Inspection and Reconditioning (Rev 1/97)
52
deck. The standard distortion is .002 in. (0.05 mm). The
wear limit is .006 in. (0.15 mm). Resurface or replace
the head if the distortion exceeds the wear limit.
Disassembly
1. Use a valve spring compressor to remove the valve
keepers.
2. Remove the valve spring retainers, the valve springs,
and the valves. Mark each valve or keep them in order
so they can be returned to their original positions when
assembled.
3. Remove the valve stem seals and boil out the head if
possible.
Valve Guides
1. Remove the carbon from the valve guides with a valve
guide carbon beater.
2. Measure the inside diameter of the valve guides with a
small hole gauge or a graduated set of tapered pilots. If
the valve guides are larger than the wear limits (refer to
Specifications), replace the valve guides.
NOTE: If the engine has been in use for some time
and has accumulated many hours of running time, it
is advisable to replace the valve guides because they
usually show significant wear after numerous hours
of service. Because the valve seat grinding procedure
is centered by a pilot placed in the valve guide, new
straight valve guides allow the valve seats to be
ground accurately.
3. Remove the valve guides by using a valve guide tool
and a press or a hammer to drive the valve guides out
through the bottom of the cylinder head.
4. Install the new valve guides using the valve guide tool
and a press or a hammer. Drive the valve guide into the
top of the cylinder head until the valve guide projection
(the distance between the top of the valve guide and the
top of the valve spring seat) is correct. Refer to Specifi-
cations for the recommended valve guide projections.
Removing or Installing Valve Guides
Valve Guide Projection
5. After installation, ream the new valve guides. Use a
ream that matches the smallest standard dimension for
the inside diameter of the valve guides (refer to Specifi-
cations).
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