Section IV. CYLINDER HEAD AND VALVES

TM 10-3930-633-34

sequence to specifications. Install the crankcase

cylinder firing position and install the distributor. With

the distributor ignition points open position (No. 1 cyl-

ventilation regulator valve in the rocker arm cover.

inder) install the hold-down clamp and screw. Tighten

Attach the vent hose to the intake manifold inlet tube.

the screw snug, but not tight.

(34) Install the cylinder block drain plugs and oil

(38) Use a new gasket and install the fuel pump.

pressure sending unit. Install the oil level dipstick tube

Torque the bolts to specifications, Install the carbure-

and dipstick.

tor fuel inlet line and distributor vacuum line.

(35) Install the oil filter mounting adapter, Coat

(39) Install the distributor cap and spark plug

the seal surface of a new oil filter with grease (or en-

wires. Connect the spark plug wires. Connect the dis-

gine oil). Install the oil filter until the seal surface

tributor primary and secondary high tension wires to

contacts the cylinder block, then tighten the filter an

the ignition coil.

additional turn.

(40) Remove the engine from the work stand.

(36) Install the ignition coil and bracket.

Install the engine front support.

(37) Position No. 1 cylinder on TDC after the

compression stroke. Set the distributor points to No. 1

Section IV. CYLINDER HEAD AND VALVES

6-13. General

as the stud nut is tightened (6-7.2). When the push rod

to rocker arm clearance has been eliminated, tighten

head carries the valves,

The cylinder

the stud nut an additional 1 turn to place the hydraulic

individually-mounted valve rocker arms, manifold

lifter plunger in the desired operating range.

assembly, coolant outlet housing and thermostat.

Valve guides are cast integrally in the head. The valve

arrangement, from front-to-rear, is exhaust-intake for

each cylinder.

6-13.1. Valve Clearance Adjustment

Valve clearance should be set to zero lash at each

1000 hours of operation, or whenever rough engine

idle or noisy lifters indicate the need for this

procedure.

a. Install an auxiliary starter switch, Crank the

engine with the ignition switch OFF.

b. Make 2 chalk marks on the crankshaft damper

(fig. 6-7. 1). Space the marks approximately 120

degrees apart so that, with the timing mark, the

damper is divided into three equal parts (120 degrees

is 1/3 of the distance around the damper

circumference).

c. Rotate the crankshaft until No. 1 piston is on

TDC at the end of the compression stroke. Check the

breakaway torque (torque required to turn nut in a

counterclockwise direction) of each stud nut. Replace

the stud nut if the breakaway torque does not meet

Figure 6-7.1. Timing Marks on Crankshaft Damper.

specifications. If, after replacing the stud nut, the

breakaway torque still is not within specifications,

e. Repeat this procedure for the remaining set of

replace the stud.

valves, turning the crankshaft with an auxiliary starter

switch, 1/3 turn at a time, in the direction of rotation,

d. With No. 1 piston on TDC at the end of the

while adjusting the valves in the firing order sequence,

compression stroke, adjust the intake and exhaust

1-5-3-6-2-4. This procedure requires 2 complete turns

valve clearance for No. 1 cylinder. Loosen the rocker

of the crankshaft.

arm stud nut until there is end clearance in the push

f. Operate the engine and check for rough engine

rod, then tighten the nut to just remove all the push

idle or a noisy lifter(s). Valve clearance set too tight

rod to rocker arm clearance. This may be determined

will cause rough idle and valve clearance set too loose

by rotating and/or moving the push rod with the fingers

Change 1

6-13