The maker of the valves suggests using a bronze based seat, what are the best bronze based material to use?
What about copper based materials for valve seats?

The make of the valve either delwest or manley probably says for you to use a copper/bronze based seat.  That is just because the matierial is softer and won't wear the titanium as fast.  I know many people who have used a "soft" standard seat and have had much sucess with it.  Instead of the valve wearing out the seat the seat will wear out the valve. Been running ti valves on soft stock seat for over a year now on my bmw engine.

If you can gundrill do that, I bought some material for valve guides it took 2 drills to bore 32 guides, next time Ill rather buy a gundrill, btw here are the guides:




For the seats, I first tried to do the drilling on a manual machine, and then just bore out with a boring bar on the cnc, however after a short while, the manual drill was blunt as well, so I got out our gundrill, and did the whole operation in the cnc, the gundrill worked really well here, I have not yet taken pics of these.

Not sure, if you want long life, go with silicone bronze guides, the material is cheap as well...
Manganese have better performance with acceptable wear, the material is also cheap, we will be doing a run 30 or so sets of Manganese guides soon.
Beryllium/copper is very expensive, if you wont be running titanium valves, don't bother. Same with trojan, it is very expensive, the material cost alone is about as much as you would pay for a set of manganese guides, but look at it as a replacement for beryllium/copper with better properties, no toxic elements, and slightly cheaper. Drilling it is tricky but a carbide drill will solve that, but it machines really nice, the above pictures doesn't really do it justice. These are better:

If beryllium-copper is too expensive, then I would investigate one of the high alloy bronzes like Ampco 45 or the Trojan alloy.  Reasonable high temperature strength, good thermal conductivity, and low wear against Ti are the obvious goals.  Good luck.

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