beryllium copper valve seats for street.
and not take heat as well. You ought to make them 'splain
how the seat dropping has to do with the seat insert material
rather than geometry or the head letting go of it. Changing
material when it's not a materials problem is not a solution,
only an expense.
Like already mentioned, beryllium copper is used for high end race engines with titanium valves, and one of the reasons it's used is because it is soft. Rather than having the expensive and often custom titanium valves wear out, the seats wear out instead. It's much cheaper to machine a valvejob rather than replace the valves.
Using beryllium copper in a daily driver is silly. Steel alloys are more commonly used for a reason. I can't think of a single reason why beryllium copper should be used rather than a steel or powdered metal alloy.





