ENGINE AND ENGINE REBUILDING 123
Check the connecting rod side clearance with a
feeler gauge. Use a small pry bar to carefully spread
the rods to specified clearance
the "Piston Removal" procedure. Coat the rod
bearings with clean oil.
3. Using the proper ring compressor, in
sert the piston assembly into the cylinder so
that the notch in the top of the piston faces
the front of the engine (this assumes that the
dimple(s) or other markings on the connect
ing rods are in correct relation to the piston
notch(s).
4. From beneath the engine, coat each
crank journal with clean oil. Pull the con
necting rod, with the bearing shell in place,
into position against the crank journal.
5. Remove the rubber hoses. Install the
bearing cap and cap nuts and torque to spec
ification.
NOTE:
When more than one rod and pis-
ton assembly is being installed, the con-
necting rod cap attaching nuts should only
be tightened enough to keep each rod in
position until all have been installed. This
will ease the installation of the remaining
piston assemblies.
6. Check the clearance between the sides
of the connecting rods and the crankshaft us
ing a feeler gauge. Spread the rods slightly
with a small prybar to insert the gauge. If
clearance is below the minimum tolerance,
the rod may be machined to provide ade
quate clearance. If clearance is excessive,
substitute an unworn rod, and recheck. If
clearance is still outside specifications, the
crankshaft must be welded and reground, or
replaced.
7. Replace the oil pump, if removed, and
the oil pan.
8. Install the cylinder head(s) and intake
manifold, as previously described.
Crankshaft Servicing
Crankshaft servicing literally makes or breaks
any engine; especially a high performance one
such as the Corvette.
The most critical maintenance operation is
the replacement of the crankshaft main bear-
ings. These bearings are of the precision in-
sert design and do not require adjustment
through shims. They are offered in under-
sizes of 0.001 in., 0.002 in., 0.009 in., 0.010
in., 0.020m., and 0.030in.
Despite the advent of these inserts and ac-
companying precision machine work, it does
happen that sizing mistakes are made and no
crankshaft should be installed in a block with-
out checking clearances. One of the simplest
means of doing so is to use Plastigage®. This
is a wax-like plastic material that is formed
into precision threads. It will compress evenly
between two surfaces, without damage, and
when measured, will indicate the actual
clearance.
It is easiest to check bearing clearance with
the engine removed from the car and the block
inverted. This ensures that the crank is rest-
ing against the upper bearing shells. If Plas-
tigage is to be used on an engine still in the
vehicle, it will be necessary to support the
crankshaft at both ends so that clearance be-
tween the crankshaft and the upper bearing
shells is eliminated.
REMOVAL
1. Drain the engine oil and remove the
engine from the car. Mount the engine on a
work stand in a suitable working area. Invert
the engine, so the oil pan is facing up.
2. Remove the engine front (timing) cover.
3. Remove the timing chain and gears.
4. Remove the oil pan.
5. Remove the oil pump.
6. Stamp the cylinder number on the
machined surfaces of the bolt bosses of the
connecting rods and caps for identification
when reinstalling. If the pistons are to be re
moved eventually from the connecting rod,
mark the cylinder number on the pistons with
silver paint or felt-tip pen for proper cylinder
identification and cap-to-rod location.
