Piston Vs. QEV

[pizlo]

I';m fairly sure that a piston will deliver better performance, but would a 3/4 QEV or a piston housed in 3/4 material perform better.
If the piston was one inch would it be noticeably better than a 3/4 QEV?
Thanks.

[Ragnarok]

I'm fairly sure that a piston will deliver better performance, but would a 3/4 QEV or a piston housed in 3/4 material perform better.

Bit confused as to what you mean there.

If the piston was one inch would it be noticeably better than a 3/4 QEV?

Vastly. It should have twice the flow.

[pizlo]

I'm fairly sure that a piston will deliver better performance, but would a 3/4 QEV or a piston housed in 3/4 material perform better.

Bit confused as to what you mean there.

Would a 3/4 inch piston valve outperform a 3/4 inch QEV valve?
Also is a 3/4 inch QEV overkill for shooting BBs?

[VH_man]

3/8th QEV's are perfect for a .40 cal dartgun, so id say a 1/2 inch QEV is the smallest youd want to go.

plus, when it comes to performance, is overkill a bad thing?

[ALIHISGREAT]

plus, when it comes to performance, is overkill a bad thing?

there is only so much air you can get into a barrel so a 40m piston valve won't have any performance advantages over a 1/2" when the barrel is a bb barrel

[Ragnarok]

Would a 3/4 inch piston valve outperform a 3/4 inch QEV valve?
Also is a 3/4 inch QEV overkill for shooting BBs?

1) Depends quite a lot. Because piston valves are entirely custom, they could be better or worse. The piston valve on my HEAL is no larger than a 3/4" QEV, and opens just as fast, but it has the very significant added advantage of about 50% more flow and less dead volume.

2) Yes. You don't need more than a 3/8" valve for that really. A bit larger may help a bit, but beyond that, the barrel can only support so much flow, so you're wasting cash on larger valves.

[psycix]

Well there is one thing:

Say you got two valves:
Both open in "X" time.
Valve A has "Y" flow and valve B has 2Y flow.

The barrel can handle Y flow.
Say we would attach valve B on the barrel.
When the valve is only at 0,5X time, it is already half open thus it gives Y flow already!
This means that valve B wich opens in the same X time outperforms valve A!
They might have got the same opening TIME, but they have not the same opening SPEED, wich is basically Y per X.

The MAXIMUM flow may be overkill, but the opening speed, thats what its all about!

[pizlo]

I see, thanks for the information, it will all be in be in consideration when i keep thinking of my design.
@Rag, do you have a topic about HEALS piston, or a diagram?