View Full Version : valve modification

03-20-2006, 01:40 PM
Hello everyone, I'm new here. I have read Otter's spyder pages inside and out and searched these forums about modifying the valve on my pilot. I have an '05 red/black pilot ACS, J & J S2 ceramic 14" barrel, Empire Re-loader hopper, Trinity locking feed tube, and polished internals. I want to mod the valve myself. I've read that the trend recently has been more to chamfer the edges of the valve port and smooth it more than re-drilling it. I'm contemplating taking my dremmel to it & beveling (chamfer) the edges of the port; as well as making the hole oval rather than round. I feel that I can leave the pin fairly stock. (Maybe make a second flat side) My ultimate goal is to make the valve more smooth operating versus lowering operating pressures. Has any one tried this type of mod or have any input on my ideas. Thanks in advance, it's a pleasure to be here. :)

03-20-2006, 02:35 PM
Have an extra valve, so one of these days its goona happen, was thinking along the lines of you as in smoothing up the edges to help turbulence, went and pickup up a few dremel tools, and goona have at er soon. i have an extra valve to start with, so if the chamfering doest work, ya can cut more out of the same valve. but if i wreck it then i still got the stock one.

03-20-2006, 04:01 PM
It's good to experiment and all, but don't be cheap, buy a high-flowing valve.

03-20-2006, 04:20 PM
well if it takes me more than an hour, then new valve will be ordered, got a lathe and milling machine to use also, should be quick either way

03-20-2006, 04:36 PM
I get a certain amount of satisfaction from tinkering with my gun myself rather than buying pre-manufactured parts (like when I polished the internals). It's also why I've built 2 kit-kayaks at home, just tinkerin' away. Sparky, please keep me posted as to how the mod works out for you. I plan to mimic the Bandit Bolt brand replacement valve.

Hob Hayward
03-20-2006, 05:04 PM
Haha yeah, I enjoy such stuff too, but the stock valve has problems... the part where the bottom screw comes up to holdit in place causes turbulence etc. Just grab an NDZ hp valve, they're great, and only 25$

Another thing to do, is make your VA high flowing, and drill and tap for a gauge, they look great.

03-21-2006, 12:21 PM

here's the mod if you want it though .. just scroll down a bit ..

03-22-2006, 09:42 AM
Already did the V/A mods before i put reg on, worked out pretty good

03-22-2006, 03:09 PM
That's great Sparky. Did you have to change springs also? What's your velocity? As I said before, I'm hoping to remain stock and just improve smoothness and reliability. (I've only chopped one ball & it was my own fault- didn't have the hopper turned on :rolleyes:) I hope to sit down and work on it this weekend.

03-22-2006, 06:22 PM
with the va mod and the valve mod you will definatly need a spring kit.....i used a 32* kit so i could change the valve spring too.....couldnt get the thing under 300fps without the springs.....def get a spare valve.....you can mod the valve hold screw too if your careful ;)

03-25-2006, 07:08 PM
I modified the valve and pin tonight. I used a dremmel to chamfer the opening of the port and elongate it into an oval. I only did the upper portion not all the way thru to the center (sort of a funnel shape).The pin on the new pilots are different than the ones displayed in Otter's mod-page pics so I only made the one flat side deeper, then polished it. It's only a slight mod so far since I want to try it out after each time I take some off. (you can take off; but you can't put back on!) I'll take it to the local indoor facility and chrono/tune it tomorrow, maybe change the springs.
* Update:
I put in a 32* hard main spring and chrono'd around 290. Felt like it was shooting too "hard" with lots of recoil. It was chopping balls & not shooting straight. Changed to light-valve / medium-main springs and everything's perfect.
I like my set up now, it's good for my 1st marker:
Pilot Acs Red-Black fade
Empire Reloader
J&J S2 Ceramic
32* Spring kit
polished internals
mod'd valve & pin
Trinity clamping feed neck
DYE Sticky 3 Grips

03-31-2006, 05:15 PM
Final Update:
I tried the hard main spring (w/soft valve spring) and it was just too much; the balls curved radically in every direction. So I went back to the medium which is supposed to be like stock, but it feels stiffer. With this set up and the mods it seems to fire quicker and more smoothly with maximum velocity; maybe it's just me though since I really have no way to measure the difference.