Piston Ring: Testing and Inspection

PISTON RINGS AND RING GROOVES






Measure the piston ring side clearance. If the measured value exceeds the service limit, insert a new ring in a ring groove to measure the side clearance.
If the clearance still exceeds the service limit, replace the piston and rings together.
If it is less than the service limit, replace only the piston rings.
Specification;
Side clearance, first and second ring, 0.03 - 0.07 mm (0.0012 - 0.0028 inch)
Wear Limit, 0.1 mm (0.004 inch)

PISTON RING END GAP






To measure the piston ring end gap, insert a piston ring into the cylinder bore. Position the ring at right angles to the cylinder wall by gently pressing it down with a piston. Measure the gap with a feeler gauge. If the gap exceeds the service limit, replace the piston ring.
Standard Value;
No. 1, 0.25 - 0.45 mm (0.0098 - 0.0177 inch)
No. 2, 0.35 - 0.50 mm (0.0138 - 0.0197 inch)
Oil ring side rail, 0.20 - 0.70 mm (0.0079 - 0.0276 inch)
Wear Limit;
No. 1, 0.8 mm (0.031 inch)
No. 2, 0.8 mm (0.031 inch)
Oil ring side rail, 0.1 mm (0.004 inch)