Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Piston Ring, Engine

Piston Rings
Piston Ring End Gap -
First Compression Ring - Measured in Cylinder Bore -
Production 0.23-0.44 mm (0.009-0.017 inch)
Service 0.23-0.5 mm (0.009-0.0196 inch)
Piston Ring End Gap -
Second Compression Ring - Measured in Cylinder Bore -
Production 0.44-0.7 mm (0.017-0.027 inch)
Service 0.44-0.76 mm (0.0173-0.03 inch)
Piston Ring End Gap - Oil Control Ring - Measured in Cylinder Bore -
Production 0.18-0.75 mm (0.007-0.029 inch)
Service 0.18-0.81 mm (0.007-0.032 inch)
Piston Ring to Groove Clearance - First Compression Ring -
Production 0.04-0.086 mm (0.00157-0.0033 inch)
Service 0.04-0.068 mm (0.00157-0.0033 inch)
Piston Ring to Groove Clearance - Second Compression Ring -
Production 0.05-0.088 mm (0.002-0.0034 inch)
Service 0.05-0.088 mm (0.002-0.0034 inch)
Piston Ring to Groove Clearance - Oil Control Ring -
Production -0.008 to +0.0176 mm (-0.0003 to +0.0069 inch)
Service -0.008 to +0.0176 mm (-0.0003 to +0.0069 inch)