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