Piston Ring: Testing and Inspection

Piston Ring Clearance:

1. Check piston ring side clearance.
Top ring: 0.04 - 0.08 mm (0.0016 - 0.0031 in)

2nd ring: 0.03 - 0.07 mm (0.0012 - 0.0028 in)

Max. limit of side clearance: 0.1 mm (0.004 in)

2. If out of specification, replace piston and/or piston ring assembly.

Piston Ring End Gap:

3. Check piston ring end gap.
Top ring: 0.28 - 0.52 mm (0.0110 - 0.0205 in)

2nd ring: 0.45 - 0.69 mm (0.0177 - 0.0272 in)
(For rings punched with R or T.)

2nd ring: 0.55 - 0.70 mm (0.0217 - 0.0276 in)
(For rings punched with N.)

Oil ring: 0.20 - 0.69 mm (0.0079 - 0.0272 in)

Max. limit of ring gap: 0.5 mm (0.020 in)

4. If out of specification, replace piston ring. If gap still exceeds the limit even with a new ring, rebore cylinder and use oversized piston and piston rings.