Basic Engine
When a cylinder head is removed because of gasket
leaks, check the flatness of the cylinder head gasket
surface (Figure 11) for conformance to specifications. If
necessary to refinish the cylinder head gasket surface, do
not plane or grind off more than 0.010 inch.
FIG 13 Checking Valve Stem Clearance
FIG. 11 Typical Cylinder Head Flatness
FIG. 12 Checking Valve Seat Runout
Check the valve seat runout with an accurate gauge
(Figure 12). Follow the instructions of the gauge
FIG 14 Checking Valve Spring Pressure
manufacturer. If the runout exceeds the wear limit, reface
the valve and valve seat. Measure the valve seat width
Check the springs for proper pressure (Figure 14) at
(Figure 4). Reface any valve seat whose width is not
the specified spring lengths (Tool 6513-DD). Manually
within specifications.
rotating the valve spring assemblies while installed in
Inspect the valve face and the edge of the valve head
the engine must not be used to determine good
for pits, grooves or other damage. Inspect the stem for a
and/or bad valve springs. Weak valve springs cause
bent condition and the end of the valve head for pits,
poor engine performance. Replace any spring not within
grooves, scores or other wear. Inspect the stem for a bent
specifications.
condition and the end of the stem for grooves or scores.
Check each spring for squareness using a steel
Check the valve head for signs of burning, erosion,
square and a flat surface (Figure 15). Stand the spring
warpage and cracking. Minor pits, grooves, etc., may be
and square on end on the flat surface. Slide the spring up
removed. Discard valves that are severely damaged.
to the square. Revolve the spring slowly and observe the
Inspect the valve spring, valve spring retainers, locks
space between the top coil of the spring and the square.
and sleeves for wear or damage. Discard any visually
The out-of-square limits are 5/64 inch.
damaged parts.
Follow the same procedure to check new valve
Check the valve stem to valve guide clearance of
springs before installation. Make certain the proper spring
each valve in its respective valve guide with the tool
(color coded) is installed.
shown in Figure 13 or its equivalent. Use a flat end
indicator point.
HYDRAULIC VALVE LIFTERS
Install the tool on the valve stem until it is fully seated,
The valve lifter assemblies should be kept in proper
and tighten the knurled set screw firmly. Permit the valve
sequence so that they can be installed in their original
to drop away from its seat until the tool contacts the upper
position. Inspect and test each lifter separately so as not
surface of the valve guide.
to intermix the internal parts. If any part of the lifter
Position the dial indicator with its flat tip against the
assembly needs replacing, replace the entire
center portion of the tool's spherical section at
assembly.
approximately 90 degrees to the valve stem axis. Move
the tool back and forth in line with the indicator stem. Take
Cleaning
a reading on the dial indicator without removing the tool
Thoroughly clean all the parts in cleaning solvent and
from the valve guide upper surface. Divide the reading by
wipe them with a clean, lint-free cloth.
two. the division factor for the tool.
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