Cheater cam or comp cams XFI extreme truck

Discussion in 'Performance & Fuel' started by drumm14, Feb 16, 2011.

  1. drumm14

    drumm14 Rockstar

    I am stuck between two cams, the XFI extreme truck cam from comp cams
    dur @.5: 212/216
    Lift: .607"/.621"
    RPM Range: 800-5200
    LSA: 115
    or the thunder racing cheater v.3 camshaft
    117 LSA.
    Off Idle-6800
    Any other cams out there that would be better?
  2. stephan

    stephan Rockstar 4 Years 5000 Posts

    The specs are so close on those that I don't think you would ever notice the performance difference between them. Their claims that they work right off idle seems a bit optimistic though. Cams with +.6 lift usually don't start working untill 1,700 -1800+ RPMs. You may see a dead zone untill around 1800-2000 RPMs. Not a real flat spot, but just kind of lazy getting it going. Did either manufacturer mention needing heavier springs or checking valve to piston clearance with these?
    I don't know if Edelbrock is any better performance wise, but they are a little more realistic about the lower end of the RPM range where their cams start working.
  3. drumm14

    drumm14 Rockstar

    both said i would need to upgrade springs and push rods due to increased lift.
  4. stephan

    stephan Rockstar 4 Years 5000 Posts

    I don't know what engine or heads you have, but if you have the pressed in rocker studs, (which most stock factory heads have) I would ask which ever cam company you go with if they recommend pinning the studs or replacing them with the screw in rocker studs since stronger valve springs have a tendency to pull the pressed studs out.
  5. drumm14

    drumm14 Rockstar

    Thunder racing said that they recommend using the stock studs and rockers.
  6. jwco5.3

    jwco5.3 Rockstar 100 Posts

    buy both, send one to me.... and we will drag race. Whoever wins, got the best cam?
  7. silveradotrailblazer

    silveradotrailblazer Epic Member 5+ Years ROTM Winner 5000 Posts

    Is that CompCam the cam Comp tech line recommeded? I'd go with what the Comp techguys say. The rocker arm assembly on the Genlll engines don't have rocker studs. The complete rocker assembly is mounted with 8-mm bolts, you remove them with a 8-mm hex head and the entire assembly comes off. I recomend a book called How to build high performance LS1/LS6 V-8's. You can get the book from any GM dealer. It's part # 88958786. It has loads of info including truck parts and dyno numbers.
  8. drumm14

    drumm14 Rockstar

    So after tons of research and taling to four seperate companies I ended up buying comp cams 212/218 .558/.563 lsa 114. All four places recommended this cam over their custom cams or any other manufacturer.

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