Piston Ring, Engine

Piston Ring Compression:
Top Groove Side Clearance Keystone Type Ring
Second Groove Side Clearance 0.039-0.079 mm (0.0015-0.0052 inch)
Top Ring Gap 0.26-0.51 mm (0.010-0.020 inch)
Second Ring Gap 0.75-1.00 mm (0.030-0.039 inch)

Piston Ring Oil:
Groove Clearance 0.040-0.090 mm (0.0016-0.0035 inch)
Gap 0.25-0.51 mm (0.010-0.020 inch)