Question to Tom Kaye

[Fantom]

Tom,

I was thinking that by doubling the volume of the chamber of the classic valve I would be able to half the operation pressure, but before I start making holes in my valve to add an extra volume chamber I would like to know if you have done it and if you achieved any improvement in noise reduction without ruining the consistency of the valve. I'm aware that I would have to deal with a softer spring also.

I add that I don't mind a slower recharge cycle as I shoot very slowly.

Thanks,

Fantom

[Muzikman]

I really doubt you would be able to double the size of the chamber unless you tried something like the old SP Magic Box, which didn't work as advertized back then, so I doubt it will work for you now.

Oh, and your math is off. Pressure vs volume is not 1:1

[mostpeople]

PV=nRT

:ninja:

[Fantom]

I really doubt you would be able to double the size of the chamber unless you tried something like the old SP Magic Box, which didn't work as advertized back then, so I doubt it will work for you now.

Oh, and your math is off. Pressure vs volume is not 1:1

PV = P'V'

[ThePixelGuru]

If it did anything good, they would have done it on all Automags.
They didn't do it on all 'mags.
It doesn't do anything good.

LP is a pile of male cow poo. :ninja:

[Fantom]

up

[MANN]

up

You dont need to up this question. If it needed to be bigger it would have been. Drill a hole, and try it for yourself. You will find it doesnt help.

[Tracker]

actually all youll be doing is hurting your efficency

the magic box lowered the efficiency by about 10%, as did the smart valve, but by RAISING the operating pressure, as some people have done by restricting some of the chamber, they were actually able to gain about a 10% increase over stock

Tracker

[Fantom]

Thanks guys.

My objective is to reduce noise without impacting consistency.

Efficiency or recharge time are not issues.

Also, to do this I have to approach it as research.....first I have to find out if it has been done and what were the results (nice if I can see the numbers). If it has not been done, then I will do it and find out quatitatively the extent of change.

So, if any of you can tell me if it has been done and if there was a reduction in dB please come forward.

Note: The other day at the field, I was at the chrony and one kid showed me his brand new super expensive marker and I was amazed how quiet it was. That got me thinking that if I could lower the pressure of at least one of my AGD markers down to 200 psi, it would probably be as quite as an old Autococker I have.

The mod doesn't seem difficult....just tap the chamber and connect it to a cylinder, equivalent in volume, adjust the pressure down to approx 200 psi, adjust/change/make a new spring and make measurements. Of all this, I think the spring is going to be the most difficult part of the project.

[ThePixelGuru]

I'm gonna bet your barrel has far more of an effect on your marker's sound than anything else.

[Fantom]

I'm gonna bet your barrel has far more of an effect on your marker's sound than anything else.

That is true.

[athomas]

The way the mag works, doubling the air chamber won't cut the operating pressure in half. The Inside diameter of the powertube and the stem of bolt would also need to be adjusted. You could reduce the force of the bolt spring to compensate, but then you slow down the return of the bolt, even if you could maintain forward bolt speed. The bolt acts like a restrictor. That necessitates a higher operating pressure to maintain any kind of efficiency. The higher the operating pressure, the better the efficiency gets. And of course, the lower the pressure gets, the worst the efficiency gets as a greater amount of the pressure is required just to keep the bolt forward to allow the air to escape.

[MANN]

If you are planning on increasing the air chamber you will want to tap the front of the valve (1/8npt). like this:

http://i70.photobucket.com/albums/i83/mannsports/IMG_2473.jpg

And iirc the volume did allow a lower operating pressure. It was not half, but somewhere around 400iirc. if you want this one pm me, and we can try to work something out

[Fantom]

If you are planning on increasing the air chamber you will want to tap the front of the valve (1/8npt). like this:

And iirc the volume did allow a lower operating pressure. It was not half, but somewhere around 400iirc. if you want this one pm me, and we can try to work something out

Exactly what I was thinking.

PM'd