Cylinder Head And Valves; Intake Valve Guide Seal Installation; Cylinder Head Locating Dowel Pins - Pontiac Grand Prix Service Manual

6-16 1969 PONTIAC SERVICE MANUAL
Fig. 6-25 Intake Valve Guide Seal Installation
1. After applying sealer, place a new cylinder head
gasket in position over dowel pins in cylinder block
(Fig. 6-26).
-
2. Carefully guide cylinder head into place over dowel
pins and gasket.
3. Start all bolts in threads.
NOTE: Bolts are of two different lengths. When inserted
in proper holes. all bolts will project an equal distance
Jiom head. Do not use sealer of any kind on threadr.
4. Tighten cylinder head a little at a time with a torque
wrench. Tighten center bolts and then end bolts (Fig.
6-27). The final torque should be 95 lb. ft.
Reverse steps 1-7 of Removal to complete installations
procedure using new gaskets and seals as required.
CYLINDER HEAD AND VALVES
RECONDITION
The condition of the cylinder head and valve mecha-
nism significantly determines power, performance and
economy of a valve-in-head engine. Extreme care
should be exercised when conditioning the cylinder
head and valves to maintain correct valve stem-to-
-guide clearance, correctly ground valves, valve seats of
correct width and correct valve adjustment.
DISASSEMBLE
1. Remove cylinder head and gasket as previously
described. Place cylinder head on two blocks of wood
to prevnet damage.
remove valve keys. Remove spring caps, spring seats,
oil seals, and springs.
3. Remove valves from bottom of cylinder head and
place them in a rack in their proper sequence so they
can be assembled in their original positions.
CLEAN AND INSPECT
1. Clean all carbon from combustion chambers and
valve ports.
2. Thoroughly clean the valve guides using tool J 8101
(Fig. 6-28).
3. Clean all carbon and sludge from rocker arms.
4. Clean valve stems and heads on'a buffing wheel.
5. Clean carbon deposits from head gasket mating
surfaces.
6. Wash all parts in cleaning solvent and dry them
thoroughly.
7. Inspect the cylinder head for cracks in the exhaust
ports, combustion chambers, or exumal cracks to the
water chamber.
8. Inspect the valves for burned heads, cracked faces or
damaged stems.
9. Check fit of valve stems in their respective bores.
NOTE: Excessive valve stem to bore clearance will
cause lack of power, rough idling and noisy valves, and
may cause valve breakage. Insufficient clearance will
result in noisy and sticky functioning of the valve and
disturb engine smoothness of operation. Intake valve
stem-to-bore clearance should be
.0016"
to .0033" while
exhaust stem'clearance should be .0021" to .0038". By
using a micrometer and suitable telescope hole
check the diameter of valve stem in three places; top,
center and bottom. Insert telescope hole gauge in valve
guide bore, 'measuring at center. Subtract highest
reading of valve stem diameter from valve guide bore
center diameter to obtain valve to valve guide clearance.
2. Using tool J 8062, compress the valve springs and
.
Fig. 6-26 Cylinder Head Locating Dowel Pins