Pontiac FIREBIRD 1972 Service Manual page 600

6-88 1972 PONTIAC SERVICE MANUAL
3. From beneath engine, pull connecting rod, with bear-
ing shell in place, into position against crankpin.
4. Remove rubber hoses. Install bearing cap and cap
nuts and tighten to 43 lb. ft. (all except 307 engine)
or 45 lb. ft. (307 engine).
5. Replace oil pump and oil baffle, if they were
removed.
6. Install cylinder head and intake manifold.
CONNECTING ROD AND PISTON
ASSEMBLY
CAUTION: Use care at all times when handling
and servicing connecting rods and pistons. To
prevent possible damage to these units, do not
clamp rod or piston in vise since they may
become distorted. Do not allowpistons to strike
against one another, against hard objects or
bench surfaces, since distortion of piston con-
tour or nicks in soft aluminum material may
result.
DISASSEMBLE
1. Remove piston rings, using proper piston ring
remover. It is important that rings be removed care-
fully to prevent scratching or burring of ring grooves
and lands).
2. Using a suitable arbor press, place the spring and
plunger into the bore of the base support and position
on an arbor press with the pilot plunger indexed in
the bottom of piston pin bore. See insert in Fig. 6-154
for correct base support and pilot plunger for the type
pistons being serviced.
3. Using the pilot plunger (or plate) indicated in Fig.
6-1 5 1 the pin may be pressed out far enough to index
with the bore in the base.
4. Remove pilot plunger and spring from base.
5. Complete removal of pin using pin driver J 6901-3
(all except 307 engine) or J 9510-2 (307 engine) and
base alone.
1
--
- .
PISTON
J 9510 3
i -
8
1
REMOVAL TOOL
Fig. 6-154 Removing Piston Pin
grooves, and oil slots in oil ring groove, using suitable
cleaning tools and solvent.
2. Clean piston pin, rod, cap, bolts and nuts in suitable
solvent. Reinstall cap on connecting rod to insure
against subsequent mixing of caps and connecting
rods.
3. Carefully examine piston for rough or scored bearing
surfaces; cracks in skirt or head; cracked, broken, or
worn ring lands; scored, galled, or worn piston
bosses. Damaged or faulty pistons should be re-
placed.
If piston pin bosses are rough or worn out-oflround
and the piston is otherwise serviceable, the pin bosses
may be honed for oversize pins. Before fitting over-
size pins, however, it is advisable to check fit ofpiston
in bore.
4. Inspect piston pin for scoring, roughness, or uneven
wear.
5. Inspect bearing shells to see that they are serviceable.
Fit of bearings should be checked when engine is
being assembled.
CYLINDER BORES,
INSPECT
6. Remove bearing cap and bearings.
CLEAN AND INSPECT
1. Clean carbon, varnish, and gum from piston surfaces,
including underside of piston head. Clean ring
Inspect 'cylinder bores for out-of-round or excessive taper
with an accurate cylinder gauge (J 8087 or comparable) at
top, middle and bottom of bore. Measure cylinder bore
parallel and at right angles to the centerline of engine to
determine out-of-round. Variation in measure from top to
bottom of cylinder indicates taper in cylinder.