Rotary Valve Question

[Paulver]

I have a 1970 Mirafone 186 rotary valve BBb which I love. When I bought it, the fourth valve had been damaged and repaired by a previous owner. It works okay, but the stem is rotating a bit off center. I think it was soldered off center.... not sure. Not a big problem, but being a bit anal about mechanics operating as designed, it's irritating to me. My question is...... are all four valves identical on this horn or are they each different? I've been told that they are all the same, and I've also been told that valves 1 & 3 are identical, and valves 2 & 4 are identical...... but different from 1 & 3.
I've contacted Miraphone, but I haven't heard back from them yet. I'd like to replace the valve and I have a source for one. I just don't know if it will be what I actually need. Don't want to buy the wrong thing and be stuck with it.

Anyone know for sure????

Thanks.

[Rick Denney]

1 and 2 are the same and 3 and 4 are the same, with the only differences being how the stop arm is oriented. But that doesn't mean they are interchangeable. Especially for one that old, they will have been hand-fitted.

But I understand that Miraphone will actually make you a valve to replace one that is damaged, though you'll probably need to send the damaged one to them.

I'm not understanding your issue. How does the valve turn at all if the stem is off-center? By the way, the stem of a rotary valve is not soldered in place--near as I can tell the whole valve including the stem is machined from a single block.

Rick "not getting the word picture" Denney

[bloke]

1 and 2 are the same and 3 and 4 are the same, with the only differences being how the stop arm is oriented. But that doesn't mean they are interchangeable. Especially for one that old, they will have been hand-fitted.

But I understand that Miraphone will actually make you a valve to replace one that is damaged, though you'll probably need to send the damaged one to them.

I'm not understanding your issue. How does the valve turn at all if the stem is off-center? By the way, the stem of a rotary valve is not soldered in place--near as I can tell the whole valve including the stem is machined from a single block.

Rick "not getting the word picture" Denney

' pretty sure they mean that the stem is bent - ABOVE where it exits the bearing.
Typically, I study which way they "swing" and (after "studying" two or three quarter-turns, I give 'em a few whacks until the center screw hole doesn't drift off-center.

(duh: Pre-whackification, I remove the action arm, as well as the center screw.)

[Paulver]

After looking at it a bit closer just now, I saw that the fourth valve linkage screw head is different than the other three screws. Much larger and thicker head, and it has two spacers (thicker than the washers on the other valve assemblies) between the head and the linkage. Putting a light on things, I see that the stem is definitely messed up. The flat side is pretty much non-existent. I also see some scrapings/shavings in the area where the linkage collar slides down over the shaft. That leads me to believe that it was forced together. The way it spins gives the illusion that it's bent..... and it could possibly still be, and at the very least, the collar that slides down over the shaft/stem is slightly off center. I don't want to mess with it for fear that something unexpected goes wrong, and I need this horn for next week through March.

The guy I bought it from several years ago, told me that he thought it had been broken and repaired by soldering things together after being bent, so that's where the soldering comment came from. I never looked closely at it because it worked pretty well. Still don't know for sure the extent of the damage. I don't want to take it apart until I know which type of valve I need for a repair. It also looks like I might need the collar that slides down over the shaft. Looks like it was a home repair.

For now it works, so I'm not gonna mess with it. All that said, I was all set to have the whole valve assembly repaired/replaced by Lee Stofer a few years ago, but I got sidetracked by illness and couldn't get there conveniently after that. As time passed, I had other necessary places for the money to go to. So............ !!!!!

After I hit the Mega Millions or the Powerball, I'm gonna have the horn totally overhauled and restored.

[arpthark]

After looking at it a bit closer just now, I saw that the fourth valve linkage screw head is different than the other three screws. Much larger and thicker head, and it has two spacers (thicker than the washers on the other valve assemblies) between the head and the linkage. Putting a light on things, I see that the stem is definitely messed up. The flat side is pretty much non-existent. I also see some scrapings/shavings in the area where the linkage collar slides down over the shaft. That leads me to believe that it was forced together. The way it spins gives the illusion that it's bent..... and it could possibly still be, and at the very least, the collar that slides down over the shaft/stem is slightly off center. I don't want to mess with it for fear that something unexpected goes wrong, and I need this horn for next week through March.

The guy I bought it from several years ago, told me that he thought it had been broken and repaired by soldering things together after being bent, so that's where the soldering comment came from. I never looked closely at it because it worked pretty well. Still don't know for sure the extent of the damage. I don't want to take it apart until I know which type of valve I need for a repair. It also looks like I might need the collar that slides down over the shaft. Looks like it was a home repair.

For now it works, so I'm not gonna mess with it. All that said, I was all set to have the whole valve assembly repaired/replaced by Lee Stofer a few years ago, but I got sidetracked by illness and couldn't get there conveniently after that. As time passed, I had other necessary places for the money to go to. So............ !!!!!

If you want to post pictures of the issue for us to drool over and dissect, shoot me an email at beanhillbrass@gmail.com and I'll host 'em and post 'em for ya.

Well, technically Imgur hosts 'em, but I'm pretty fast about getting them uploaded.