GTA

All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: hpmr2400 on August 12, 2015, 01:18:11 PM

Title: Valve stems
Post by: hpmr2400 on August 12, 2015, 01:18:11 PM
Hey guys, I have been using a marauder poppet valve stem I'm my disco valve, made a brass bushing for it and all. And it does take a lot less hammer preload to get it open . Now I have been thinking about getting more brass tubing in the next size down which is 1/8 o.d x 7/64. I was thinking of making a valve stem from 7/64 drill rod . My question is , would going to 7/64 make the valve easier to open or would it be the same. I know that the marauder poppet opens easier because of harder material.
Title: Re: Valve stems
Post by: Motorhead on August 12, 2015, 02:15:19 PM
Hey guys, I have been using a marauder poppet valve stem I'm my disco valve, made a brass bushing for it and all. And it does take a lot less hammer preload to get it open . Now I have been thinking about getting more brass tubing in the next size down which is 1/8 o.d x 7/64. I was thinking of making a valve stem from 7/64 drill rod . My question is , would going to 7/64 make the valve easier to open or would it be the same. I know that the marauder poppet opens easier because of harder material.
So long as the head diameter of poppet remains the same .. in practical operation you won't see any difference in a stem diameter change ( Tho there is one happening tho ever so slight )

* What you are gaining is Throat area as ratio of throat I.D. / stem O.D. changes.
You now have the start of a valve that will flow better at reduced pressure such as a regulated set up, or a valve given an increase in transfer size and a tad more lift height capable of producing more power.

Honestly feel the 1/8" stem M-rod / P-rod poppet in a nice fit brass bearing sleeve is about ideal for that platform.

JMO ...
Scott
Title: Re: Valve stems
Post by: rsterne on August 12, 2015, 03:11:25 PM
AFAIK, the next size down in brass tubing is 3/32" ID, which is pretty small, I would be worried about bending the stem.... I agree that a 1/8" stem is about ideal for the Disco platform.... The opening force depends on the diameter of the head of the poppet, not the stem, and of course the pressure in the reservoir.... The stem diameter only changes the closing force, and hence the dwell....

Bob
Title: Re: Valve stems
Post by: hpmr2400 on August 12, 2015, 03:22:46 PM
Thanks Motörhead , just rolling ideas , I Wanted to be able to use even less preload and hammer weight . Right now I'm using a 2240 spring cut in half with 28gram hammer with atroke adjuster turned out 8 turns And getting 690s with 850psi of air. Still need to lighten the hammer more. I think that's the key with this low pressure
Title: Re: Valve stems
Post by: Motorhead on August 12, 2015, 03:28:30 PM
850 psi ??? ... is this some sort of regulated set up your working with ?
Title: Re: Valve stems
Post by: hpmr2400 on August 12, 2015, 03:49:16 PM
Yes ninja tank regulated at 850 psi. With tank attached to paintball remote hose, nice and light weight like this
Title: Re: Valve stems
Post by: hpmr2400 on August 12, 2015, 03:57:05 PM
I would like to see if I can get 15.9 up to 840-50 fps might take a lot more work and probably not ideal pressure for efficiency , but we'll see
Title: Re: Valve stems
Post by: Motorhead on August 12, 2015, 03:58:44 PM
Yes ninja tank regulated at 850 psi. With tank attached to paintball remote hose, nice and light weight like this
In that case ... Lighten the OEM hammer a bunch