Pontiac FIREBIRD 1972 Service Manual page 603

V-8 ENGINE 6-9 1
Piston and pin must be at room temperature when check-
ing fit and pin must be able to fa// from piston by its own
weight.
FITTING OVERSIZE PINS IN PISTONS AND
CONNECTING ROD PIN BORES
In case the standard size piston pin does not fit properly
in the piston, an oversize piston pin must be fitted. Piston
pins are available in .001" and .003" oversize.
When oversize pins are used, the piston pin bosses must
be honed to give required fit. It will also be necessary to
hone the connecting rod pin bore to fit the oversize pin,
using a precision hone.
CAUTION: A special grit hone is used for hon-
ing the connecting rod pin bore. The piston pin
size should be. GW8" to ,0016" larger than con-
necting rod pin bore for proper press fit. The
piston pin should not show any movement un-
der 15lW 16. minimum load after assembly in
rod.
ASSEMBLE CONNECTING ROD TO PISTON
There is a notch cast in the top of all piston heads to
facilitate proper installation. The piston assemblies should
always be installed with notch toward front of engine (Fig.
6-161). Position rod in piston so that oil squirt hole is
toward camshaft.
PISTON PIN
REPLACE
1. Place pilot plunger and spring in the support base to
be used as a pilot end stop. See figure 6-162 insert for
correct base support and pilot plunger for type pis-
tons being serviced.
2. Place pilot plunger of tool J 6901 or J 9510 in piston
pin bore and place on arbor press.
3. Coat piston pin and rod lightly with graphite lubri-
cant.
4. Place tool J 6901-3 (all except 307 engine) or J 95 10-2
(307 engine) in piston pin and press pin into piston
and connecting rod (Fig. 6-162) until piston pin bot-
toms against plunger of tool J 6901 or J 9510. Piston
must turn freely on pin. If piston binds on pin, disas-
semble, hone piston pin bosses slightly and reassem-
ble.
FRONT O F ENGINE
*
UOTCH
Fig. 6-1 6 1 Piston and Rod Assembly
Fig. 6-162 Installing Piston Pin