Vanguard BIG BLOCK M540000, Repair Manual, Page: 102 / 168

8. Obtain the Piston Ring Expander (see SECTION 3 -
TROUBLESHOOTING - Special Tool List) .
NOTE: Always use the piston ring expander to prevent
excessive ring twist and expansion. Over expansion may
cause the ring to crack opposite the ring gap. Damaged or
distorted rings result in blow-by of exhaust gases, increased
oil consumption, and lower service life of valves and other
components.
9. Carefully install the oil wiper ring (
A , Figure 126) into the
middle ring groove, so that the two painted marks are to
the right of the ring end gap.
NOTE: Installing the oil wiper ring upside down will cause
oil to be scraped up into the combustion chamber resulting
in excessive oil consumption and lower service life on valves
and other components.
10. Carefully install the compression ring (
B ) into the top ring
groove, so that the single painted mark is to the right of
the ring end gap.
11. Rotate piston rings using the palms of both hands. Verify
that the rings rotate freely without sticking.
12. Stagger the ring gaps around the piston. Proceed as
follows:
A. Rotate expander spring, so that the gap is positioned
at the front of the piston ( A , Figure 127).
127
B. Rotate bottom oil rail to position the gap 90° from the
gap in the expander spring ( B ).
C. Rotate top oil rail to position the gap 180° from the
gap in the bottom oil rail ( C ).
D. Rotate the middle oil wiper ring to align the gap with
the gap in the expander spring ( D ).
E. Rotate the top oil compression ring to position the
gap 180° from the gap in the oil wiper ring ( E ).
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