Originally Posted by cosrep
Is it true that cossie YB exhaust valves are sodium filled and if so what advantage does this offer?
Whats the difference between standard valve guides and the bronze versions?
Hi,
Exhaust YB valves are sodium filled to help heat transfert between valve head and stem. Because sodium is a metal, and is liquid state when engine is running.
In same idea, bronze valve guide is better for stem slipping, and is better to transfer heat between stem valve and head case.
Regards.
Claude