Harmonic Balancer; Valve Seat And Face Angle; Lower Front Timing Cover Retaining Bolts - Pontiac Grand Prix Service Manual

6-18
1969
PONTIAC SERVICE MANUAL
A-SEAT WID1 H
8-FACE ANGLE
C-SEAT ANGLE
D-VALVE FACE
D
A
Fig. 6-30 Valve Seat and Face Angle
run hotter as its thickness is diminished; therefore, i f
valve face cannot be cleaned up without grinding to
point where outside diameter of valve has a sharp edge,
the valve should be replaced. Whenever it is necessary to
replace a valve, the new valve should be of same stem
diameter as valve removed (unless the valve guide is
reamed to provide proper
fit).
Width of exhaust valve seats should be 1/16" to
3/32". Intake valve seats should be 1/32" to 1/16"
wide. If seat width is excessive, it should be narrowed
by grinding with a flat stone. This is the only method
that should be used to narrow seat.
2. Check concentricity of valve seat and valve guide.
Concentricity of valve seat and valve guide can be
checked by using a suitable dial indicator or prussian
blue. When using dial indicator, total runout should
not exceed .002".
When prussian blue is used, a light coat should be
applied to face of valve only and valve rotated in its
seat. If blue appears all the way around valve seat,
valve seat and valve guide are concentric with one
another.
3. Check concentricity of valve stem and face of valve.
After cleaning prussian blue from valve and seat,
lightly coat valve seat with prussian blue again and
rotate valve in guide. If blue appears all the way
around valve, valve stem and valve face are concentric
with one another.
NOTE: Both tests in steps 2 and 3 are necessary to
insure proper valve seating.
IMPORTANT: If it is necessary to grind any pit from
rocker arm end of valve stem, feed end squarely against
grinding wheel. Only the extreme end of the valve stem is
hardened to resist wear. Do not grind end excessively.
ASSEMBLE
1. Starting with No. 1 cylinder place exhaust valve in
the port and place valve spring and cap in position.
Place spring and cap on exhaust valves. Then using J
8062 spring compressor, compress spring and install oil
seal with J 22330 and valve keys. See that seal is flat
and not twisted in the valve stem groove and that keys
seat properly in valve stem groove.
NOTE: Place valve springs in position with closed coil
end toward cylinder head.
2. Assemble remaining valves, valve springs, shields,
spring caps, oil seals and valve locks in cylinder head.
Check seals by placing vacuum cup of J 22330 over
stem and cap, squeeze vacuum cup to make sure no oil
leaks past oil seal.
3. Install cylinder head as previously described.
HARMONIC BALANCER
REMOVE
4
I. Loosen generator at adjusting bracket and pivot bolt
'
and remove fan belt from harmonic balancer. On cars
equipped with power steering, also remove power
steering pump belt from harmonic balancer.
2. Position fan so wide angles will be at top and
bottom, allowing access to balancer.
3. Remove harmonic balancer attaching bolt and
retainer washer.
4. Remove harmonic balancer using puller J 6978. Use
of a washer (manifold bolt washer) in end of shaft will
prevent tool damaging threads in crankshaft.
Fig. 6-31 Lower Front Timing Cover Retaining Bolts