Buick LeSabre 1965 Service Manual page 67

ENGINE 2-45
is less than .015", file the ends
of rings carefully with a smooth
file to obtain proper gap.
f. Assembly and Installation
of Piston and Connecting
Rod Assemblies
NOTE: Connecting rods may be
sprung out of alignment in ship-
ping or handling; therefore, they
must be checked before pistons
and pins are installed.
Check bend and twist on an ac-
curate rod aligning fixture using
Guide Pin J-6047-16 (from wrist
pin press) in place of wrist pin.
Press V-block firmly and evenly
against guide pin to prevent cock-
ing pin in eye of rod which may
be up to .002" larger diameter
than pin.
1. To assemble piston, pin, and
rod, first place Piston Pin Spacer
J-6047-21 and Piston Support
J-6047-18 in base plate of press.
Use the piston support with the
full radial face upward.
2. Place rod in piston, with oil
spurt notch on s a m e side as
valve depressions in piston dome,
lubricate piston pin and inside
diameter of pin holes with Lubri-
plate. Insert pin into piston boss,
pushing pin through to move rod
over against opposite pin boss.
3. Place small end of Drive Pin
J-6047-4 in hole in upper (pro-
truding) end of piston pin and
p o s i t i o n the assembly in the
press.
4. Make certain that all units are
in alignment, then apply pressure
and force pin through rod until
Guide Pin J-6047-18 stops down-
ward travel.
5. Release pressure and remove
piston and rod assembly from
press. Rotate piston on pin to
check on fit between piston and
pin.
6. Install oil ring expander in
third groove of each piston, plac-
ing ends in area above either end
of piston pin where groove is
not slotted. Install oil ring over
expander with gap on same side
as valve depressions in piston
head.
NOTE: To make certain expander
ring does not overlap on 425 cu.
in. engines a red and blue mark
will be visible on ring. See Fig-
ure 2-47.
NOTE: The rails and spacer of
the oil ring are lightly held to-
gether with an oil soluble cement.
If parts have separated they may
be installed as individual pieces.
7. Install compression rings in
first and second lands of each
piston. Top rings are assembled
with inner bevel toward top of
piston and second ring inner bevel
toward bottom of piston. See Fig-
ure 2-48.
All c o m p r e s s i o n rings are
marked either with a dimple, or
a letter "O", to identify the side
of the ring which must be as-
sembled "UP".
NOTE: On 425 cu. in. engines
install chrome compression in top
land of piston. Install plain ring
backed up with an expander in the
second land of piston.
8. Make sure that cylinder bores,
pistons, connecting rod bearings
and crankshaft journals are absol-
utely clean, then coat all bearing
surfaces with engine oil.
Expander
Chrome
Ring
Rail Rail
Spacer
9. Before installation of a piston
and rod assembly in its cylinder
bore, turn crankshaft to place the
crankpin straight down.
10. Remove cap, and with bearing
upper shell seated in connecting
rod, i n s t a l l the long Guide
J-5239-2 on bolt which is on same
side of rod as the oil spurt notch
in the bearing parting surface.
Install short Guide J-5239-1 on
the other connecting rod bolt.
These guides hold the upper bear-
ing shell in place and protect the
crankpin journal from damage
during installation of connecting
rod and piston assembly.
11. Make sure that gap in oil
rails are on same side as valve
depressions in piston head so that
gap will be on high side of cyl-
inder bore, turn compression
rings so that gaps are not in line,
then compress all rings with
w r a p - a r o u n d type ring com-
pressor.
12. Insert piston and rod assem-
bly into its cylinder bore with the
long guide pin placed above the
crankpin. Push the a s s e m b l y
down until the rod bearing seats
on crankpin. See Figure 2-43.
13. Select new connecting rod
bearing, if necessary, as de-
scribed in paragraph 2-18. Other-
wise, install cap with bearing
lower shell on rod and tighten bolt
nuts to 30-40 ft. lbs. torque.
14. Install all other piston and
rod a s s e m b l i e s in the same
manner.
OIL RING
IDENTIFICATION
MARK UP
XPANDER
RAIL
SPACER
Figure 2-47—425 Cu. In. Engine
Piston Rings
Figure 2-48—Compression and
O i l Rings