Laminated Segment Rings - Perkins 4.108 Workshop Manual

PISTONS AND CONNECTING RODS-F.4
expanding tool of the type shown in Fig. F.3. These
rings, being made of cast iron are therefore com-
paratively brittle, so when fitting care should be taken
not to expand any ring more than is necessary to just
clear the piston.
SECOND
AND FOURTH SEGMENTS
FIRST AND THIRD SE.GMENTS
laminated Segment Rings
The procedure for fitting the laminated type is different,
in as much as the ring comprises four separate seg-
ments, these may be fitted by hand in the following
sequence with the piston crown uppermost:-
1. Fit the first segment to the piston so that when
held horizontally between the thumb and fingers
and radially compressed the ring ends point
downwards (see Fig. F.9).
F10
Place this ring on the bottom face of the fourth
ring groove with the gap over the gudgeon pin
bore.
PISTON CROWN
F9
2. Fit the second segment on top of the first, so that
when compressed as described above the ends
point upwards. Position the gap at 180
0
to that of
the first segment.
3. Fit the third segment as in (1) above with the gap
immediately above the gap of the first segment.
4. Fit the fourth segment as in (2) above with the
gap immediately above the gap of the second seg-
ment. If all the segments have been fitted correctly
then they will be positioned as shown above.