Rotor Swap Question

[Cmiertschin]

Hey all, my 3BF's valve casing has been messed up at some point in prior ownership, and my tech has recommended replacement when possible. It's functionally usable right now, just a little janky. I'm considering swapping in an Instrument Innovations rotor (and probably messing with the wrap to account for different sizes of parts); other option of course is finding a donor bell section and swapping rotors out. My horn has the two vertical ports (late 60's and quite "well-loved"), so adjustments would need to be made with a new 3BF rotor anyway. Thoughts on the I.I. swap? Or other possible alternatives? This horn is quite well-used, only reason I'm considering going a little wild with it.

[Burgerbob]

I don't think Olsen makes a rotor in .530. The .562 large tenor rotor would be much, much too large for that application.

[Matt K]

I think the smallest after market valve I’ve seen in that size is Voight. Hagmann also sell a 530 but is obviously not even close to drop replacement

[JohnL]

Your best bet would be to find a donor horn. Obviously a 3BF valve would be the preferred option, but one from a small-bore Olds with an f-attachment might also work (they're .515" and have the same general port configuration as the early 3BF rotors).

[MrHCinDE]

You might have luck in finding one on here from someone who decides to convert their 3B/F to a straight 3B? Every so often that idea comes up. It‘s worth a WTB/ISO post in the classifieds at least.

[Cmiertschin]

Thanks for the thoughts everyone, I'll probably look for a donor horn or valve section.

[harrisonreed]

Screenshot_20230515-114843.png

[JohnL]

My horn has the two vertical ports...

So the OP's 3BF has the original valve layout, like this:

3bf.jpeg

as opposed to the new valve design, like this:

3bf-new.jpeg

so a using the new style valve wouldn't be just a drop-in.

[harrisonreed]

What's the bore size on the 36H valve? Would that work?

[IdoMeshulam]

I think I have what you need, bought it for a project but ended up not using it. Shoot me an email if you're interested.