Fig. 9. Removing Valve Seat Insert
Inspect the valve seat inserts for excessive wear,
pitting, cracking or an improper seat angle. The proper
angle for the seating face of the valve is 30 ° and the
angle for the insert is 31 °.
Fig. 10. Installing Valve Seat Insert
The valve seat inserts are pressed into the cylinder
head and must be removed as outlined in the following
1. Clean the valve seat insert counterbores in the
procedure to avoid damage to the cylinder head:
cylinder head with trichloroethylene or other suitable
solvent. Also wash the valve seat inserts with the same
1. Place the cylinder head on its side as shown in Fig.
solvent. Dry the counterbores and the inserts with
2. Place the collet of tool J 4824-03 inside of the valve
2. Inspect the counterbores in the cylinder head for
seat insert so that the bottom of the collet is flush with
cleanliness, concentricity, flatness and cracks. The
the bottom of the insert.
counterbores in a two-valve cylinder head have a
diameter of 1.626 " to 1.627 " and a depth of .3705 " to
3. Hold the collet handle and turn the T handle to
.3845". The counterbores must be concentric with the
expand the collet cone until the insert is held securely by
valve guides within .003" total indicator reading. Valve
seat inserts which are .010" oversize on the outside
diameter are available, if required.
4. Insert the drive bar of the tool through the valve
3. Immerse the cylinder head for at least thirty minutes
in water heated to 180-200 °F (82-93 °C).
5. Tap the drive bar once or twice to move the insert
about 1/16 " away from its seat in the cylinder head.
4. Rest the cylinder head, bottom side up, on a bench
and place an insert in the counterbore valve seat side
6. Turn the T handle to loosen the collet cone and
up. Install the insert in the cylinder head while the head
move the tool into the insert slightly so the narrow flange
is still hot and the insert is at room temperature,
at the bottom of the collet is below the valve seat insert.
otherwise installation will be difficult and the parts may
7. Tighten the collet cone and continue to drive the
insert out of the cylinder head.
5. Drive the insert in place with installer J 1736 as
shown in Fig. 10 until it seats solidly in the cylinder
In place of the above procedure, a
new cam operated insert remover J
6. Check the valve seat inserts for concentricity in
23479-15 and collet J 23479-9 can be
relation to the valve guides as outlined below.
seat insert from the cylinder head.