Piston Ring, Engine

Piston ring end gap - compression (top, gauge diameter) 0.100 - 0.250 mm (0.0039 - 0.0098 inch)
Piston ring end gap - compression (bottom, gauge diameter) 0.27 - 0.42 mm (0.0106 - 0.0165 inch)
Piston ring end gap - oil ring (steel rail, gauge diameter) 0.15 - 0.65 mm (0.0059 - 0.0255 inch)
Piston ring end gap - compression (top, service limit) 0.50 mm maximum (0.0196 inch)
Piston ring end gap - compression (bottom, service limit) 0.65 mm maximum (0.0255 inch)
Piston ring end gap - oil ring (steel rail, service limit) 0.90 mm maximum (0.0354 inch)
Piston ring groove width - compression (top) 1.230 - 1.245 mm (0.0484 - 0.0490 inch)
Piston ring groove width compression (bottom) 1.530 - 1.545 mm (0.0602 - 0.0608 inch)
Piston ring groove width oil ring 2.530 - 2.555 mm (0.0996 - 0.1005 inch)