Neither number is correct you can’t have a poppet smaller than the throat and the throat would be insanily huge. I would check them
Quote from: oldpro on October 25, 2018, 11:09:45 PMNeither number is correct you can’t have a poppet smaller than the throat and the throat would be insanily huge. I would check them Ok now what’s the caliber and what FPE are you set at?Hahaha! I was thinking about the inside diameter of the valve housing,lol. The valve seat is made of PEEK opened up to .200(throat) and the poppet/valve pin is .225-ish. Sorry about that
Mike D, have you made any more progress on the cobra install on your P15?? I'm really curious to see if you made any headway there.Sadly, I've made almost no headway. I made changes to have it vent outside of the valve body, into the regulator plenum. I drilled out the screw that secures the tube to the cobra chamber, and inserted a tube from a small Triflow bottle. A #68 bit is a very snug fit in that tube, so the vent is right at .031. All I managed to accomplish was needing my HS turned up,lol! I'm pretty sure the cobra spring is working, given the fact that I had to increase the HS to reach the same velocity. I gained a couple of shots from my last attempt, but I still can't beat my best tune with a conventional valve spring set up. Just thinking out loud here, but I think it would work better with a higher reg set point. Right now, it is at 125 bar. I wonder if turning it up to 130-135 bar will increase the effectiveness of the cobra tech. That would likely give a larger pressure differential between the tube and the rest of the valve. Of course, the extra pressure would make the valve close faster too. I feel like I'm just at the point of diminishing returns with it right now. A larger plenum sure wouldn't hurt either, but I'm only working with a 165cc cylinder before the regulator. Either I'm missing something, or the cobra tech just isn't the best option for a .22 Flash at 30fpe. Any input or advice is most definitely welcome from anyone that wants to chime in! I made the cobra tech work in the gun, but it may be better suited for a lower power tune in this case? Currently, I'm thinking I'm at the point of going back to a conventional valve spring for this gun.
Quote from: oldpro on October 19, 2018, 11:47:21 PMQuote from: Kerndtc on October 19, 2018, 11:37:40 PMMy first attempt. This is my gauntlet valve, up until now it had factory porting. Now it's .233 bore with the cobra mod. Once I get the SSG done I'll give it a go! Perfect gun to try it on. I would try it Cameron before SSG so you know what percentage each device contributedI have such a hard time not doing things all at once. Luckily the SSG I like to put together arevery simple to install after removing the rear tube cap and the spacer. Maybe I'll shoot it with the new valve then drop in the SSG. Cam
Quote from: Kerndtc on October 19, 2018, 11:37:40 PMMy first attempt. This is my gauntlet valve, up until now it had factory porting. Now it's .233 bore with the cobra mod. Once I get the SSG done I'll give it a go! Perfect gun to try it on. I would try it Cameron before SSG so you know what percentage each device contributed
My first attempt. This is my gauntlet valve, up until now it had factory porting. Now it's .233 bore with the cobra mod. Once I get the SSG done I'll give it a go!
Subscribed, I was wondering about this but dared not ask
Quote from: Tweeter on February 11, 2018, 03:12:49 PMSubscribed, I was wondering about this but dared not ask I’m probably missing what’s right in front of my face but I can’t figure out how to subscribe to a thread??? Many times I have wanted that option including this time. Can anyone tell me what I’m missing? Thanks.
Quote from: Dbez1 on October 26, 2018, 11:56:22 AMQuote from: Tweeter on February 11, 2018, 03:12:49 PMSubscribed, I was wondering about this but dared not ask I’m probably missing what’s right in front of my face but I can’t figure out how to subscribe to a thread??? Many times I have wanted that option including this time. Can anyone tell me what I’m missing? Thanks.Dave, click on the "Notify" to subscribe to a thread then click "ok" in the pop-up You will then receive an e-mail notification on new post.
Ok Donny heres the problem i see its a matter of flow restriction you have a small valve being pushed to its limmits so you have to dwell it long to make the power your getting this means using the cobra tech will yield very little to no use to your set up and likely will have negative effects. i would open up the power train to breath better before going forward(exhaust port. TP. BP etc.) When i seen the pics of the valve poppet I knew right away this was likely a no go. The only way to make it work would be to put a short stiff spring inside the Cobra chamber,
Donny I had a quick look at my BT65 valve and I think the volume inside the valve is too small . That is unless you move the cobra tube to the outside and thread it into the spring retainer. This would mean much longer valve stem or a two piece that looks like a dumbbell . This could allow for a much bigger diameter tube and would help with shortening the dwell.
Donny-- unfortunately I have nothing more to add at this time. Hurricane Michael had been a distraction, my parents live in St Joe Beach and were displaced by the storm......thank you for continuing to share your efforts and findings. Hopefully I'll get back to testing sometime in upcoming months.
Quote from: oldpro on October 26, 2018, 02:05:31 AMOk Donny heres the problem i see its a matter of flow restriction you have a small valve being pushed to its limmits so you have to dwell it long to make the power your getting this means using the cobra tech will yield very little to no use to your set up and likely will have negative effects. i would open up the power train to breath better before going forward(exhaust port. TP. BP etc.) When i seen the pics of the valve poppet I knew right away this was likely a no go. The only way to make it work would be to put a short stiff spring inside the Cobra chamber,Boooo, not what I wanted to hear,lol! No, I figured as much already with my testing. I knew it was likely a no go when all I was achieving was the need to increase the HS. The Cobra isn't meant for this gun, unless at a lower power level maybe(or on a .177). If I had a lathe, I could fix that small poppet issue, but... Trust me when I say, everything is opened up as far as I can safely take it. It can do 60fpe with that short barrel in .22, so it is breathing quite well. I'll just be happy with my 36 shots at 30fpe with the conventional valve spring, and call it a learning experience Quote from: Hobbyman2007 on October 26, 2018, 07:38:22 AMDonny I had a quick look at my BT65 valve and I think the volume inside the valve is too small . That is unless you move the cobra tube to the outside and thread it into the spring retainer. This would mean much longer valve stem or a two piece that looks like a dumbbell . This could allow for a much bigger diameter tube and would help with shortening the dwell. That could work, but I don't have the means to make that part Another solution may be to machine out the interior of the valve assembly to accept a larger poppet/valve seat/cobra tube? I know I've seen others doing really high power tunes on the BT valves did that. If the interior of the valve were opened up, then you could use a larger valve seat, poppet/valve pin. I'm thinking it would take some serious HS to crack that though. Just thinking out loud. Hopefully, you'll come up with something Quote from: mackeral5 on October 26, 2018, 05:09:36 AMDonny-- unfortunately I have nothing more to add at this time. Hurricane Michael had been a distraction, my parents live in St Joe Beach and were displaced by the storm......thank you for continuing to share your efforts and findings. Hopefully I'll get back to testing sometime in upcoming months.Sorry to hear that man! Hopefully, they'll get things back on track soon, and so will you
Travis, the stiffer spring in the cobra tube would surely help. However, with the way the Flash cocks, I'm afraid it will make for a very stiff hammer spring setting for that gun. I think the valve is already closing too fast to make the 30fpe without significant hammer strike and no gain in shot count. It wouldn't be all that fun to shoot, given the straight pull bolt. The extra cocking effort wouldn't be worth the extra(if any) shots in this case to me. As I mentioned earlier, the "cobra effect" is definitely happening, but it would be far more beneficial at a power level of 25fpe or less in this particular gun. My gun has .187 porting all the way through, and the PEEK valve seat is at .200. I don't have much more room to make it breath any better. I could open the seat up to .210, but that is about all I have left. I think I've just hit the wall for what I'm willing to accept with HS settings vs shot count gains. I'm getting an efficiency of around 1.4 with the conventional valve spring, so even if I got it up to 1.6, I'd only be gaining 4-5 shots. I could be wrong, but I feel like the law of diminishing returns has come and smacked me upside the head on this one,lol. It seems the way the hammer/hammer spring set up is in this gun, combined with the valve design, is just working against me. Please correct me if I'm off course though! I wouldn't mind one bit being wrong on this one. Either way, I REALLY APPRECIATE your, and everyone else's input and advice on this!
Question is ... are you seeing better efficiency, quieter shot cycle ... loss of power at equal HST to non cobra ... etc ?
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