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 Ring Width
Top Compression 0.0577 - 0.0587 inch
Bottom Compression 0.0577 - 0.0587 inch
Piston Ring Side Clearance [1]
Top Compression 0.0013 - 0.0033 inch
Bottom Compression 0.002 - 0.004 inch
Oil Snug
Piston Ring Gap
Top Compression 0.010 - 0.020 inch
Bottom Compression 0.010 - 0.020 inch
Oil (Steel rail) 0.015 - 0.055 inch


[1] Allowable limit - 0.002 inch maximum increase in clearance.