Big Chief valve spring problems

Discussion in 'PSI Superchargers Tech Questions' started by overkill69, Jan 21, 2008.

  1. overkill69

    overkill69 Member

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    We run a 540 KB/Olds with 14 degree chiefs and a 14-71 k9 Superman. With 375lbs spring pressure we broke an exhaust rocker stand in two and all the others were bent. Jesel changed the design a little so we replaced all the exhausts and put 400lbs on the seat. The stands are slightly bent again and the #2 ex valve shows light contact with the piston.(.200 clearance) We run an .800 lift Oddy cam to 9000rpm. I'm thinking of welding all the stands together and cranking up the spring pressure some more.
    Anybody have any suggestions?
    Thanks, Mike
     
    #1
    overkill69, Jan 21, 2008
  2. WIZBANG

    WIZBANG Member

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    Just curious, would you be open to sending me a copy of the cam card ?
    I'm curious about the Oddy cam specs ?
     
    #2
    WIZBANG, Jan 21, 2008
    blownfever likes this.
  3. overkill69

    overkill69 Member

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    wish I could..Oddy doesnt give out the card. I do have a hurt cam that somebody could put a cam Dr. on...
     
    #3
    overkill69, Jan 21, 2008
  4. WIZBANG

    WIZBANG Member

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    WOW, I would be all over the hurt cam ?
    Is it for sale ?

    Can I call you ?
     
    #4
    WIZBANG, Jan 21, 2008
  5. Lonnie Houde

    Lonnie Houde Member

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    We had the same problem, until Mike Faucher at Quest Racing made some stands for us out of 4150 pre hard steel. We run 475lbs on the seat, and have NEVER bent any new ones.
     
    #5
    Lonnie Houde, Jan 21, 2008
  6. AnimalCrew

    AnimalCrew New Member

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    We run a KB 532 with Big Chiefs and the Oddy CAM. All of our stands are welded together. We have had our share of valve train problems. We used to have Jessel rockers and stands. They just flat wore out. The cranes we have now have been flawless. ~400 seat and around 1000# over the nose.

    Keeping up with the springs is a must.
     
    #6
    AnimalCrew, Jan 22, 2008
  7. Gary Mangiafico

    Gary Mangiafico Member

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    Rocker Arm Fix.

    Years ago we ran a chevy Wedge motor,

    We fixed our valvetrain problems by switching from Jesel to T&D rockers and Using 1/2" tapered to 7/16" Manton Push rods.

    All but cured our valve train issues.

    Gary Mangiafico
    Absolute Pleasure Racing
     
    #7
    Gary Mangiafico, Jan 23, 2008
  8. WANNABE

    WANNABE New Member

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    We have never run the big chief offset rockers, but lots of the Pontiac 427 stuff, and other similar. (DRCE, Symmetrical port, etc.)
    Welding the stands together is such a help to total stability. If you can find, or have someone make a one piece stand, even better. And as just stated above, significant gains in valvetrain stability when you go with larger, thicker and more steps (tapers) in the pushrod. It does not seem like it would make sense, but it works. Especially in tall deck applications, and very high rpms. Manton also does our pushrods and has been straight forward with knowledge in the realms of size, tapers, and wall thickness to make it work right.
    Never tried the Cranes, but I may after hearing the testimony above.
     
    #8
    WANNABE, Jan 23, 2008

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