GMC Workshop Service and Repair Manuals

Piston Ring: Specifications

Piston Ring End Gap

First Compression Ring

Production .......................................................................................................................................................  0.300 - 0.450 mm (0.012 - 0.018 inch)
Service .............................................................................................................................................................  0.450 - 0.675 mm (0.018 - 0.027 inch)

Second Compression Ring

Production .......................................................................................................................................................  0.450 - 0.650 mm (0.017 - 0.025 inch)
Service .............................................................................................................................................................  0.675 - 0.975 mm (0.026 - 0.039 inch)

Oil Control Ring

Production ...................................................................................................................................................  0.249 - 0.759 mm (0.0098 - 0.0299 inch)
Service .............................................................................................................................................................  0.373 - 1.138 mm (0.015 - 0.045 inch)

Piston Ring to Groove Clearance

First Compression Ring .....................................................................................................................................  0.031 - 0.074 mm (0.0012 - 0.0029 inch)
Second Compression Ring ................................................................................................................................  0.031 - 0.074 mm (0.0012 - 0.0029 inch)
Oil Control Ring ....................................................................................................................................................  0.051 - 0.203 mm (0.002 - 0.008 inch)