C y l i n d e r Head 1.2
DETROIT DIESEL 53
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
head.
4. Inspect the valve seat inserts for cracks or burning.
Also, check the valve guides for scoring.
5. Check the water nozzles in a four-valve cylinder
head to be sure they are not loose. Water nozzles are
used only in the passages between the cylinders. If
necessary, install or replace the water nozzles as
follows:
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 enlarged
in Four-Valve Cylinder Head
by corrosion, use a wooden plug or other suitable
tool to expand the nozzles so that they will remain
2. Exhaust valves and springs (Section 1.2.2).
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 (Sections 2.1 or 2.1.1).
positioned as shown in Fig. 5. The angle between
the outlet holes in the nozzle is 90o. Press the
4. Cam followers, cam follower guides, push rod
nozzles from flush to 1/32" below the bottom
assemblies, rocker arm shafts and rocker arms; do not
surface of the cylinder head.
tighten the rocker arm bracket bolts at this time
(Section 1.2.1).
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
install the fuel connectors and tighten them to 20-28
transferred to a new cylinder head.
lb-ft torque.
Assemble Cylinder Head
Pre-Installation Inspection
New service cylinder heads include valve guides, valve
Perform the following inspections just prior to
seat inserts, water nozzles, injector tubes and the
installing the cylinder head on the engine.
necessary plugs.
1. Check the cylinder liner flange height as outlined in
CAUTION: When installing the plugs in the fuel
Section 1.6.3.
manifolds, apply a small amount of sealant
merchandized as a "dual purpose sealer" to the
threads of the plugs only. Work the sealant into
2. Check to be sure the tops of the pistons are clean
the threads and wipe off the excess with a clean,
and free of foreign material.
lint-free cloth so that the sealant will not be
washed into the fuel system and result in
3. Check to see that each push rod is threaded into the
damage to the injectors.
clevis until the end of the push rod projects through
the clevis. This is important since serious engine
When a new cylinder head is to be used, remove the
damage will be prevented when the crankshaft is
parts listed below from the old head and install them
rotated during tune-up.
in the new head. If the old cylinder head is to be
reused, install the parts in the old head prior to
4. Check to be sure that the groove and the
assembling the head on the cylinder block.
counterbores in the top of the cylinder block are clean
and smooth.
1. Exhaust manifold studs.
July, 1970 SEC. 1.2 Page 5
