DETROIT DIESEL 53
Cylinder Head 1.2
and the other end hooked around a control tube bracket,
6. The cylinder head must be gradually and uniformly
tighten the bracket bolts to 10-12 lb-ft torque.
drawn down against the gaskets and seals to ensure a
good seal between the cylinder head and the block.
13. After tightening the bolts, revolve the tube and see if
Therefore, it is vitally important that the cylinder head be
the return spring pulls the injector racks out (no-fuel
installed with the utmost care.
position) after they have been moved all the way in (full-
7. Then, begin on the camshaft side of the head to
fuel position). Since the injector control tube is mounted
take up the tension in the cam follower springs by
in self-aligning bearings, tapping the tube lightly with a
tightening the bolts lightly. Finally tighten the bolts to
soft hammer will remove any bind that exists. The
170-180 lb-ft torque with a torque wrench, about one-
injector racks must return to the no-fuel position freely
half turn at a time, in the sequence shown in Fig. 6.
by aid of the return spring only. Do not bend the return
Under no circumstances should the torque exceed the
spring to bring about this condition.
specified limits, otherwise the bolts may become
stretched beyond their elastic limits.
14. Install the fuel rod and the fuel rod cover (if used).
8. Cover the oil drain holes in the cylinder head to
prevent foreign objects from falling into the holes.
15. Remove the covers from the drain holes in the
9. If the injectors were not previously installed, refer to
Section 2.1.1 and install them at this time.
16. Install the exhaust manifold and connect the
10. Tighten the rocker arm bracket bolts to 50-55 lb-ft
17. Install the thermostat housing and the thermostat.
There is a possibility of
18. Install the air cleaners.
damaging the exhaust valves if the
exhaust valve bridge is not resting on
19. Connect the fuel lines.
the ends of the exhaust valves when
tightening the rocker arm bracket bolts.
20. Fill the cooling system and check for leaks.
Therefore, note the position of the
exhaust valve bridge before, during and
21. With the throttle in the OFF position, crank the
after tightening the bolts.
engine over to be sure that all of the parts function
11. Align the fuel pipes and connect them to the
injectors and the fuel connectors. Use socket J 8932-01
22. Before starting the engine, perform an engine tune-
to tighten the connections to 12-15 lb-ft torque.
up as outlined in Section 14.
CAUTION: Do not bend the fuel pipes
23. Refer to Section 13.1 and start the engine. After
and do not exceed the specified torque.
starting the engine, check all fuel line connections to
Excessive tightening will twist or
ensure that no fuel oil leaks into the cylinder head
fracture the flared ends of the fuel pipes
compartment to dilute the lubricating oil.
and result in leaks.
diluted by fuel oil can cause serious
24. After the engine has been warmed up (to at least
1600F.), recheck the torque on the cylinder head bolts.
12. Set the injector control tube assembly in place on
25. Recheck the exhaust valve clearance and the
the cylinder head and tighten the bolts, finger tight only.
injector timing after the engine reaches normal
When positioning the injector control tube, be sure that
the ball end of each injector rack control lever engages
the slot in the corresponding injector control rack. With
26. Examine all fuel oil, lubricating oil and water
one end of the control tube return spring hooked around
connections for possible leaks. Tighten the connec-
tions, if necessary.
27. Install the valve rocker cover, using a new gasket.
1970 General Motors Corp
SEC 1.2 Page 7