Rotor Swap Question

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Cmiertschin
Posts: 47
Joined: Dec 23, 2022

by 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.
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Burgerbob
Posts: 6327
Joined: Apr 23, 2018

by 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.
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Matt_K
Posts: 4809
Joined: Mar 21, 2018

by 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
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JohnL
Posts: 2529
Joined: Mar 23, 2018

by 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).
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MrHCinDE
Posts: 1039
Joined: Jul 01, 2018

by 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.
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Cmiertschin
Posts: 47
Joined: Dec 23, 2022

by Cmiertschin »

Thanks for the thoughts everyone, I'll probably look for a donor horn or valve section.
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harrisonreed
Posts: 6479
Joined: Aug 17, 2018

by harrisonreed »

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JohnL
Posts: 2529
Joined: Mar 23, 2018

by JohnL »

[quote="Cmiertschin"]My horn has the two vertical ports...[/quote]
So the OP's 3BF has the original valve layout, like this:
<ATTACHMENT filename="3bf.jpeg" index="1">[attachment=1]3bf.jpeg</ATTACHMENT>
as opposed to the new valve design, like this:
<ATTACHMENT filename="3bf-new.jpeg" index="0">[attachment=0]3bf-new.jpeg</ATTACHMENT>
so a using the new style valve wouldn't be just a drop-in.
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harrisonreed
Posts: 6479
Joined: Aug 17, 2018

by harrisonreed »

What's the bore size on the 36H valve? Would that work?
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IdoMeshulam
Posts: 88
Joined: Aug 20, 2019

by 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.