Exhaust valves

TM 10-3930-634-34

ing solvent (Fed Spec P-D-680) and dry thoroughly

tly and drive the guide into the cylinder head as il-

with compressed air.

lustrated in figure 3-80.

(b) Inspect the counterbores for cleanliness, con-

CAUTION

centricity, flatness and cracks.

Do not use the valve guides as a means of

(c) Immerse the cylinder head for at least 30

turning the cylinder head over or handling

minutes in water heated to 180 F. to 200 F.

the cylinder head.

(d) Rest the cylinder head, bottom side up, on a

(4) Exhaust valves.

work bench and locate the insert squarely in the coun-

(a) An exhaust valve which is to be reused may

terbore seat, face up. Install the insert in the cylinder

be refaced, if necessary; to provide sufficient valve

strength and spring tension the edge of the valve must

while the head is still hot and the insert is at room

not be less than 1/32 inch thick.

temperature. Drive the insert into place with install-

ing tool as illustrated in figure 3-79.

(b) Before either a new or used valve is in-

(3) Exhaust valve guide. Turn the cylinder head

stalled, inspect the valve seat in the cylinder head for

right side up and install the exhaust valve guides as

proper valve seating. The proper angle for the seating

follows:

face for both valve and seat insert is 30.

(c) When a new valve seat insert is installed or

(a) Install the threaded end of valve guide in the

proper guide installation tool.

(b) Position the valve guide squarely in the bore

of the cylinder head and tap the installation tool gen-