Piston Ring, Engine

Piston Rings
Ring end gap
Compression
(top, gauge diameter) 0.15-0.25 mm (0.0059-0.0098 in)
(bottom, gauge diameter) 0.30-0.55 mm (0.0118-0.0216 in)
Oil ring (steel rail, gauge diameter) 0.15-0.45 mm (0.0059-0.0177 in)
Ring groove width
Compression
(top) 1.230-1.25 mm (0.0484-0.0492 in)
(bottom) 1.530-1.55 mm (0.0602-0.0610 in)
Oil ring 2.53-2.55 mm (0.0996-0.1003 in)
Ring width
Upper comp ring 1.17-1.19 mm (0.0460-0.0468 in)
Lower comp ring 1.47-1.49 mm (0.0578-0.0586 in)
Ring-to-groove clearance (upper and lower compression rings) 0.040-0.080 mm (0.0015-0.0031 in)