Page 1 of 7 123 ... LastLast
Results 1 to 10 of 65

Thread: Airflow: Is more ever too much?

  1. #1

    Airflow: Is more ever too much?

    All,

    Am trying to replicate the performance of one autococker in another, and would like to get some engineering eyes on the problem.

    For reference, I have an ID (2k-based) mini fighter that gets a true case per fill (68/4500) and good velocity with the IVG flush, and no volumizer.

    Reg is sweetspotted, but no clue as to pressure.

    Hearing so many others have issues with velocity without a volumizer, I started to think about airflow in the whole system.

    I'm running an Orracle front block/VASA and, in comparison to the standard 2k versions, it's got a cavernous through port, probably double the cross sectional area of a standard 2k mini FB/VASA.

    Am also running a Sidewinder with the largest extender on it, which by itself is a fairly substantial volumizer.



    Again, I want to duplicate the performance of the 2k mini in a pre-2k full body, and so plan to use all the same parts and pressure settings (where possible/compatible).

    Also plan to run a volumizer because ironically the pre-2k full body still has less volume than the 2k mini body.

    This leaves the airflow issue. In the pre-2k body, the choke point is the inlet port. There's only one of it, and it's small, roughly .178" diameter. So probably half the inlet area of a standard 2k body.

    Given that the inlet to the valve chamber is ~.250" diameter, would it be fair to say that the total inlet area to the body should be at least as great as that, to ensure good flow from reg to valve?

    In short, is there any reason NOT to drill a second hole in the body, complete with matching hole in the VASA?

    And if I should drill a second hole, would you recommend making it even bigger, or about the same size as the first?


    Thanks very kindly!

  2. #2
    Insider
    Join Date
    May 2012
    Posts
    1,182
    At that point in the flow system there's no such thing as too much flow. I don't know that the port you reference is restrictive....but if it was me I'd drill it for peace of mind

  3. #3
    Thank you, sir!

    Just to be clear, when you say that you don't know that the inlet port is restrictive, are you saying that, mathematically, it may not actually be an issue, or.....?

    Thanks again.

  4. #4
    Insider imped4now's Avatar
    Join Date
    Feb 2015
    Location
    Indianapolis
    Posts
    354
    Flow aside, you mentioned that it gets a true case per fill from a 68. Have you actually done this? I've been trying to achieve this for quite a while and have since moved to a 77ci tank since I could never do it on a 68.
    OlllllllO

  5. #5
    Quote Originally Posted by imped4now View Post
    Flow aside, you mentioned that it gets a true case per fill from a 68. Have you actually done this? I've been trying to achieve this for quite a while and have since moved to a 77ci tank since I could never do it on a 68.
    Yes, I have, and more than once.

    First time I thought it was a fluke. Filled to 4000 and shot three bags and change.

    Second time I got a good fill, and shot four bags.

    And it consistently behaves this way.

    Wasn't expecting anything remotely close to this level of efficiency (I wanted softness rather than efficiency), and was flabbergasted the first time it happened because the setup did a lot of the 'wrong' things for efficiency, based on popular tuning lore.

    In fact, your thread on velocity was one of the things that got me thinking about this, since we are running such similar setups.

    By far this is the most efficient marker I've ever owned, and part of this project is trying to repeat the results in order to figure out why it works.

  6. #6
    Insider
    Join Date
    May 2012
    Posts
    1,182
    Quote Originally Posted by Menace View Post
    Thank you, sir!

    Just to be clear, when you say that you don't know that the inlet port is restrictive, are you saying that, mathematically, it may not actually be an issue, or.....?

    Thanks again.
    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.
    "So you've done this before?"
    "Oh, hell no. But I think it's gonna work."

  7. #7
    Insider imped4now's Avatar
    Join Date
    Feb 2015
    Location
    Indianapolis
    Posts
    354
    Quote Originally Posted by Menace View Post
    Yes, I have, and more than once.

    First time I thought it was a fluke. Filled to 4000 and shot three bags and change.

    Second time I got a good fill, and shot four bags.

    And it consistently behaves this way.

    Wasn't expecting anything remotely close to this level of efficiency (I wanted softness rather than efficiency), and was flabbergasted the first time it happened because the setup did a lot of the 'wrong' things for efficiency, based on popular tuning lore.

    In fact, your thread on velocity was one of the things that got me thinking about this, since we are running such similar setups.

    By far this is the most efficient marker I've ever owned, and part of this project is trying to repeat the results in order to figure out why it works.
    Impressive. I actually sold my Mini build but kept my Resurrection-FLE based gun, which isn't nearly efficient enough to yield a case from a 68 and I run essentially the same parts as the Mini - mostly ID parts w/AKA regs. The IVG is flush, velocity achieved with about 225 psi.

    I've never been able to shoot a case from anything, including a G6R, Viking, Onslaught, Clone 5 or VIS.

    What components are you running?
    Last edited by imped4now; 11-15-2018 at 01:22 PM.
    OlllllllO

  8. #8
    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.
    Good to know, thank you!

  9. #9
    Insider AndrewTheWookie's Avatar
    Join Date
    Feb 2013
    Location
    Central Coast, CA
    Posts
    374
    What fps do you shoot at?
    I don't know, fly casual

  10. #10
    Quote Originally Posted by imped4now View Post
    Impressive. I actually sold my Mini build but kept my Resurrection-FLE based gun, which isn't nearly efficient enough to yield a case from a 68 and I run essentially the same parts as the Mini - mostly ID parts w/AKA regs. The IVG is flush, velocity achieved with about 225 psi.

    I've never been able to shoot a case from anything, including a G6R, Viking, Onslaught, Clone 5 or VIS.

    What components are you running?
    Quote Originally Posted by imped4now View Post
    Impressive. I actually sold my Mini build but kept my Resurrection-FLE based gun, which isn't nearly efficient enough to yield a case from a 68 and I run essentially the same parts as the Mini - mostly ID parts w/AKA regs. The IVG is flush, velocity achieved with about 225 psi.

    I've never been able to shoot a case from anything, including a G6R, Viking, Onslaught, Clone 5 or VIS.

    What components are you running?

    Here's the breakdown:
    AKA Sidewinder with the long extender
    AKA lightning bolt
    CCM valve
    Inception hammer
    The lightest balanced spring combo CCM makes
    Orracle front block
    Pressure - 280 psi

    Seems like a lot of popular wisdom is to run stiff springs, especially in the valve, but that has never made a lot of sense to me for several reasons. And as efficiency wasn't a priority here, it wasn't a big concern either way. The springs I'm running are crazy soft.

    So either this valve simply likes that combination, or else the conventional wisdom is simply flawed. My guess is that it's a bit of both, and possibly a good bit more of the latter.
    Last edited by Menace; 01-04-2019 at 06:15 PM. Reason: Updated with accurate input pressure.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •