Chevrolet 1963 Corvette, Руководство по ремонту и настройке

Страница: 128 / 346

120 ENGINE AND ENGINE REBUILDING
A—AT RIGHT ANGLE TO
CENTERLINE OF ENGINE
B—PARALLEL TO
CENTERLINE
OF ENGINE
Cylinder bore measuring points
Correct cylinder bore honing pattern
micrometer, measure the piston perpendic-
ular to its wrist pin on the skirt. The differ-
ence between the two measurements is the
piston clearance. If the clearance is within
specifications or slightly below (after the cyl-
inders have been bored or honed), finish
honing is all that is necessary. If the clear-
ance is excessive, try to obtain a slightly larger
piston to bring clearance to within specifica-
tions. If this is not possible obtain the first
oversize piston and hone (or if necessary, bore)
the cylinder to size. Generally, if the cylin-
der bore is tapered .005 in. or more or is out-
of-round .003 in. or more, it is advisable to
rebore for the smallest possible oversize pis-
ton and rings. After measuring, mark pistons
with a felt-tip pen for reference and for as-
sembly.
NOTE: Cylinder block boring should be
performed by a reputable machine shop
with the proper equipment. In some cases,
"clean-up" honing can be done with the
cylinder block in the car, but most exces-
sive honing and all cylinder boring must be
done with the block stripped and removed
from the car.
CHECKING RING END GAP
Piston ring end gap should be checked while
the rings are removed from the pistons. In-
correct end gap indicates that the wrong size
rings are being used;
ring breakage could oc-
cur.
Compress the piston rings to be used in a
cylinder, one at a time, into that cylinder.
Squirt clean oil into the cylinder, so that the
rings and the top 2 inches of cylinder wall are
coated. Using an inverted piston, press the
rings approximately 1 in. below the deck of
the block (on diesels, measure ring gap clear-
ance with the ring positioned at the
bottom
of ring travel in the bore). Measure the ring
end gap with a feeler gauge, and compare to
the "Ring Gap" chart in this chapter. Care-
fully pull the ring out of the cylinder and file
the ends squarely with a fine file to obtain the
proper clearance.
Measure piston ring end gap with feeler gauge
INSTALLATION AND SIDE CLEARANCE
MEASUREMENT
Check the pistons to see that the ring grooves
and oil return holes have been properly
-CENTERLINE OF ENGINE-
Measure cylinder bore with dial gauge
CROSS
HATCH
PATTERN
X