1.2 Cylinder Head
DETROIT DIESEL 53
b. Install dummy or scrap injectors- to ensure seating
of the injector tubes. Dummy injectors may be made
from old injector nuts and bodies - the injector spray tips
are not necessary. Tighten the injector clamp bolts to 20-
c. Drill and tap into one of the water hole cover plates
for an air hose connection and apply 80-100 psi air
pressure to the water jacket. Then, immerse the head in
a tank of water previously heated to 180-2000F. for
twenty minutes to thoroughly heat the cylinder head.
Observe the water in the tank for bubbles indicating
cracks or leaks.
d. Remove the cylinder head from the tank and dry it
with compressed air.
e. If inspection revealed cracks, replace the cylinder
Replace any leaking injector tubes as outlined in
Over a prolonged period of operation, the cylinder head
may assume a contour to match that of the cylinder
block, which is normal. However, if the cylinder head is
allowed to become overheated because of coolant loss,
the resultant high temperatures cause stresses to occur
in the casting which will affect the flatness of the head.
2. Check the bottom (fire deck) of the cylinder head for
flatness as follows:
Fig. 3 - Checking Bottom Face of Cylinder Head for Warpage
Use an accurate straightedge and feeler gage J 3172 to check for transverse warpage at each end and
between all of the cylinders. Also, check for longitudinal warpage in six places as shown in Fig. 3. Maximum
allowable warpage is given in the following chart:
b. The maximum allowable warpage limits should be used as a guide in determining the advisability of
reinstalling the head on the engine or of refacing it. The number of times a cylinder head may be refaced will, of course,
depend upon the amount of stock removed from the head during previous reworking operations.
If the cylinder head is to be refaced, remove the injector tubes prior to machining. Not over .020" of metal
should be removed from the fire deck of the cylinder head.
The distance from the top to the bottom (fire deck) of the
cylinder head must not be less than 4.376", as shown in
(Fig. 4). Stamp the amount of stock removed on the face of
the fire deck near the outer edge of the head, in an area not
used as a sealing surface.
After a cylinder head has been refaced and new injector
pressure check the cylinder head as outlined in Step 1.
Fig. 4 - Minimum Distance Between Top and
Bottom Faces of Cylinder Head
Inspect the cam follower bores in the cylinder head for scoring or wear. Light score marks may be cleaned