to be on the ring travel area. Check
create side clearance with new piston
ring gap with a feeler gauge. The
rings greater than .008 inch; if piston pin
specified ring end gaps, using
bore does not exceed 2.003 inch; and if
standard cylinder sleeves of 5.251
no cracks or scores are detected in piston
inch-5.252 inch bore are:
pin bosses, on the skirt, or in the
top compression ring .021 inch-
may be reused with a reasonable life
.039 inch, 2nd and 3rd rings .023
expectancy of one-half to three-fourths
inch-.041 inch and oil control ring
that of new pistons.
(w/spring) .013 inch-.031 inch.
(4) Fitting pistons to cylinder sleeves.
The top compression ring and the oil
cylinder sleeves, and running clearances
control ring should never be filed to
between the pistons and the cylinder
open the gap because the chrome
sleeves, should be taken at room
plating might be loosened by the file
temperature (70 ).
and later distributed through the
engine, causing damage or scoring
Pistons must be fitted to their
of the piston and the cylinder sleeve.
respective cylinder sleeves before
(b) Measure ring-to-groove clearance
the piston rings are installed to
(top of ring to top of groove in
provide a running clearance of not
The specified ring to
less than .007 inch.
groove clearances, using a new
clearance will result in premature
piston and new rings, are:
failure of pistons and/or cylinder
top compression ring .004 inch-
.006 inch, 2nd and 3rd rings .003
inch-.005 inch, oil control ring
measure the I.D. of the cylinder
(w/spring) .0015 inch-.0035 inch.
(6) Piston ring Installation. After piston rings
have been properly fitted, lubricate piston
measure the O.D. of the piston skirt
and rings with Series 3 engine oil. Install
at a right angle to the piston pin and
rings on piston (with side marked "Top" or
at the bottom of the skirt. For a true
"T" toward top of piston), using a piston
reading, the O.D. of the piston skirt
ring remover and installer tool.
can only be measured in the area
between the very bottom of the skirt
When installing rings on pistons, do
and .560 inch from the bottom.
not spread the rings more than
(c) The difference between the two
necessary. Whenever a connecting
readings is the running clearance.
rod with the piston is secured in a
vise, be extremely careful that the
(5) Fitting piston rings to pistons.
bottom of the piston skirt is not
(a) The gap between ends of piston
nicked. Use lead protective jaws to
rings should be measured before
protect the bottom of the skirt from
rings are installed on pistons.
nicks and also to prevent nicks in the
Insufficient end gap will cause
rod which will lead to piston and/ or
scored rings, scored cylinder
sleeves, and other damage. Check
connecting rod failure.
the ring gap by inserting each ring
(a) Install the oil control ring by
into the cylinder sleeve in which it is
removing the coil spring from the
to be used. Use a piston to push
ring and lubricate spring with clean
ring squarely down in the bore of
engine oil. Install spring in
the cylinder sleeve and far enough