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

Valve Seat









Intake valve seat ring hole diameter
0.3 (0.012) O.S. 36.30 - 36.325 mm (1.429 - 1.430 inch)
0.6 (0.024) O.S. 36.60 - 36.625 mm (1.441 - 1.442 inch)

Exhaust valve seat ring hole diameter
0.3 (0.012) O.S. 33.30 - 33.325 mm (1.311 - 1.312 inch)
0.6 (0.024) O.S. 33.60 - 33.625 mm (1.323 - 1.324 inch)

Valve seat contact width
Intake 0.9 - 1.3 mm (0.035 - 0.051 inch)
Exhaust 0.9 - 1.3 mm (0.035 - 0.051 inch)
Service oversize 0.30, 0.60

Seat angle
Intake 45°
Exhaust 45°