Mid Range surge
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Mid Range surge

  1. #1
    Member 00 CP's Avatar
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    Default Mid Range surge

    I'm getting a surge, almost a miss, between 3200 and 3800 rpm.
    The motor is a 508 BBF, 12:1, .715" lift mechanical roller, timing set at 34 total. Rings, bearings, timing set, valve job, lifers and rockers this season, but the bottom end is basically the same combo as last year. What's new is the Trick Flow intake, 1150 Dominator and scoop. 86 (92's from factory) and 102 jets with a 5.5 power valve (factory). I'm thinking the power valve should be a 3.5 (as in the 925cfm carb I replaced) or maybe a 2.5. There aren't any vacuum ports on this carb or manifold. Hoping the experts can help me out here, not sure the PV would even cause this problem. Thanks

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    Member 00 CP's Avatar
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    Nobody has any ideas?
    Should have mentioned that the ignition is MSD6A box with billet distributor, new cap, rotor, wires, plugs. Motor runs fine at lower RPM's and at WOT.

  4. #3
    mo balls than $cents$ IMPATIENT 1's Avatar
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    Prob 3 circuit dominator carb right? If so it needs some tuning

    Dare to be different, if it turns out great you can claim you planned it that way.

    Jetboatperformance.com

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    149 BGJ-Willis Power 540 willis's Avatar
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    Quote Originally Posted by 00 CP View Post
    I'm getting a surge, almost a miss, between 3200 and 3800 rpm.
    September 25, 2014

    Hello People

    Save yourself some time:
    C&J Engineering, One time and the problem is solved

    Willis

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    031 RIVER4FUN's Avatar
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    Bruce, check out the C&J thread. Send it up to John. It'll be perfect when ya get it back. When I bought my 1050s brand new I didn't even open the boxes. Sent them straight to C&J
    I may be growing older, but I refuse to grow up!

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    Member 00 CP's Avatar
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    Default Thanks

    OK, I'm sold. Will be calling John tomorrow.
    Thanks for the advice.

  9. #7
    CP-Carrillo Piston Maker's Avatar
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    Quote Originally Posted by willis View Post
    September 25, 2014

    Hello People

    Save yourself some time:
    C&J Engineering, One time and the problem is solved

    Willis
    John says thanks Willis.

  10. #8
    149 BGJ-Willis Power 540 willis's Avatar
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    Quote Originally Posted by Piston Maker View Post
    John says thanks Willis.
    September 25, 2014

    Hello People

    Tell your dad I said hi and are the both of coming to the races?

    Willis

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    Quote Originally Posted by willis View Post
    September 25, 2014

    Hello People

    Tell your dad I said hi and are the both of coming to the races?

    Willis
    I will. I'm unable to attend, but he may....not sure yet. Good luck to everybody though.

  12. #10
    149 BGJ-Willis Power 540 willis's Avatar
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    Quote Originally Posted by Piston Maker View Post
    I will. I'm unable to attend, but he may....not sure yet. Good luck to everybody though.

    Thanks

  13. #11
    senior member turbo wog's Avatar
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    Quote Originally Posted by 00 CP View Post
    I'm getting a surge, almost a miss, between 3200 and 3800 rpm.
    The motor is a 508 BBF, 12:1, .715" lift mechanical roller, timing set at 34 total. Rings, bearings, timing set, valve job, lifers and rockers this season, but the bottom end is basically the same combo as last year. What's new is the Trick Flow intake, 1150 Dominator and scoop. 86 (92's from factory) and 102 jets with a 5.5 power valve (factory). I'm thinking the power valve should be a 3.5 (as in the 925cfm carb I replaced) or maybe a 2.5. There aren't any vacuum ports on this carb or manifold. Hoping the experts can help me out here, not sure the PV would even cause this problem. Thanks
    probably lean if it is missing. you want fuel earlier from the power valve not later .try something like a 6.5 or higher, not a 3.5. that holds the fuel back until higher rpm/less vacuum.

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