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Cams without porting?

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  • Cams without porting?

    My new motor has Brand New, yes NEW cylinder heads, so the valves and seats are sealing perfect but the heads are stock. Well apparantly there is minor porting done to the exhaust but im sure its like stock. Anyways im wondering if cams are worth my time if im not going to port the heads? I am NOT pulling the heads off this brand new fresh rebuilt motor. But i am thinking about throwing some cams and valve springs in with the heads on in the engine bay, just wondering if porting the heads is really a must with cams. I have ported a few sets of VG heads so i know how shitty the castings are in the bowls of the ports, pretty nasty and really needs improvement, but is $250 for cams and springs worth it still if the heads are stock?

  • #2
    yes.... more duration to let air in and out

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    • #3
      Cams yes,

      Springs maybe;

      Reason being firstly that cams are not entirely "about" increasing airflow, but increasing airflow and efficiency in the RPM range where it is needed. Another way to say it is that they accomplish more of a volumetric efficiency change through degreeing than they do an airflow change through lift. Combine the two and you see better gains. If they are good stock springs you might not have any issues with valve float unless you run a lot of boost (which tends to cause intake valve float far sooner than exhaust for obvious reasons). Cam manufacturers will always recommend an aftermarket spring, but it's not always needed.

      Another way of looking at it: If you plan to do the springs, they are sure a hell of a lot easier to do with the heads off the car anyway... and at that point you might as well pull the valves and complete the port work he started.

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      • #4
        Well if they are brand new heads then the springs are brand new and they should handle 7K no problem. You say good condition ones will do it, well whats better than brand new ones! I will get cams and try it out at least and hope i dont float the valves. I probably wont rev past 6500-6800RPM. Think cam gears are in order for me?

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        • #5
          roastin300 wrote: Well if they are brand new heads then the springs are brand new and they should handle 7K no problem. You say good condition ones will do it, well whats better than brand new ones! I will get cams and try it out at least and hope i dont float the valves. I probably wont rev past 6500-6800RPM. Think cam gears are in order for me?
          That's based on Ken's experience with simialr cams as me and good stock springs.

          Adjustable cam gears are your decision, but I like the difference advancing them slightly (with the 270-62H grind) made. I'm sure you saw the dyno graph of the difference...

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