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

Piston ring Side clearance Compression (top) 0.040-0.075 Millimeter (mm)
Compression (bottom) 0.040-0.085 Millimeter (mm)
Oil ring Snug fit
Service limit 0.10 Millimeter (mm)
ring gap Compression (top) gauge diameter 0.100-0.250 Millimeter (mm)
Compression (bottom) gauge diameter 0.27-0.42 Millimeter (mm)
Oil ring (steel rail)
Specification 82.4 mm (3.2441 inch) diameter gauge
gauge diameter 0.15-0.6 Millimeter (mm)
Compression (top) service limit max. 0.50 Millimeter (mm)
Compression (bottom) service limit max 0.65 Millimeter (mm)
Oil ring (steel rail) service limit max 0.90 Millimeter (mm)