Polished Valves

[HKS]

Can anyone tell me with which material are the valves polished or coated to reduce the intake temperature?

[Carlos]

Was your question thermal & wear coating technology for intake and exhaust valves?

Yes I have information on file.

[mep]

Just this week I heard from a engineer who is working in a big
engine company, that he once walked around the factory and wondered why the valve seat rings are covered with copper.
He asked several other engineers but nobody could give him a propper answer.

[Tom]

The copper will be used because copper is a very soft metal and the valves are coming back into their seat very hard and very fast. The copper, being ductile, will absorb the energy very well and prevent damage to the valve which would result in stress cracking.

I'm not sure exactly what advantage it gives but according to wikipedia

"Copper has a high electrical and thermal conductivity, second only to silver among pure metals at room temperature."

[HKS]

Just this week I heard from a engineer who is working in a big
engine company, that he once walked around the factory and wondered why the valve seat rings are covered with copper.
He asked several other engineers but nobody could give him a propper answer.

Valves are mainly quoted so that the valves don't take up much of the heat for the combustion chamber thus keeping the inlet n A/F mixture cooler and in case of exhaust valves lesser heat energy is lost.

But I still don't know which material is used to coat valves

[Carlos]

Here is several links on valve coating and an article on piston coating
http://www.casidiam.com/appn_4.htm
http://www.swaintech.com/store.asp?pid=10539
http://www.aa1car.com/library/2005/eb80544.htm