Piston Ring, Engine

PISTON RING SIDE CLEARANCE





^ Measure the side clearance of piston ring and piston ring groove with feeler gauge.
Standard:
Top ring: 0.045 - 0.080 mm (0.0018 - 0.0031 inch)
2nd ring: 0.030 - 0.070 mm (0.0012 - 0.0028 inch)
Oil ring: 0.065 - 0.135 mm (0.0026 - 0.0053 inch)
Limit:
Top ring: 0.11 mm (0.0043 inch)
2nd ring: 0.10 mm (0.0039 inch)
^ If the measured value exceeds the limit, replace piston ring, and measure again.
^ If it still exceeds the limit, replace piston.

PISTON RING END GAP





^ Check if the inner diameter of cylinder bore is within the specification. Refer to "Piston to Cylinder Bore Clearance".
^ Lubricate with new engine oil to piston and piston ring, and then insert piston ring until middle of cylinder with piston, and measure piston ring end gap with feeler gauge.
Standard:
Top ring: 0.22 - 0.32 mm (0.0087 - 0.0126 inch)
2nd ring: 0.22 - 0.32 mm (0.0087 - 0.0126 inch)
Oil ring: 0.20 - 0.60 mm (0.0079 - 0.0236 inch)
Limit:
Top ring: 0.56 mm (0.0220 inch)
2nd ring: 0.52 mm (0.0205 inch)
Oil ring: 0.96 mm (0.0378 inch)
^ If out of the limit, replace piston ring. If the gap still exceeds the limit even with a new ring, re-bore cylinder and use oversized piston and piston ring.