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Thread: 2250B Crosman new valve stem

  1. #1
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    2250B Crosman new valve stem

    Hello, was looking to see if anyone had tried the Crosman new valve stem for their 2250B. Is it is worth it and does it increase the FPS?

    Enjoy every day, you never know when it will be your last!

  2. #2
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    is this a new crosman part ? Or aftermarket ?
    Got a link or description of the differences ?

    In the UK power is more more limited by the temperature for CO2. Getting some power is fairly easy, but shot count plumets.
    Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.

  3. #3
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    Quote Originally Posted by Shed tuner View Post
    is this a new crosman part ? Or aftermarket ?
    Got a link or description of the differences ?

    In the UK power is more more limited by the temperature for CO2. Getting some power is fairly easy, but shot count plumets.
    Modified original part from evilnay.
    Enjoy every day, you never know when it will be your last!

  4. #4
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    is that the guy who charges stupid prices for valve tunes and valve pinning and also is doing the reduced stem shanks which is nothing new really

  5. #5
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    Quote Originally Posted by --ped-- View Post
    is that the guy who charges stupid prices for valve tunes and valve pinning and also is doing the reduced stem shanks which is nothing new really
    Seems to fit the profile:-)
    Enjoy every day, you never know when it will be your last!

  6. #6
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    so reducing the valve stem diameter around the port will increase gas flow and raise fps, at the expense of gas consumption, yes.

    but you are simply inputting more energy into a not particularly efficient system. The first mods I do to a 22xx are transfer port sealing (they normally leak) and an SSG, which noticably improves efficiency. A 19" barrel helps a lot too, but it's a bit long.

    HTH - JB
    Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.

  7. #7
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    reducing the stem shank is one of the little tricks that add fpe but it works best when you do the full package of mods starting with flow into the valve followed by volume of the valve followed by reducing the valve spring tension (i tend to skip this bit as it can add to hammer bounce)
    you then have gas flowing the stem and reducing the stem where it sits in the valve exhaust follwed by angling the port to 20*(works best if your making a valve from scratch)
    you then get tp increase to 4.2mm with better seal(i like to mill the tp seat flat and use a gasket top and bottom like the p-rod pistol) followed by barrel port to 4.2mm(.22)

  8. #8
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    Quote Originally Posted by Shed tuner View Post
    so reducing the valve stem diameter around the port will increase gas flow and raise fps, at the expense of gas consumption, yes.

    but you are simply inputting more energy into a not particularly efficient system. The first mods I do to a 22xx are transfer port sealing (they normally leak) and an SSG, which noticably improves efficiency. A 19" barrel helps a lot too, but it's a bit long.

    HTH - JB
    And take coil off the hammer spring?

  9. #9
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    Quote Originally Posted by Berber View Post
    And take coil off the hammer spring?
    not if you fit the SSG
    Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.

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