Beryllium copper is used for valve seats. It is only 2% beryllium, all that is needed, I guess.

When titanium valves are mentioned, I think of Del West Engineering. They have a very good reputation. Their titanium valves are one piece forgings. They can do hollow stems and even sodium filled stems. They have a European branch at Roche, Switzerland.


R.

Why titanium? It's strong as steel at half the weight. Titanium has a higher melting point than steel.
(The SR-71 spy plane had a titanium skin because neither stainless steel nor aluminum would retain their strength or not melt at very high speeds. This was reported about as soon as the planes were declassified.)