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


Ring Groove Clearance 0.020 - 0.070 mm

Standard End Gap
No.1 0.25 - 0.35 mm
No.2 0.35 - 0.50 mm
Oil Ring (side rail) 0.15 - 0.40 mm

Minimum End Gap
No.1 1.05 mm
No.2 1.20 mm
Oil Ring (side rail) 1.05 mm