Hello, I'm from Belgium, don't speak German, so it will be in Englisch.
I have an classic circuitracer, CB50, and I was looking for an adres who can make titanium valves for a 50cc cilinderhead. I asked price ad an special company in the USA and it would cost a little 3000$ for 16 valves (8 sets from in and out). That's +- 2000€ --> that would be around 250€ for 2 titanium valves without shipping costs. I just want 1 (or maybe 2) sets. I'm looking or there is interest before I buy for 3000$ valves. People who are interested can contact me, please in englisch or not to difficult german.
no I have no experiences at all, for me it should be all new also. The only benefit I see in it, is that they are lighter --> more rotation without harder springs. How more power you'll have, that is different from engine to engine I think. It's for engines with a short stroke en the most power at high rotations (with a fast camshaft)
the company said that it isn't very nessecary to mount other valve guides and seats, but it's better with others. here the link I don't know price for other seats.
bigger valves means that the new seats must be cut and this will become a very expensive order. I guess the total of this modified head will be at approx. EUR 400,-/450,---. Lot of money for me and I think an investment into more cc will be better.
Ok, thanks for information and good luck with your project!