Piston Ring

Check for side clearance.
If the limit is exceeded, replace the ring or piston, or both.
1. Standard value:
  1. NO.1: 0.03 - 0.07 mm (0.0012 - 0.0028 inch)
  2. NO.2: 0.02 - 0.06 mm (0.0008 - 0.0024 inch)
2. Limit:
  1. NO.1: 0.1 mm (0.0039 inch)
  2. NO.2: 0.1 mm (0.0039 inch)
Fig 1: Checking Piston Ring Side Clearance
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Install the piston ring into the cylinder bore. Force the ring down with a piston, the piston crown being in contact with the ring, to correctly position it at right angles to the cylinder wall. Then, measure the end gap with a feeler gauge.
If the end gap is excessive, replace the piston ring.
1. Standard value:
  1. NO.1 ring: 0.20 - 0.30 mm (0.0079 - 0.0118 inch)
  2. NO.2 ring: 0.35 - 0.50 mm (0.0128 - 0.0197 inch)
  3. Oil ring: 0.10 - 0.40 mm (0.0039 - 0.0157 inch)
2. Limit:
  1. NO.1, No.2 ring: 0.8 mm (0.031 inch)
  2. Oil ring: 1.0 mm (0.039 inch)
Fig 2: Checking Piston Ring End Gap
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.