cam upgrade questions

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  • bkelley15k
    Junior Member
    • Oct 2008
    • 5

    #1

    cam upgrade questions

    currently running a Schneider 296H .485 lift 242@0.05 106 lobe sep. stock valves double valve springs seat pressure check at machine shop around 135-145 avg head mild ported shaved .100 stock bottom end kb pistons 40 over

    running a short 1/4 mile 3000 off the corner ~7000-7200 end of straight

    After about 10-12 laps valves start to float.. oil pressure starts around 40 and ends up around ~25-20 at end of 15 laps.

    rules are open now so i can go solid or solid roller.. I have about a 3 week wait at the machine shop to decide what i want to do..

    so i guess i have a few questions
    1. Do you think its the hyd set-up causing the valve float, wrong spring setup or oil pressure ect...?

    2. Thought about going with bigger valves. Does anyone sell the oversized valves with the same multi groove for stock retainer or am i stuck paying $300 for valves and keepers from esslinger - single groove.. called racer walsh but they are done selling 2300 valve train parts according to Paul.

    3. if i go to solid or solid roller, considering I'm sticking with stock rods and crank going to keep the rpm at or under 7500, would i benefit much with solid roller over solid flat tappet.. what lift/duration combo would you recommend for either .. would like to use the valve springs i have only 10 races on them.

    4. If i did go with the flat tappet could i run the roller rocker arms if i have them.. would that provide extra benefit.

    Thanks
  • billb56
    Member
    • May 2007
    • 96

    #2
    Three things I would check.

    1. Rocker arm clearance to cam with lifter/damper fully collapsed.
    2. Springs.
    3. Check cam card or call Schneider for the cam you are using for the RPM range of the cam.

    Comment

    • billb56
      Member
      • May 2007
      • 96

      #3
      Went and looked at the Schneider web site for this cam. You may be overreving or weak springs...........

      This is what I found:

      Part Number: 1372
      Grind Number: 296H
      Intake Duration (gross): 296
      Exhaust Duration (gross): 296
      Intake Duration (.050”): 242
      Exhaust Duration (.050”): 242
      Intake Valve Lift*: .485"
      Exhaust Valve Lift*: .485"
      Lobe Separation: 106
      Intake Valve Lash: .000"
      Exhaust Valve Lash: .000"
      RPM Range: 3000-7000 <===========

      Comment

      • car62
        Senior Member
        • May 2007
        • 1579

        #4
        i run that same cam and have in every engine ive built,make sure you have .045 lash with lifters fully collapsed, ive run it as high as 7600 with no problems,just set fast time last night with the same cam and some of the cars in our class have solid cams..., i run mine about 2 degrees advanced with .170 milled off the head...i run the springs that jerry recommends for the cam at installed height of 1.600 and 110-120 pressure,you can find the stock size keepers in single groove form,i have several....feel free to PM me if you have any questions,happy to help out any way i can.
        No matter how hard you try...you cant fix stupid!!!

        If you build it right...it will turn left!!!

        www.raceidaho.com

        Comment

        • bkelley15k
          Junior Member
          • Oct 2008
          • 5

          #5
          Thanks for the help. Billb56 I was thinking that was just the power range for the cam but I could be wrong.

          Comment

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