Piston Ring

END GAP [1]
Nominal
Top 0.100-0.250 mm (0.0039-0.0098 inch)
Second 0.27-0.42 mm (0.0106-0.0165 inch)
Oil 0.15-0.65 mm (0.0059-0.0255 inch)
Service Limit (Maximum)
Top 0.50 mm Max (0.0196 inch)
Second 0.65 mm Max (0.0255 inch)
Oil 0.90 mm Max (0.0354 inch)

SIDE CLEARANCE
Nominal
Top 0.040-0.075 mm (0.0015-0.0029 inch)
Second 0.040-0.085 mm (0.0015-0.0033 inch)
Oil Snug fit
Service Limit (Maximum) 0.10 mm (0.0039 inch)

[1] Specification 82.4 mm diameter gauge.