Mitsubishi S3L User Manual

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Service Manual Mitsubishi SL-Series diesel engines
Version 08/2004
ENGLISH
CYLINDER BLOCK, CRANKSHAFT,
PISTONS AND OIL PAN
INSPECTION
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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.
Unit: mm (in.)
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.
.Unit: mm (in.)
2) If the clearance still exceeds the limit after
new piston rings have been installed, replace
the piston.
Figure 94 Measuring diameter of piston
Direction transverse
to piston pin
Item Norminal size Standard Limit
Diameter of piston
Standard
78.00
(3.070 9)
77.93 to 77.95
(3.068 1 to 3.068)
77.80
(3.063 0)
0.25
(0.009 8)
oversize
78.25
(3.080 7)
78.18 to 78.20 (3.077
9 to 3.078 7)
78.05
(3.072 8)
0.50
(0.019 7)
oversize
78.50
(3.090 5)
78.43 to
87.45
(3.087 8 to
3.088 6)
78.30
(3.082 7)
Maximum permissible difference between average weight of all pistons in
one engine, g (oz)
5 (0.18) __
Figure 95 Measuring clearance between piston ring
and groove
No. 1 compression ring clearance
No. 2 compression
ring clearance
Item Standard Limit
No. 1
compression ring
0.06 to 0.10
(0.002 4 to 0.003 9)
0.30
(0.011 8)
No. 2
compression ring
0.06 to 0.10
(0.002 0 to 0.003 5)
0.20
(0.007 9)
Oil ring 0.06 to 0.10
(0.001 2 to 0.002 8)
0.20
(0.007 9)

Mitsubishi S3L Specifications

General

Brand	Mitsubishi
Model	S3L
Category	Engine
Language	English