1.6 Piston and Piston Rings
DETROIT DIESEL 53
Fig. 10. - Measuring Piston Ring Side Clearance
Fig. 9. - Measuring Piston Ring Gap
NOTE: The oil control ring expander
illustrated in Fig. 10. Refer to Section 1.0 for the
must be completely seated in the oil
specified ring clearances and allowable wear limits.
ring groove.
The ends of the
expander can very easily be
Install Compression Rings on Piston
overlapped. If this occurs, the oil
With the connecting rod assembly inspected and
control rings will protrude slightly
assembled to the piston as outlined in Section 1.6.1,
refer to Fig. I for the proper location of the piston rings
and be broken when the piston ring
on the piston.
compressor is installed over the
piston and rod assembly, or when
IMPORTANT : Lubricate the piston rings
the piston and rod assembly is
and piston with engine oil before
installed in the cylinder liner.
assembling.
2. Install the top oil ring with the gap 180 from the ends
Assemble the compression rings on the piston with tool
of the expander.
J 8128, as shown in Fig. 2, and stagger the ring gaps
around the piston. When installing the compression or
3. Check the ends of the expander to be sure they are
oil control rings, do not spread the rings more than is
not overlapped.
necessary to slip them on the piston to avoid
overstressing the rings.
4. Install the bottom oil ring with the gap 45 from the
gap of the top oil ring. Recheck to be sure the ends of
Install Oil Control Rings on Piston
the expander are not overlapped.
Install the oil control rings by hand, with the scraping
NOTE: Do not, at any time, cut off or
edge of each ring down, as follows:
grind the ends of the oil ring
expander to prevent the ends from
1. Install an expander in the upper oil ring groove (Fig.
overlapping. Cutting off or grinding
1), being careful not to overlap the ends.
the ends of the expander will
decrease the tension on the oil
control rings and result in high
lubricating oil consumption.
5. Install the second set of oil control rings and
expander in the same manner as described above.
1972 General Motors Corp.
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