DETROIT DIESEL 53
Cylinder Head 1.2
up with crocus cloth wet with fuel oil. If the bores are
excessively scored or worn so that the cam follower-to-
head clearance exceeds .006", replace the cylinder
4. Inspect the valve seat inserts for cracks or burning.
Also, check the valve guides for scoring.
5. Check the water nozzles*
Be sure they are not loose. Water nozzles are used
only in the passages between the cylinders.
necessary, install or replace the water nozzles as
a. Be sure the water inlet ports in the bottom of the
head are clean and free of scale. The water
holes may be cleaned up with a 5/8" diameter
drill. Break the edges of the holes slightly.
Fig. 5. - Correct Installation of Water Nozzles
b. If the water holes in the head have been
in Cylinder Head
enlarged by corrosion, use a wooden plug or
2. Exhaust valves and springs (Section 12.2).
other suitable tool to expand the nozzles so that
they will remain tight after installation.
3. Install the fuel injectors at this time or after
c. Press the nozzles in place with the outlet holes
installing the cylinder head (Section 2.1.1).
positioned as shown in Fig. 5. The angle
4. Cam followers, cam follower guides, push rod
between the outlet holes in the nozzle is 90.
assemblies, rocker arm shafts and rocker arms; do not
Press the nozzles from flush to 1/32" below the
tighten the rocker arm bracket bolts at this time (Section
bottom surface of the cylinder head.
6. Inspect the parts removed from the cylinder head
5. Place new washers on the fuel connectors, then
before they are reinstalled in the old head or transferred
install the fuel connectors and tighten them to 20-28 lb-ft
to a new cylinder head.
Assemble Cylinder Head
New service cylinder heads include valve guides, valve
Perform the following inspections just prior to installing
seat inserts, water nozzles, injector tubes and the
the cylinder head on the engine.
1. Check the cylinder liner flange height as outlined in
CAUTION: When installing the plugs in the
sealant merchandized as a "dual purpose
2. Check to be sure the tops of the pistons are clean
sealer" to .the threads of the plugs only.
and free of foreign material.
Work the sealant into the threads and wipe
off the excess with a clean, lint-free cloth so
3. Check to see that each push rod is threaded into the
that the sealant will not be washed into the
clevis until the end of the push rod projects through the
fuel system and result in damage to the
clevis. This is important since serious engine damage
will be prevented when the crankshaft is rotated during
When a new cylinder head is to be used, remove) the
parts listed below from the old head and install them in
4. Check to be sure that the groove and the
the new head. If the old cylinder head is to be reused,
counterbores in the top of the cylinder block are clean
install the parts in the old head prior to assembling the
head on the cylinder block.
1970 General Motors Corp.
SEC. 1.2 Page 5