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Thread: pv question

  1. #1
    vomitspot's Avatar
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    pv question

    im about to have some cylinders bore and plated to 87mm
    after this is done whay is everyone doing to the pvs?


  2. #2
    Moderator OsideBill's Avatar
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    PV's have to be adjusted to clear the pistons .015" min when fully closed and blended to match the exhaust port when fully open.

  3. #3
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    jeff curry says i dont even need to put them in but i really wanted another opion
    this will be on a 2 cylinder in a standup

  4. #4
    Moderator OsideBill's Avatar
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    All I can say is they hit a lot harder with them functional, the ones GK did where they pinned them open are not even close on the bottom end. Give professor Lowell a call he will school you on these. I guarantee it will make sense after talking to him.

  5. #5
    vomitspot's Avatar
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    i understand the theory
    was gonna le tjeff machine my gas valves to match the bore
    thats when he told me i didnt even need them and it was a waste of my $
    he told me the pv really dont make any difference in 87mm 66e motor
    im currently running 84mm 60t npv cyl

  6. #6
    Moderator OsideBill's Avatar
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    Never worked with Jeff, If he is doing your motor I say go with his advice and guidance, ultimately he is responsible for the outcome.

  7. #7
    I had mine done. Lowell did by 87mm and matched the valves to them. Its like a work of art!!!!

    Have not tested the ski yet though. In a month or two will have numbers for all!

  8. #8
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    all im doing is bb no porting
    top end isnt a factor as its in a stand up and anything over 1/2 throttle is so damn squirly
    i have read where people pin the valves open

  9. #9
    Moderator OsideBill's Avatar
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    If its bottom end you want, pin them in the down position.

  10. #10
    You can get the power valve controller from pro-tec and just have the valves come on at a really high rpm. This way you don't have to mod the engine...

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