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Thread: Airflow: Is more ever too much?

  1. #11
    Quote Originally Posted by AndrewTheWookie View Post
    What fps do you shoot at?
    Standard 285-ish range.

  2. #12
    Insider imped4now's Avatar
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    So obviously that valve doesn't rely heavily on the spring to close it quickly. If I remember the CCM valve, it uses a pretty large nylon/Delrin cup seal so perhaps that large area allows it to close quickly using pressure. I've got some tinkering to do, because there's no logical reason my cocker with a larger valve chamber, larger 11/16 ID V2 valve (that works similarly to the Tornado), and ID hammer should be quite short of a case/68.

    Maybe it needs a stiffer valve spring or lighter hammer spring. Hmmmm.
    OlllllllO

  3. #13
    Quote Originally Posted by imped4now View Post
    So obviously that valve doesn't rely heavily on the spring to close it quickly. If I remember the CCM valve, it uses a pretty large nylon/Delrin cup seal so perhaps that large area allows it to close quickly using pressure. I've got some tinkering to do, because there's no logical reason my cocker with a larger valve chamber, larger 11/16 ID V2 valve (that works similarly to the Tornado), and ID hammer should be quite short of a case/68.

    Maybe it needs a stiffer valve spring or lighter hammer spring. Hmmmm.

    Actually, the CCM valve uses a fairly small area, buna o-ring sealing face. I don't think that it does, or even can, close quickly without a lot of pressure behind it.

    There's a pic of it here:

    https://store.chipleymachine.com/val...d-valve-stems/


    I have a RAT valve and it dwarfs the CCM in terms of dimensions. Like a dinner plate vs. a salad plate.

    But the way it's made looks to be very efficient for actually allowing air to get through it, vs. a lot of other designs with larger orifices.


    So there it is. Small sealing face, soft material, soft springs, really efficient.

    Hence the mystery.

  4. #14
    Insider imped4now's Avatar
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    Yeah....I'm curious to see the reasoning, because that goes against the general convention.
    OlllllllO

  5. #15
    That makes two of us!

  6. #16
    Remember that the spring is you mechanical dwell on the valve. If flow is restricted, then you would need to run a softer valve spring, but if flow from the valve itself is sufficient, then it won't matter much. Also, having a huge dump area before the valve also plays a part in it.

    Now, you stated that you have a soft valve spring, what about the hammer spring?
    Have you tried gauging the HPR?
    Have you played around with switching the springs, i.e. taking out this magic combo after setting a specific fill to shot case, then use the various other combos to see where the effect will be.

    Also, if it ain't broke don't fix. There are various stories of whether LP parts or tuning for efficiency and going by "the book" did not gain the "correct" effect, but by chaning things in the equation, got the same if not better results.

  7. #17
    Hammer spring is matched to the valve spring. So both are super light.

    No idea of pressure, but for this next build I'll probably gauge it.

    Haven't played around with it until now, so this is me trying to figure out where the gnomes are hiding.

    I'm certainly not trying to fix it, though admittedly I am trying to improve it in the replication process.

  8. #18
    Quote Originally Posted by Lurker27 View Post
    Depends on the math you choose. And how long the restriction is, etc. The valve orifice is also certainly a bigger restriction than that, so you might not actually see the difference in pressure between the reg volumizer and the valve chamber.

    Generally speaking the volume and flow on that side will always help efficiency for a cocker type system. Especially if you're running a reasonably beefy main spring/hammer combo.

    Almost forgot to ask/clarify:

    It may not matter, but in theory, is it better to have one larger hole going from the VASA to the body, or two smaller holes (creating a manifold)?

    And if a manifold, is it better that both holes are roughly the same diameter, or that one is larger?

    And if one larger, is it better for the larger to be closest to the valve, or the smaller?

    Thanks again very kindly.

  9. #19
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    One large always better unless you're trying to throttle (assuming area match).

    I was gonna ask where you are in relation to the sweet spot. It's possible the streamlined valve profile of the ccm
    Results in lower absolute flow per psi but higher flow per closing force per psi

    Shifts the operating pressure higher.

    Sweet spotting was always more a consistency (self regulation) concern than an efficiency concern, it's possible that it's not the most efficient setup in many hardware combinations.

  10. #20
    Thank you!

    To some of your points, I will be area matching, but am not sure what you mean by 'throttling.' Can you say more about that?

    Also, given that the stock inlet port is kind of limited in terms of where it can go, I may simply have to drill out another hole toward the front of the body.

    If complications are no issue, what about blocking the stock hole and then drilling out the single large hole?

    As for sweet spot, it's right on it.

    Thanks again!

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