Pontiac firebird 1968 - Cylinder Head and Valves-Recondition

SIX CYLINDER ENGINE
6-17
equal distance from head. Do not use sealer of any
kind on threads*
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 in-
stallations procedure using new gaskets and seals as
required.
7 5 3 1 2 4 6
CYLINDER HEAD AND VALVES-RECONDITION
RECONDITION
The condition of the cylinder head and valve me-
chanism significantly determines power, perform-
ance and economy of a valve-in-head engine. Ex-
treme 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 ad-
justment.
DISASSEMBLE
1. Remove cylinder head and gasket as previously
described. Place cylinder head on two blocks of
wood to prevent damage.
2. Using tool J 8062, compress the valve springs
and 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.
Fig. 6-27 Cylinder Head Bolt Tightening Sequence
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 ex-
haust ports, combustion chambers, or external
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
.a/
Fig. 6-26 Cylinder Head Locating Dowel Pins
Fig. 6-28 Cleaning Valve Guide Bore