Piston Ring: Service and Repair

END GAP





1. Using a piston, push a new ring into the cylinder bore 15 - 20 mm (0.6 - 0.8 inch) from the bottom.

2. Measure the piston ring end-gap with a feeler gauge:
- If the gap is too small, check to see if you have the proper rings for your engine.
- If the gap is too large, recheck the cylinder bore diameter against the wear limits, See Cylinder Block Assembly / Service and Repair / Inspection and Service. If the bore is over the service limit, the cylinder block must be rebored.

Piston Ring End-Gap:
Top Ring
B16A2 engine
Standard (New): 0.20 - 0.35 mm (0.008 - 0.014 inch)
Service Limit: 0.60 mm (0.024 inch)
D16Y5, D16Y7, D16Y8 engines
Standard (New): 0.15 - 0.30 mm (0.006 - 0.012 inch)
Service Limit: 0.60 mm (0.024 inch)

Second Ring
B16A2 engine
Standard (New): 0.40 - 0.55 mm (0.016 - 0.022 inch)
Service Limit: 0.70 mm (0.028 inch)
D16Y5, D16Y7, D16Y8 engines
Standard (New): 0.30 - 0.45 mm (0.012 - 0.018 inch)
Service Limit: 0.70 mm (0.028 inch)

Oil Ring
B16A2 engine
Standard (New): 0.20 - 0.50 mm (0.008 - 0.020 inch)
Service Limit: 0.70 mm (0.028 inch)
D16Y5, D16Y7, D16Y8 engines
Standard (New): 0.20 - 0.70 mm (0.008 - 0.028 inch)
Service Limit: 0.80 mm (0.031 inch)

REPLACEMENT





1. Using a ring expander, remove the old piston rings.

2. Clean all ring grooves thoroughly.

NOTE:
- Use a squared-off broken ring or ring groove cleaner with blade to fit piston grooves.
- Top ring groove is 1.0 mm (0.039 inch) wide.
- Second ring groove is 1.2 mm (0.047 inch) wide.
- Oil ring groove is 2.8 mm (0.11 inch) wide.
- File down the blade if necessary.

CAUTION: Do not use a wire brush to clean ring lands, or cut ring lands deeper with cleaning tool.

NOTE: If the piston is to be separated from the connecting rod, do not install new rings yet.

3. Install new rings in the proper sequence and position.

NOTE: Do not reuse old piston rings.

RING TO GROOVE CLEARANCE





After installing a new set of rings, measure ring-to-groove clearances:

Top Ring Clearance
Standard (New):
B16A2 engine: 0.045-0.070 mm (0.0018-0.0028 inch)
D16Y5,D16Y7,D16Y8 engines: 0.035-0.060 mm (0.0014-0.0024 inch)
Service Limit: 0.13 mm (0.005 inch)

Second Ring Clearance
Standard (New):
B16A2 engine: 0.040-0.065 mm (0.0016-0.0026 inch)
D16Y5,D16Y7,D16Y8 engines: 0.030-0.055 mm (0.0012-0.0022 inch)
Service Limit: 0.13 mm (0.005 inch)

ALIGNMENT








1. Install the rings as shown.

NOTE: The manufacturing marks must be facing upward.

2. Rotate the rings in their grooves to make sure they do not bind.





3. Position the ring end gaps as shown: