Supah vs ordinary piston valve

[shockwave]

I'm just wandering if there is a difference in performance between a supah (chamber seal?) and barrel sealing piston valve. Couse as far as I understand from the supah valve photos at spudtech there is not much difference. I have built a gun based on the one GalFisk built with a few minor changes. Here is a diagram of my latest piston driven gun:



Now, according to my calculations the cross section area of the barrel is smaller then the one of the opening between the barrel and chamber so that means the flow is not limited by that opening. The supah valve design would look something like this:



Will that give more power to my gun? I myself doubt that, becouse the flow gets limited by the barel anyway. Correct me if I'm wrong.

[)DEMON(]

seems perfectly all right to me

[shockwave]

Thing is I hear ppl say that supay is alot better then a piston valve so I'm just wandering why apart from supa being a hell alot bigger then the piston valve I guilt 8)

[benzy2]

I would make it like the bottom one if you have the choice. It seems like the bottom one would have a better flow out of the barrel. In the top example the air has a lot less room in between the piston and the barrel when open which may not be much difference in reality though. The flow would seem to be restricted by the outter chamber also in the top model. The air has to take a 90* right turn and then once to the edge of the barrel make a 180* turn. This cant be good on flow not to mention that it is restricetd to the area in between the barrel and the chamber which looks small(it may not be a problem depending on the area of the barrel vs the area of the chamber). The bottom design just takes a 90* bend out of the barrel which will cause less resistance and would flow better giving better performance. Again Im not using any formulas on this and the actual difference may be so small you can notice it but it could be very big. If you have the option make it like the bottom one. If you already made it like the top one then dont worry about it and try to make the next one more like the bottom one.

[Jakal444]

Supah Valves are well lubricated and machinined to a very high quality, this is the reason why they are better, but whats the difference if you ask me? I'm guessing that the piston you designed will only be a couple of FPS less than the Supah but I could be wrong.

[boilingleadbath]

Would you mind trying to explain why good machining makes a bit of difference?
And like it's hard to lubricate things...

Anyway, there will be some flow resistance going around the bend, so I'd go with the second one.
(which really isn't like the supah... which is a chamber sealing valve.)