TM 5-3810-300-24&P-3
1.2 Cylinder Head
If a service replacement cylinder head is to be installed,
excessively scored or worn, replace the cylinder head.
it must be thoroughly cleaned of all rust preventive
compound, particularly inside the integral fuel manifolds,
6. Check the water hole nozzles to be sure they are
before installing the plugs. A simple method of removing
not loose. If necessary, replace the nozzles as follows:
the rust preventive compound is to immerse the head in
solvent, oleum or fuel oil, then scrub the head and go
through all of the openings with a soft bristle brush. A
NOTE: Early engines did not incorporate water
suitable brush for cleaning the various passages in the
nozzles in the cylinder head.
It is
head can be made by attaching a 1/8" diameter brass
recommended that nozzles be installed when
rod to brush J 8152. After cleaning, dry the cylinder
an early engine is in for a regular overhaul or for
head with compressed air.
reconditioning of the cylinder head.
A service replacement cylinder head includes the
a.
Remove the old nozzles.
exhaust valve guides, valve seat inserts, water nozzles,
b.
Make sure the water inlet ports in the cylinder head
injector tubes, pilot sleeves, bridge guides, valve spring
are clean and free of scale. The water holes at
seats and the necessary plugs. In addition, studs, cover
each end of the head may be cleaned up with a 1/2"
plates, gaskets, lock washers and nuts are provided to
drill and the intermediate holes may be cleaned up
seal the water outlet openings that are not required on
with a 13/16" drill. Break the edges of the holes
certain engines. A length of flexible fuel hose and fittings
slightly.
are also included where required.
c. For the positioning of the nozzles in a four-valve
cylinder head, refer to Fig. 13. Press the nozzles
Injector clamp bolts or studs are not included and it is
flush to .0312"recessed below the surface of the
necessary to use new parts or transfer the old parts to
cylinder head.
the new head. Injector clamp bolts are interchangeable
d. Check to make sure the nozzles fit tight. If
with the former studs and nuts; the special washer is
necessary, use a wood plug or other suitable tool to
used with either the bolt or stud.
expand the nozzles, or tin the outside diameter with
solder to provide a tight fit. If solder is used, make
CAUTION: When replacing a former cylinder
sure the orifices in the nozzles are not closed with
head equipped with separate fuel manifolds by
a current head, a reversal of fuel flow through
7. Replace broken or damaged studs. Apply sealant
the injectors may occur. Replace the injector
to the threads of new studs and drive them to 10-25 lb-ft
fuel filters to prevent foreign matter in the old
(14-34 Nm) torque (water manifold cover studs) or to 25-
filters from entering the injectors.
40 lb-ft (34-54 Nm) torque (exhaust manifold studs).
Assemble Cylinder Head
8. Pilot sleeves have been added to the head
After cleaning and inspection, assemble the cylinder
mounting bolt holes at each end of the four-valve cylinder
head as follows:
heads (on the camshaft side on current heads or
1. Install the necessary plugs and tighten them to the
exhaust side of former heads). Make sure the sleeves
specified torque (Section 1.0). Drive headless plugs
are flush or recessed below the fire deck of the cylinder
flush to .0625" below the surface of the cylinder head.
head: Replace damaged sleeves. Pilot sleeves can be
The 3/8" socket head oil gallery plug, at each end of the
installed on early cylinder heads by reaming the end bolt
head, must not protrude more than .0625", and a .2187"
holes (camshaft side of head) to .687 " /.688" diameter
diameter rod placed in the vertical oil feed hole must
by .750" deep and pressing the sleeves flush or slightly
pass the inner face of the plug.
recessed below the fire deck. The sleeves, which act as
CAUTION: Apply a small amount of "dual
a hollow dowel to provide a closer fit between the
purpose" sealer to the threads of the plugs
mounting bolts and the cylinder head, help to guide the
only. Work the sealant into the threads and
head in place without disturbing the seals and gaskets.
wipe the excess with a clean lintless cloth so
9. Inspect all other components removed from the
that
cylinder head.
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