Doosan DE12TIS - Page 70

ENGINE DISASSEMBLY - 63 -
3.2.9. Piston rings
1) Visual check
Replace the piston rings with new ones if detected worn or broken when the engine is overhauled.
2) Piston ring gap
 Insert the piston ring into the upper portion
of the cylinder liner bore so that it is held at
a right angle to the cylinder liner wall.
 Measure the piston ring gap with a feeler gauge.
 Replace piston rings with new ones if the gap is beyond the limit.
3) Piston ring side clearance
 Fit the compression ring and oil ring in the
piston ring groove.
 With a feeler gauge, measure side clearance
of each ring, and replace either the ring or
piston if the measured value is beyond the
specified limit.
4) Piston ring tension
 With a tension tester, measure piston ring tension.
 Replace the piston ring if the measured value is beyond the limit.
Standard Limit
Top ring 0.30 ~ 0.45 mm 1.5 mm
2nd ring 1.0 ~ 1.2 mm 2.0 mm
Oil
ring
DE12/T/TI 0.30 ~ 0.50 mm
1.5 mm
DE12TIS 0.40 ~ 0.70 mm
EA0M4032
Feeler
gauge
Standard Limit
Top ring -
2nd ring
0.07 ~ 0.102 mm 0.15 mm
2nd ring
0.05 ~ 0.085 mm 0.15 mm
Standard
Top ring 2.27 ~ 3.41 kg
2nd ring 2.0 ~ 3.0 kg
Oil ring 4.03 ~ 5.57 kg