4-25
ENG
CYLINDER AND PISTON
EBS00250
CHECKING THE PISTON RINGS
1. Measure:
•
piston ring side clearance
Out of specification
Replace the piston
and piston rings as a set.
TIP
Before measuring the piston ring side clear-
ance, eliminate any carbon deposits from the
piston ring grooves and piston rings.
2. Install:
•
piston ring
(into the cylinder)
TIP
Level the piston ring into the cylinder with the
piston crown.
3. Measure:
•
piston ring end gap
Out of specification
Replace the piston
ring.
TIP
The oil ring expander spacer’s end gap cannot
be measured. If the oil ring rail’s gap is exces-
sive, replace all three piston rings.
Piston ring side clearance
Top ring
0.015 ~ 0.055 mm
(0.0006 ~ 0.0022 in)
<Limit>: 0.09 mm (0.0035 in)
2nd ring
0.015 ~ 0.055 mm
(0.0006 ~ 0.0022 in)
<Limit>: 0.09 mm (0.0035 in)
Piston ring end gap
Top ring
0.150~0.300 mm
(0.0059~0.0118 in)
<Limit>: 0.500 mm (0.0197 in)
2nd ring
0.300~0.450 mm
(0.0118~0.0177 in)
<Limit>: 0.650 mm (0.0256 in)
Oil ring
0.200 ~ 0.700 mm
(0.0079 ~ 0.0276 in)
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