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: Specifications

Piston Ring
Ring closed gap
Top ring
Standard 0.20 - 0.35 mm (0.0079 - 0.0138 inch)
Limit 1.0 mm (0.039 inch)
Second ring
Standard 0.37 - 0.52 mm (0.0144 - 0.0203 inch)
Limit 1.0 mm (0.039 inch)
Oil Ring
Standard 0.20 - 0.50 mm (0.0079 - 0.0197 inch)
Limit 1.5 mm (0.059 inch)
Ring groove gap
Top ring
Standard 0.040 - 0.080 mm (0.0016 - 0.0031 inch)
Limit 0.15 mm (0.0059 inch)
Second ring
Standard 0.030 - 0.070 mm (0.0012 - 0.0028 inch)
Limit 0.15 mm (0.0059 inch)