Marauder with .25" PEEK Poppet

[3BI5]

Pointed cone shape on the pressure/spring side or on the throat side? I'm curious would a pointed cone shape on the pressure side make a difference on the force needed to knock the valve open? As pressure is supposed to apply an even force perpendicular to the surfaces it affects, does the poppet head shape affect the force needed to open it against the pressure?

[ackuric]

Oh man I can't help but tinker...

Tossed in the .25 poppet again on the glued # 2 valve...not sure if it holds air but

Same settings as .3" poppet, same spring/ect...

I went from 500 fps to 700 fps on jsb 25.4. That is 14 FPE to almost 28 FPE....I am just in aww how little spring cracks this valve...I will defniitely be trying the .25" poppet again with alterations

That is with the lighter 31 gr hammer (35 gr with striker + cocking lug)

[triggertreat]

Pointed cone shape on the pressure/spring side or on the throat side? I'm curious would a pointed cone shape on the pressure side make a difference on the force needed to knock the valve open? As pressure is supposed to apply an even force perpendicular to the surfaces it affects, does the poppet head shape affect the force needed to open it against the pressure?

Both sides is really what I was thinking. ♢


                                                                   

[ackuric]

Pointed cone shape on the pressure/spring side or on the throat side? I'm curious would a pointed cone shape on the pressure side make a difference on the force needed to knock the valve open? As pressure is supposed to apply an even force perpendicular to the surfaces it affects, does the poppet head shape affect the force needed to open it against the pressure?

I always question that myself and assume the only benefit would be against the drag maybe as it opens? Since the air rushing by is going well over 1,000 FPS I would imagine drag laws apply to the poppet head, but then again you would potentially reduce the closing force so idk how that poppet head would behave without extensive testing personally!

I do know that my .25" poppet both have less pressure against it while fully seated, AND it has less drag on it when opening. Mine is shaped like stock as you can see in the pictures but much smaller.

Testing for leaks on Valve #2 again now but really not holding my breath anymore than I don't think it's gonna hold air. But I do have valve # 3 on order to attempt this again with smaller portings!

[ackuric]

Pointed cone shape on the pressure/spring side or on the throat side? I'm curious would a pointed cone shape on the pressure side make a difference on the force needed to knock the valve open? As pressure is supposed to apply an even force perpendicular to the surfaces it affects, does the poppet head shape affect the force needed to open it against the pressure?

Both sides is really what I was thinking. ♢

                                                                   

IMO if we could get a perfect seal with metals like a car valve, that would be most ideal for flow (ie: flat and kinda the shape you describe except inverse on the exhaust side to allow the air curtain/bubble more room/flow) but that is just IMO.

[ackuric]

Here is what I would imagine would be pretty stellar...

.225" poppet head made from hardened steel

.42" OD and .205" ID peek (nylon pictured) washer to seal against

With .180" porting and .06" valve stem reduction, that thing would crack open with 3-5 lbs of spring energy, and should be VERY snappy...hmmm! Tempting to try but peek washers need to be bought in bulk, need to find a local source! I would love to try this...

[3BI5]

And if you could also use say 30° or 45° (depending on lift/valve head size relation) valve seat angles like in cylinder heads, that would also flow some air. A poppet valve with 0° valve seat angle like most air gun valves use are simply a disastor for air flow.

[ackuric]

24 hrs on the .25" peek poppet, 100 + shots even with the .04" stem, ZERO signs of failure so far and all is holding air

Gonna keep this puppy in for awhile and stress test it...

This a glued / moved forward seat with a .25" peek poppet on .216" porting.

Poppet holds air down as low as 1k psi which is the lowest so far I've tested it

[ackuric]

This poppet is still holding up! New updates are as follows...

I decided this poppet was REALLY easy to crack open, so I tossed a 21 (25 grams with striker + cocking lug) gram hammer behind it instead of my old 31 gram hammer.  (35gr loaded)

7.5 lb spring = 20-30 FPE
10.5lb spring = 30-45 FPE
13 lb spring = 45-55 (max I've tested) FPE

Gun seems quite a bit quieter, certainly ZERO negatives from doing the above, have yet to run any long strings to test efficiency but that isn't what I am after...

25 cal with a .25" peek poppet and a 25 gr hammer, 25 cc plenum extension...just having fun with the play on the number 25 and so far its working out!

[triggertreat]

I can see how the .25 poppet head would make for less hammer energy requirements, but you only have a 0.025 overlap on the seat.  Not sure about the longevity of the seal/poppet with that small of an overlap.  You maybe digging the poppet out of the throat soon, lol.  At least you get a gold star from me for your efforts if it does happen to fail.

[ackuric]

I can see how the .25 poppet head would make for less hammer energy requirements, but you only have a 0.025 overlap on the seat.  Not sure about the longevity of the seal/poppet with that small of an overlap.  You maybe digging the poppet out of the throat soon, lol.  At least you get a gold star from me for your efforts if it does happen to fail.

a .01 sealing margin is recommended for peek poppets. Actually...but to pull that off by hand imo deserves a gold star considering it holds a seal

I've inspected the poppet and there is zero sign of defect or failure.

There is a max of 100 lbs being pressed against the poppet when the valve is closed

My sealing margin is at most is .0125" which I left the extra .0025 because of me doing it by hand.

I have my ports restricted a bit as well to around .211" currently with a reduced tp as that throat only flows sufficiently for it, I would have to push the throat out to .23" to flow well for my max porting of .215/.216" which I don't feel entirely safe doing!

It probably took me around 10 attempts to get a hole drilled perfectly (by eye) centered into a .25" piece of material...talk about tedious! I was determined though to make my own poppet by hand and the end result of saying "hey I did it" feels very good, I am far from as accomplished as many of the guys that have been around for years building/tuning pcp's and have many of them to thank for the knowledge I have obtained reading around on forums or pming questions

[ackuric]

To put in perspective I took a stock poppet down to .29" on the .265" stock throat and the poppet showed signs of failure (bulged out some on the outer diameter)..Peek is tough and the throat itself won't fail

The above showed signs of failure just after 10 shots at medium power, the current peek poppet has been from 12-58 fpe for 500 shots, removed and examined, and holds true shape/form

[mann]

Interesting seems like you can get some big gains with light hammer and spring by reducing poppet head size looking forward to hearing about more testing and also if different shape would change how hard the valve opens will be following the post

[ackuric]

Interesting seems like you can get some big gains with light hammer and spring by reducing poppet head size looking forward to hearing about more testing and also if different shape would change how hard the valve opens will be following the post

On a stock unmodified Marauder valve with stock poppet I wouldn't reduce it further than .32" personally. When going to delrin / peek on the same stock valve you might get away with .28" safely, all being said if you don't alter the valves seat.

I modified my valve by adding a washer that was .418" OD x .275" ID x .04" thick on to the existing valve seat with a thin layer of adhesive (I chose a plumbing adhesive that can withstand 3500 psi and doesn't dry completely hard, although its compression is minimal as its layer between the old seat + new seat is less than .01" therefore cannot compress further than that and likely doesn't compress/decompress more than .001". I used that as an adhesive to avoid a dry/hard one that would crack upon impact of valve seating over time. Hopefully it holds up...The old seat supports the washer and was drilled out to .23". This is in a rifle that operates at a max of 2000 psi and I would likely not trust it if it were unregulated and seeing pressure as high as 3k which would increase the force against the poppet by 50%, most prone to failure would by my .04" valve stem, or the adhesive I used.

[mann]

I agree with it possibly failing at higher pressure in a unregulated gun . By seeing your tests there is definitely room for improvement over the stock valve set up

[ackuric]

The .25 PEEK Poppet with a .04" stem is still holding up, getting smacked around by a 42 or 25 gram hammer making 12-60 FPE. Ton's of shots on this stem...I hope this thing holds up forever!

.25" poppet on a .226" valve seat allowing .012" sealing margins with both valve seat modification and poppet done by hand! I wouldn't challenge anyone else to try attempting this as I took a lot of care to, and I'm likely the only guy running around with a .25" poppet on a .25 caliber marauder, although I would certainly recommend attempting this in .177 or .22!

I attempted to open up the seat to .23" on the original valve I did this modification to and could NOT for the life of my obtain a seal (accidentally went further than .23"), so I began with a new washer/seat on my original valve...I have made a custom .226" valve seat work twice amazingly in two separate valves, feels very rewarding to accomplish!

The .226" seat with a .04" valve stem limits my ideal porting to around .212" so this new valve is ported only to .212" currently, although my barrel port is .212" x .238" and can take a .225" port I find too much enjoyment out of the .25" PEEK poppet to currently attempt bigger ports with another valve.

I have 0 pellet loading issues with polymags, jsb 25.4, and jsb 34 mk ll's with my .212" wide barrel port.

[mann]

You would think there would be an ideal throat size poppet size where you could reach ideal power with little effort . I wonder if it would scale down farther as far as smaller throat equals smaller poppet and would be easier to open but create same amount of power until the throat is to small to flow the air . It is cool that the spring doesn't have to be 14 lbs to make alot of power and that's what I'm trying to say is do you think it could get any lighter or more efficient. Idk

[ackuric]

You would think there would be an ideal throat size poppet size where you could reach ideal power with little effort . I wonder if it would scale down farther as far as smaller throat equals smaller poppet and would be easier to open but create same amount of power until the throat is to small to flow the air . It is cool that the spring doesn't have to be 14 lbs to make alot of power and that's what I'm trying to say is do you think it could get any lighter or more efficient. Idk

Pretty much was my goal and intention on this modification, resulting in MUCH lower cocking efforts even when coupled with light weight hammers, the material I am using doesn't compress much (PEEK) and the throat/seat area is smaller than stock and the force applied against .25" surface area is only 100 lbs @ 1925 psi...when compared to a stock throat that is .26" seat area with a material that compresses a lot more than PEEK and with a .34" surface area even at only 1925 psi that poppet has 180 lbs of force against it...at stock unregulated that .34" poppet has an average (@ 2500 psi) of 230 lbs against it. I am well under half that which requires half the hammer spring even with a much lighter 42 gr hammer.

I think PEEK is the cats meow when it comes to poppet material. Coupled with smaller seats + poppet head surface area it's a win-win-win.

You could make the seat area smaller but then you'd restrict power, which would make it easier to open...but marginally so compared to the length I've gone over stock.

-.34" poppet reduced to .25"
-Material changed to PEEK from stock
-Seat reduced to .23-.25" over stocks .25"-.265".

If you wanted only say 40 fpe MAX then you could go smaller...

I only need 10 lb of spring to hit 58 fpe and 7.5 lb of spring to hit 50 fpe currently, with a slightly heavier hammer I could reduce the spring effort much more, say with the stock  78 gr hammer I likely could use my 6 lb spring to hit 58 fpe lol.

[mann]

So I thought the throat diameter was around .200 on stock valve so the seat is .050 to .065 larger and your seat area is .030 to .050  . I'm just trying to picture it couldn't you go smaller at least in theory or am I missing something thanks for helping picture it

[ackuric]

So I thought the throat diameter was around .200 on stock valve so the seat is .050 to .065 larger and your seat area is .030 to .050  . I'm just trying to picture it couldn't you go smaller at least in theory or am I missing something thanks for helping picture it

Stock throat is .2" but the seat is around .26"....My throat is .226" on a .25" poppet which allows for a max of .024" seat area / 2 which is .012" per side of poppet.

You could reduce the seat area down to .22" with a .22" poppet but that would limit porting to around .1875" on a .2" throat...and as I said its not that much of a difference considering the reductions I have already done are much greater over stock...I wanted to take advantage of my seat being moved forward with greater ports which I can run .212" on this valve with the .226" throat + .04" valve stem....as the throat still flows 10% greater than a .212" port. I took a .25" Peek poppet as far as I personally could by hand, I am certainly not going to try to reduce my port size back down under .2" as that takes half the intent of this project away.

This modification not only allowed a .25" PEEK poppet but it allows porting as big as .225", but to run .225" ports I would need a throat of .24" and a valve stem of .05" and I don't have the right size material to pull off a PEEK poppet that is .275" in diameter to attempt it. On a stock valve going beyond .19" on the valve exit port is risky without getting creative.