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  1. #1
    Napkins........ I Fly a Starship seajm's Avatar
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    GP 1200 compression question

    Just bought a Cool Head by Pro design for my 99 GP1200 npv. I'm trying to achieve the 140psi to 160psi range. The head came with 30cc domes said to bring me up to 215psi. Does anyone have any input to what size domes I should get to achieve my desired compression? By the way the engine is a stock bore 1200 non pv.
    Thanks


  2. #2
    Hockey369's Avatar
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    On my ada head, 42cc domes put me around 150psi range. I would guess it would be the same for the Cool Head.

  3. #3
    Napkins........ I Fly a Starship seajm's Avatar
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    Quote Originally Posted by Hockey369 View Post
    On my ada head, 42cc domes put me around 150psi range. I would guess it would be the same for the Cool Head.
    Yep! Just got the same answer from Pro Tec. Thanks!! Lucked out aswell, They are tooled and cutting domes right now!!

  4. #4
    Flying Scotsman's Avatar
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    Pro tec and Pro design domes
    Pro design 150 psi 44cc
    Pro tec 150 psi 42cc

    Dont ask me why all I can figure is they measure them diferently.
    I have Both heads and domes are interchangeable from one to another.

  5. #5
    Napkins........ I Fly a Starship seajm's Avatar
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    Quote Originally Posted by Flying Scotsman View Post
    Pro tec and Pro design domes
    Pro design 150 psi 44cc
    Pro tec 150 psi 42cc

    Dont ask me why all I can figure is they measure them diferently.
    I have Both heads and domes are interchangeable from one to another.
    I lucked out with Pro Tec, when I called to check pricing they were retooling to cut domes. Pro Design would not answer their phone!

  6. #6
    Flying Scotsman's Avatar
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    34cc
    215psi
    200psi 36cc
    195psi
    185psi 38cc185psi170psi 40cc170psi160psi 42cc160psi150psi 44cc150psi140psi

    $40 a pop

  7. #7
    Napkins........ I Fly a Starship seajm's Avatar
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    Quote Originally Posted by Flying Scotsman View Post
    34cc
    215psi


    200psi 36cc
    195psi

    185psi 38cc185psi170psi 40cc170psi160psi 42cc160psi150psi 44cc150psi140psi

    $40 a pop
    Pro Tec $39.99 a pop ordered 3!!

  8. #8

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    I thought the 99 had the powervalves

  9. #9
    Napkins........ I Fly a Starship seajm's Avatar
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    Quote Originally Posted by akjose View Post
    I thought the 99 had the powervalves
    Nope!

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