WÄRTSILÄ VASA 6L32, Instruction Manual

Page: 188 / 394

5 Measure the height of the piston ring grooves, e.g. with
an inside micrometer.
6 Inspect anti-polishing ring. Turn ring upside down after
first period. Change the ring every second period.
When mounting a new cylinder liner, or honing the old liner, all
rings are to be replaced by new ones, acc. to chapter 04.
7 Check the gudgeon pin and big end bearing clear-
ances by measuring the pin diameters and assembled bear-
ing bores separately. When measuring the big end bearing bore
all the connecting rod screws (upper and lower) must be tight-
ened to the stated pressure.
a) Big end bearings of trimetal type can be used until the overlay
is worn through. When the underlaying nickel barrier of the lining
material is exposed the bearing must be replaced.
b) Wear of bimetal bearing shells can be settled by measuring
thickness. For this purpose a ball anvil micrometer should be
used.
For bimetal-type bearing, the wear limits given in chapter 06.2
must be applied.
When replacing a big end bearing both the upper and the lower
bearing shell must be renewed.
Only bearings of same type to be used as a pair.
Mark new bearings with the bearing number.
Note! It is very important that the bearing shells are mounted straight.
11.3.5 Assembling and mounting of piston and
connecting rod
1 Lubricate the gudgeon pin, and mount it from the same
side from where it was removed, with the end marked with the
drawing number in the same direction. The cylinder number
is stamped on the piston crown and connecting rod, Fig 11-3.
When changing the piston, mark the new piston with the same
cylinder number in the same place as on the replaced one.
At low temperatures, the gudgeon pin may stick but will be
easily fitted after heating the piston to about 30°C, e.g. in oil.
2 Mount the securing ring (7).
11 Crank Mechanism: Crankshaft, Connecting Rod, Piston 32-200020
11 - 10 WÄRTSILÄ 32