Air Gun Forums - Mrod .25 high power valve mod

Note: This mods are OK on Gen1 .25 valve. I would not recommend them on the Gen2 valve. There is less material behind the poppet. For gen 2 valve I would not go past .187 for the exit port.

Throat: .256

Here is the view of the exit port. Mods. tube and breech opening increased to .325. exit port .203
I also made the hammer track longer by just over ⅛ in

https://farm9.staticflickr.com/8589/...7a1bcaf9e5.jpg

I don't know what else I can do to get more power out of the valve. other than removing some material from the valve body so I can gain a little more hammer travel.

I hope this helps and I'm open for any other suggestions. I have not tested this valve so I have no idea of the performance.

Gauge block: opend as much as possible
Hammer. Removed the adjuster screw for more travel. Casted lead in the side openings for 109gram hammer

[IMG]https://farm9.staticflickr.com/8571/...b8c15bd446.jpg[/IMG]

Angled exit port.
https://farm9.staticflickr.com/8648/...596b3940a6.jpg

Valve intake: center opening .325, side openings .184 I would not open the side openings more than .184. it is important to only do 3 opening in this configuration and placement. The reason is that if not you will drill through the breech screw opening and you will have a mayor air leak.

https://farm9.staticflickr.com/8599/...bb00f5512f.jpg

Inside of the valve bore out to ½ in

https://farm9.staticflickr.com/8561/...cb6f5ae8d8.jpg

Moving parts. PEEK poppet (From Doug - PakProtector), conical spring. and spring holder. I shorten the spring holder by about ¼in. On the valve body you can see the holes for this valve to fit Gen2 trigger

https://farm9.staticflickr.com/8597/...6a351328_b.jpg

For the transfer port I have two option. Both opened to .203
Top: 2 1mm orings and stainless standoff.
bottom. PTFE tubing cut to size.
I'm going to try the tubing first and see if it seals and there are no leaks.

https://farm9.staticflickr.com/8582/...5d2b4eb446.jpg