Piston Rings - Yaroslavl Engine Plant YMZ-536 Operation Manual

1 – piston; 2 – top compression ring; 3 – 2
4 – oil control ring; 5 – circlips; 6 – piston pin; 7 – connecting rod

PISTON RINGS

The split-type piston rings are made of special cast iron and
installed into the corresponding piston grooves.
The piston ring set is as follows:
 the first (top) compression ring is configured as double-
sided trapezoid ring with a chamfer on the inner diameter at the top
end. The barrel-shaped working surface of the ring has a chrome-
diamond coating;
 the second compression ring with a rectangular cross
section has a chamfer on the inner diameter at the bottom end. The
ring has a "minute-angle" working surface.
 the third oil control ring is boxy type, with a helical
expander and chrome layer protection on its scraping edges.
The compression rings have a «Top» mark on the top end.
60
Fig. 13. Piston:
nd
compression ring;