Chevrolet Corvette 1963 Repair & Tune-Up Manual page 127

bly. The chamfered comers of the bearing caps
should face toward the front of the left bank
and toward the rear of the right bank, and the
boss on the connecting rod should face to-
ward the front of the engine for die right bank
and to the rear of the engine on the left bank.
On various engines, the piston compression
rings are marked with a dimple, a letter "T,"
a letter "O," "GM" or the word "TOP" to
identify the side of the ring which must face
toward the top of the piston.
Piston Ring and Wrist Pin
REMOVAL AND INSPECTION
Some of the engines covered in this guide
utilize pistons with pressed-in wrist pins; these
must be removed by a special press designed
for this purpose. Other pistons have dieir wrist
pins secured by snap rings, which are easily
removed with snap ring pliers. Separate the
piston from the connecting rod.
A piston ring expander is necessary for re-
moving piston rings without damaging them;
any other method (screwdriver blades, pliers,
etc.) usually results in the rings being bent,
scratched or distorted, or the piston itself
being damaged. When the rings are re-
moved, clean the ring grooves using an ap-
propriate ring groove cleaning tool, using care
not to cut too deeply. Thoroughly clean all
carbon and varnish from the piston widi sol-
vent.
CAUTION: Do not use a wire brush or
caustic solvent (acids, etc.) on pistons.
Inspect the pistons for scuffing, scoring,
cracks, pitting, or excessive ring groove wear.
If these are evident, the piston must be re-
placed.
The piston should also be checked in rela-
tion to the cylinder diameter. Using a teles-
SNA
P
RING
Piston rings and wrist pin
ENGINE AND ENGINE REBUILDING
TOP COMPRESSION
RING.
SECOND COMPRESSION
RINQ
EXPANDER
SNAP RING
PISTON 6 ROD
Removing the piston rings with expander tool
Removing wrist pin clips
RING GROOVE
CLEANER
Clean the piston ring grooves with a suitable tool
Measure the piston with a micrometer
coping gauge and micrometer, or a dial gauge,
measure the cylinder bore diameter perpen-
dicular (90%) to the piston pin, 2Va in. below
the cylinder block deck (surface where the
block mates with the heads). Then, with the
119
RING EXPANDER
90°