Piston Ring, Engine

Piston Rings
End gap
Compression
(top, in gauge) 0.17-0.33 mm (0.0067-0.0130 inch)
(bottom, in gauge) 0.3-0.55 mm (0.0118-0.0217 inch)
Oil ring (steel rail, in gauge) 0.15-0.65 mm (0.006-0.026 inch)
Groove width
Compression (top and bottom) 1.54-1.52 mm (0.0606-0.0598 inch)
Oil 3.05-3.03 mm (0.1201-0.1193 inch)
Ring width
Compression (top and bottom) 1.460-1.490 mm (0.0575-0.0587 inch)
Oil ring Side seal, snug fit
Ring-to-groove clearance
1st ring 0.030-0.080 mm (0.0012-0.0032 inch)
2nd ring 0.030-0.080 mm (0.0012-0.0032 inch)