Piston Ring: Testing and Inspection
INSPECTIONPISTON AND PISTON RINGS
1. Clean the piston.
1) Using a gasket scraper, remove the carbon from the piston top.
2) Using a groove cleaning tool or broken ring, clean the piston ring grooves.
3) Using solvent and a brush, thoroughly clean the piston.
NOTE: Do not use a wire brush.
2. The standard measurement of the piston outside diameter is taken 39.15mm(1.5413in) from top land of the piston.
3. Calculate the difference between the cylinder bore inner diameter and the piston outer diameter.
Piston-to-cylinder clearance: 0.02 -- 0.04mm (0.0008 - 0.0016in)
4. Inspect the piston ring side clearance.
Using a feeler gauge, measure the clearance between new piston ring and the wall of ring groove.
If the clearance is greater than maximum, replace the piston.
5. Inspect the 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 rings. If the gap is too large, recheck the cylinder bore inner diameter. If the bore is over the service limit, the cylinder block must be rebored.
PISTON PINS
1. Measure the outer diameter of piston pin
2. Measure the piston pin-to-piston clearance.
Piston pin-to-piston clearance: 0.011 - 0.018mm (0.0004 - 0.0007in)
3. Check the difference between the piston pin outer diameter and the connecting rod small end inner diameter.
Piston pin-to-connecting rod interference: -0.033 - -0.016mm (-0.0013 - -0.0006in)