress the valve springs with a valve spring compressor. Remove the valve spring retainer locks and release the springs.
  4. Fabricate a valve arrangement board to use when you remove the valves, which will indicate the port in which each valve was originally installed. Also note that the valve keys, caps, etc. should be arranged in a manner which will allow you to install them on the valve on which they were originally used.
  5. Remove and discard the valve seals. On models using the umbrella type seals, note the location of the large and small seals for assembly purposes.
  6. Thoroughly clean the valves on the wire wheel of a bench grinder, then clean the cylinder head mating surface with a soft wire wheel, a soft wire brush, or a wooden scraper. Avoid using a metallic scraper, since this can cause damage to the cylinder head mating surface, especially on models with aluminum heads.
  7. Using a valve guide cleaner chucked into a drill, clean all of the valve guides.
  8. Install each valve into its respective port (guide) of the cylinder head.
  9. Mount a dial indicator so that the stem is at 90°to the valve stem, as close to the valve guide as possible.
  10. Move the valve off its seat, and measure the valve guide-to-stem clearance by rocking the stem back and forth to actuate the dial indicator.
  11. Measure the valve stems using a micrometer, and compare to specifications, to determine whether stem or guide wear is responsible for excessive clearance.

    NOTE: Consult the Specifications tables earlier in this chapter.

  12. Check the cylinder head flatness as described under Cylinder Head Removal and Installation.

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