Weird valve problem…
I wanted a bit more power and more umph!
Purchased a .25 barrel and hi-flow valve from TT. Had a BJ shroud
Gun has the stock Talon SS spring with an added Condor weight.
Since I don’t have a real heavy hammer weight it was expected to shoot at some point under 3000psi…2550 seems good
This puppy shoots JSB 25g in mid to upper 900’s with the power wheel set on its lowest setting, I can’t slow it down any more with pw. Well I guess I could adjust the tophat but Mid 900’s is fine and a good speed for these pellets, so I’m happy about this, here is the problem.
I fill the tank to about 2550psi..the 1st few shots are lower fps. This is fine I take a few sho0ts to ck sight in anyhow..I guess I could just fill to 2500 or 2400psi and be set. The first 2-3 shots are low fps..then it kicks in..about 20 shots in the mid 900’s..tank down to 1800-1900psi real sweet.
Here is the problem..after those first 20 shots the gun gets real loud, the gun is still shooting in the upper 800’s and going down in fps..but it gets real loud, and I start to feel puffs of air comming out. The more I shoot it the louder it gets, the more puffs of air.
Don’t know why it does not make any sense, gun louder at 890fps and 1900psi than it was at 950fps and 2400psi.
Shoebox refill the tank to 2500 psi..nice and quiet again.. Ideas ???
All Replies
If you are getting too big fps if you put more than 2500 in then A. you have too much wheel, and/or B. the hammer is too heavy.
I would take the extra hammer weight out and have another play with wheel and fill pressures.
Thanks for your input..
Its not a heavy hammer..its a stock condor hammer spacer.
I think the hammer and condor spacer combined come out to around 65 grams.
But if you think it will help..heck I’ll pull that hammer weight out and give it a try..I do want that 950fps if I can get it..
Thanks Pabs
Mrnewbie, filling to around 2400-2500psi is completely normal, most of us do. You have to to keep speeds down. It’s only the guys after big power that fill to 3000 and use a big hammer.
If you are getting too big fps if you put more than 2500 in then A. you have too much wheel, and/or B. the hammer is too heavy.
I would take the extra hammer weight out and have another play with wheel and fill pressures.
Well I have kinda given up on trying to tame this beast down to the 930-950fps range. After running the little shoebox 10 times and going through a few hundred pellets, it just cant be done. I can only shoot at that low a speed with 2400-2500 psi fill with power wheel on 0. Move the power wheel up..and the fps go up..period.
Guess when you throw in a buffed/polished/honed/ported TT high flow valve that is designed for kick-butt performance..thats what its gonna do.
So I’m gonna have to shoot at higher fps..
Here is what I have figured out at this point…
Fill to 3000psi w/pw=6 20 shots in the 980-1030 range.
after those 20 shots, gun loud..puffing air again
Psi now around to 2400-2500..turn pw down to 3.
Another 15-20 shots in the upper 900 range.
Will have to see how that 1000fps affects accuracy..
PAB my man are you listening to this heavy hammer shit and not comming back mate with anything!!!! WTF 😯 😯 😯 Put down the scotch and chime in my man!!!
my theory about heavier hammer was that you use mass instead of preload to open the valve, and while it may still open the valve wide at lower pressure, it seems less so than a light hammer and a tight spring. i like to think that short bursts of a high fill pressure is still closing the valve faster than the hammer spring resisting the closing of the said valve, even when pressure gets lower. my two cents, i like a higher fill pressure using a heavy hammer to open it with minimal preload. any wasted air then is from there not being sufficient pressure to keep the hammer inertia from opening the valve wide. even then, a lower tophat and an o ring under it would help.
If you incremented the fill pressure along with the PW setting you could get some more shots in the same range. You have 24″ barrel? Maybe try a 2600psi fill and turn the power wheel to 1/0. Then go from there. In balance. Change only one at a time.
I’m not even close to being an expert but I put a brass weight/spacer in my talon ss with 21″ barrel and high flo. The wheel was always on 0. I didn’t like that and the hammer hit very hard. I knew it was wasting air. I have an antique lathe and trimmed the weight down till I still have enough weight to open the 177 high flo in my 22 cal. but cutting the length of the weight down gave me my adjustment back. Still shoots hard but can adjust for different pellets.
Pabs you subtle wanker. 🙂 …is the top hat too far out?
I’m pulling that from a dark place….don’t take my word for it. 😉
Even being wrong is educational…teach oh wisened wanker. 😆
Al
[quote=”When the tank drops down in pressure, there is less force to close the valve. The pellet (especially a light, easy to move pellet) has gone but the hammer with the same momentum and spring load it had for the first shot can hold the valve open longer. The result is wasted air making nothing but noise behind the pellet.
I agree with this, so I don’t see how a heavier hammer would help.
Pabs said it all “sippin’ then gulpin”
Remeber, the pw is on 0 and filling to aroud 2500psi.
Think I’ll try this, Fill to 3000psi and move pw up to whatever setting is needed to get 950fps at 3000psi. At some point I would expect the gun to get loud again and the fps to drop. Now turn the pw down a little, causing less force on valve..less gulpin. Maybe I can get another 10shots or so out of it.
Worth a try, fun stuff, glad I have a shoebox
Was sippin’ then gulpin’ too subtle then……. 😆
Hey, I was looking for the AF experts! I’m just a self proclaimed generalist.. 😆
Moneyshot is going where I was thinking the problem might be. I’m not sure it’s actually a problem so much as an observation though.
If you fall off the back of the curve and the velocity has dropped a good bit, do do you still want to shoot or re-fill?
When the tank drops down in pressure, there is less force to close the valve. The pellet (especially a light, easy to move pellet) has gone but the hammer with the same momentum and spring load it had for the first shot can hold the valve open longer. The result is wasted air making nothing but noise behind the pellet.
P.S. about the avatar, i never yet had one, maybe youre thinkin of “nutshot”, the girl bent over with the bullseye on her c**t? THAT was the sweetest avatar ever… 😀 😯 😀
perhaps a little bit, but only because the valve opens wider, if theres more pressure it will close faster. there are 2 things that hold a valve open: back pressure and spring preload.
Thanks Moneyshot…
Would not a heavier hammer keep the valve open longer?
PS, you lost your avatar….I miss her
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my apologies, i guess i assumed that with a tt valve that you were after big numbers. my heavy hammer/ high pressure solution was geared toward that notion. sorry if i fucking offended anybody, i just find that the best solution for the power hungry(myself) is to rely on that big hammer/big pressure to achieve consistency by minimizing the influence of the mainspring and allowing the valve to sort of self regulate. so now that i know you are after something else, ill see my way clear of this post and offer my advise to someone who can use it. 🙄