ASf03045
Figure 3-45.--Valve spring compressors for L-head and valve-in-head engines.
After you have cleaned the valves, remove the
compressor (fig. 3-45). Next, clean the valves with a
carbon from the intake and exhaust valve ports. Inspect
wire brush or buffing wheel (fig. 3-46). When using the
closely around the valve ports and cylinders of the
buffing wheel, make sure you wear proper eye
block for cracks and faulty valve seats. Should cracks
protection to prevent wire and other foreign matter
be found, check with your supervisor for the proper
from flying into your eyes.
procedure to follow. After you inspect the cylinder head
Be careful not to interchange the valves. Each valve
for cracks, check the head for warpage, using a
must be replaced in the same valve port from which it
straightedge and a thickness gauge. The water passages
was removed. The valve stem moving up and down in
inside the head should be cleaned if an excessive
the valve guide develops a wear pattern. And, if the
buildup of scale and rust is found. The easiest method is
valves are interchanged, a new wear pattern is
to remove the core plugs and boil the head in a cleaning
developed, causing excessive wear on the valve stem
solution. The alternate method is to scrape the
and guide.
unwanted material loose and then flush with water, air,
To eliminate any confusion, you should devise
or a combination of both. After a thorough inspection
some system of marking the valves to identify them
of the parts, the next step is to resurface the valve face
with the cylinders from which they were taken. The
with a valve refacing machine (fig. 3-47). Clamp the
most common way to identify valves is to place them in
valve stem in the chuck of the refacing machine. Be
a piece of board with holes drilled and numbered to
sure the grinding angle index is set to the angle of the
correspond with the cylinder the valves came from. If
valve head you are about to grind. Follow the operating
any valves are found to be worn or damaged beyond use
instructions of the manufacturer of the refacing
during inspection, replace them with new ones from the
parts room.
ASf03046
ASf03047
Figure 3-46.--Cleaning a valve with a wire buffing wheel.
Figure 3-47.--Valve refacing machine.
3-35
