Piston Ring: Testing and Inspection

INSPECTION

CAUTION: Used piston rings should not be transferred from one piston to another, regardless of mileage or piston ring failure may occur.

^ Inspect the piston rings for abnormal wear or damage. Replace if necessary. Replace all rings that are scored, broken, chipped or cracked.

PISTON RING END GAP





1. Insert the piston ring into the cylinder by hand and use the piston to push the piston ring slightly beyond bottom of the piston ring travel area 115 mm (4.5 inches) from cylinder block deck face.
2. Use a feeler gauge to measure the ring opening clearance (end gap).
3. If gap is outside of specifications, use a different ring set.
Top Ring: 0.20-0.25 mm (0.008-0.010 inch).
Second Ring: 0.30-0.50 mm (0.012-0.020 inch).
Oil Ring Rail: 0.40-1.40 mm (0.016-0.055 inch).

PISTON RING-TO-GROOVE CLEARANCE





NOTE: If lower lands have high steps, piston should be replaced.

1. Check ring-side clearance of compression rings with Feeler Gauge D81L-4201-A or equivalent inserted between ring and its lower land. Gauge should slide freely around entire ring circumference without binding. Any wear that occurs will form a step at inner portion of lower land.
2. If clearance is greater than service limit, replace piston ring.
3. If clearance exceeds service limit, even with a new piston ring, replace piston.
Top Ring: 0.04-0.075 mm (0.0016-0.0030 inch).
Second Ring: 0.02-0.052 mm (0.0016-0.0033 inch).
Oil Ring: Snug Fit.
Maximum (Compression Ring): 0.10 mm (0.004 inch).