b. Use the measurements obtained and the limits
given in Table 1 as a guide to determine the
advisability of reinstalling the head on the engine or of
refacing it. The number of times a cylinder head may
be refaced will depend upon the amount of stock
c. If the head is to be refaced, remove the injector
tubes prior to machining. Do not remove more metal
from the fire deck of any cylinder head below the
minimum distance of 4.376 inches (Fig. 4).
Figure 3. Checking Bottom Face of Cylinder Head
When a cylinder head has been refaced, critical dimensions such as the protrusion of valve seat
inserts, exhaust valves, injector tubes, and injector spray tips must be checked and corrected. The
push rods must also be adjusted to prevent the exhaust valves from striking the pistons after the
cylinder head is reinstalled in the engine.
Install new injector tubes (Injector Tube) if the old tubes leaked or the cylinder head was refaced.
Inspect the exhaust valve seat inserts and valve guides (Exhaust Valves).
Inspect the cam follower bores in the cylinder
head for scoring or wear. Light score marks may be
cleaned up with crocus cloth wet with fuel oil. Measure
Record and compare the readings of the followers and
bores to determine the cam follower-to-bore clearances.
The clearance must not exceed 0.006-inch with used
parts (refer to Specifications).
If the bores are
excessively scored or worn, replace the cylinder head.
Figure 4. Minimum Distance Between Top and
Bottom Faces of Cylinder Head