UPDATED VALVE MOD
To get the valve apart put it in a vice. Use a small pipe wrench or channel locks on the cap. Does not need to look pretty on the outside. Like most things in the world it's what's inside that counts.
*Click on any image to enlarge*
Parts that help a great deal are.
1- Increase the volume.
Pic of the front of the valve cap. I have cut some of the threads off but left more than half for strength.
Use a 25/64" drill bit to remove about 1/4" from the inside, then polished inside.
2- Change port angle.
The port size in the valve was the same as the breech seal I decide to use.
The intake port may be drilled also but with the increased volume it should not
make much of a difference for the .22 guns. Larger caibers can benefit from a
larger intake especially if they are tube bulked.
Use a dremel to change the port angle. Then polished it up with a thin strip
of 600 grit sandpaper taped to a the back end of a small drill bit or similar
item, installed on the dremel. This is polished the area I just dremelled out.
Also polish the other area marked on the diagram. If I had messed this one up,
bottom arrow, my valve would leak constantly. I could have left it alone without losing
much at all but the more polished everything is the smoother the flow. As you can see
this port is not perfect. The angled area could be brought all the way up to the top edge
of the port and polished better for optimum performance, but you get the idea.
3- Lighter spring.
Here are some lighter springs. The spring should be about 1/8 to 1/4" longer
because I increased the volume on the valve by drilling into the valve cap.
The spring will actually close the valve even if it is very light but gas can
be wasted. I used one that's about half as strong. Too light a spring can cause
damage to the main tube as the hammer pin strikes it, at the front of the slot.
It can also cause the piercing pin to stick in the powerlet if the gun is not
bulked. I've also used two springs, slid together sideways to get the strength
I wanted. (see pic)
Pic contains dremel tools used, stock valve and a junk valve body used when
drilling the tube for safety screws.
4- Cut off piercing pin.
The above pictures also show before and after pics of the stem with and without
piercing pin. The metal is hard and the best way I have found to cut it is with
the dremmel and a thin cut off disc. CAUTION I cut a little at a time and let it
cool in between or drip water on it to prevent a melted seal. The stem can be
shaped but I've found that it's easy to mess the seal up because the stem gets
hot when you are working on it.
Then chuck what's left in a drill and use a file or sandpaper
as in step two. Round the sharp edges and polish the rest. I
took my time because too much pressure on the brass will
make it spin on the shaft making it hard to shape.
SAFETY MOD
Drill a couple of holes through the tube even
with the exhaust port. I put my set screws on
the sides of the tube which I tapped out to
match the screws. Remove the burrs from
inside the tube, install the valve, mark it,
and drill slightly into it. (to reduce the
number of burrs, install an old valve body
in the tube before you drill it.)
You can see the set screw just above the safety. Now your face will not
wear the valve when you pull the trigger on you beefed up gun.
Put it all back together and you're done. I use blue loctite most of
the time, although some guns have gone without, with no ill effects.