Piston Ring, Engine

Piston Ring End Gap:
Top Ring 0.006 - 0.011 inch (0.15 - 0.30 mm)
Second Ring 0.012 - 0.018 inch (0.30 - 0.45 mm)
Oil Rail 0.008 - 0.027 inch (0.20 - 0.70 mm)
Maximum 0.039 inch (1.0 mm)