Pistons, Piston Rings And Piston Pins - Mitsubishi S3L Service Manual

CYLINDER BLOCK, CRANKSHAFT,
PISTONS AND OIL PAN
Figure 94 Measuring diameter of piston
Item
Diameter of piston
Maximum permissible difference between average weight of all pistons in
one engine, g (oz)
No. 1 compression ring clearance
Figure 95 Measuring clearance between piston ring
and groove
72 / 195 72 / 195
Direction transverse
to piston pin
Standard
0.25
(0.009 8)
oversize
0.50
(0.019 7)
oversize
No. 2 compression
ring clearance
19.1 Pistons, Piston Rings and
Piston Pins
1. Diameter of piston
Measure the diameter of the piston at its skirt in a
direction transverse to the piston pin with a micrometer
as shown in the illustration. If the diameter exceeds the
limit, replace the piston. Select a new piston so that the
difference between average weight of all pistons in one
engine does not exceed the standard.
Norminal size
78.00 77.93 to 77.95
(3.070 9) (3.068 1 to 3.068)
78.25 78.18 to 78.20 (3.077
(3.080 7) 9 to 3.078 7)
78.43 to
78.50 87.45
(3.090 5) (3.087 8 to
3.088 6)
5 (0.18)
2. Clearance between piston ring and groove
1) Measure the clearance between the groove
and piston with a straight edge and a feeler
gauge as shown in the illustration. If the
clearance exceeds the limit, replace the ring.
Item
No. 1
compression ring
No. 2
compression ring
Oil ring
2) If the clearance still exceeds the limit after
new piston rings have been installed, replace
the piston.
ENGLISH
INSPECTION
Standard
77.80
(3.063 0)
78.05
(3.072 8)
78.30
(3.082 7)
__
Standard
0.06 to 0.10
(0.002 4 to 0.003 9)
0.06 to 0.10
(0.002 0 to 0.003 5)
0.06 to 0.10
(0.001 2 to 0.002 8)
Service Manual Mitsubishi SL-Series diesel engines
Unit: mm (in.)
Limit
.Unit: mm (in.)
Limit
0.30
(0.011 8)
0.20
(0.007 9)
0.20
(0.007 9)
Version 08/2004