Anyone modded a QEV for flow before?

[MrCrowley]

Has anyone thought about removing the "supports" from inside the barrel port of a McMaster QEV before? If you don't know what i'm talking about, look at this picture.

My guess is that the QEV may work at low pressures (under 300PSI), but much above that it might have problems sealing and may even get damaged. I think it would increase flow a fair amount but I don't want to risk it since I can't get another QEV that size under about $60USD here.

[POLAND_SPUD]

3/4" fastenal/european QEVs have no supports at all so I guess that you can do it... though you might have to use a different piston

[jackssmirkingrevenge]

I'm guessing it's just there to spread the load on the piston/diaphragm, so you might have wear issues or even failure at higher pressures. Still, does it have significantly less area than your barrel section?

[MrCrowley]

I'm guessing it's just there to spread the load on the piston/diaphragm, so you might have wear issues or even failure at higher pressures. Still, does it have significantly less area than your barrel section?

Yup, that's what I thought too. Now i'm thinking I could reinforce the piston at the back. The reason I wanted to do this was to see what the performance would be like if I chucked a golfball barrel on
I would say about 1/4 to 1/3 of the port is blocked by the supports. I could always remove the 4 "diagonal" supports and leave the two "vertical" ones.

[jackssmirkingrevenge]

I could always remove the 4 "diagonal" supports and leave the two "vertical" ones.

...and drill a hole through the central part

[MrCrowley]

OMGLOLZNOWAYZ...good point!
If only I had a chrony, soon everyone could be modding their QEV's

[Lentamentalisk]

I would suggest starting with just removing 3 of them, and grinding down the center piece to match. Also, you could shorten/streamline the down stream part considerably to help with flow. Also keep in mind, its not just about how much surface area is covered. It is directing the flow through smaller gaps, causing more turbulence and friction with the sides.

Btw, I am glad my nice crisp photographs can be of assistance.

[Crna Legija]

what if you glue a washer to the piston that way it would be stronger and less likely to brake

[Technician1002]

Adding mass to the pistion will slow it down.

I generaly use a larger valve when I need more flow.

[jackssmirkingrevenge]

I generaly use a larger valve when I need more flow.

Je , just buy a bigger QEV you tight kiwi front bottom

[MrCrowley]

I was going to build a 1" porting full metal valve but then I thought it was going to end up fairly costly and take a few weeks to build. I'll get around to it another day.

As for now, i've modden the supports so that only the two verticle ones remain and the middle piece. I've removed all the supports on the pilot side (same thing but at the "IN" port, no idea why they are there). So far, 260PSI and no leaking.

edit:
Lentamentalisk, yeah I noticed it was your picture. Please don't sue me

[deathbyDWV]

You shall be sued!!!

This is a good idea. I gives me an excuse to make a new qev launcher... Kinda...

[Brian the brain]

soon everyone could be modding their QEV's

I might have to try modding a QEV one day...

None of my valves have those restrictions though...
I have an unrestricted 2" porting factory made piston valve...with full flow..

[POLAND_SPUD]

Sue him! sue him! sue him! teach that aussie a lesson

i second BTB suggestion... you might as well mod an in-line valve

[psycix]

If it looks tough enough to survive without supports, take those mofo's out!