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 Gap & Groove Clearance

Ring Gap:
Ring Gap-Top Compression Ring 0.20-0.36 mm (0.008-0.014 in.)
Ring Gap-2nd Compression Ring (Micro-Napier) 0.20-0.40 mm (0.0078-0.0157 in.)
Ring Gap-Oil Control (Steel Rails) 0.25-0.76 mm (0.010-0.030 in.)

Side Clearance:
Top and Second Compression Ring 0.04-0.08 mm (0.0016-0.0031 in.)
Oil Ring (Steel Rails 0.038-0.184 mm (0.0015-0.0073 in.)