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V8 Front cam bearing modification?

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  • Engine: V8 Front cam bearing modification?

    I'm almost ready to have the cam bearings installed on my 289 R2. All the cam bearings have one oil hole. The front cam bore in the block has two. This additional oil passage runs between the front main bearing and the drivers side lifter gallery but also passes through the front cam bore. I'm tempted to drill a small .030 hole in the front cam bearing to add a little extra oil for extra bearing life.

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      • #4
        The oil flow illistration shows a link between front main, cam and both gallorys. Hmmm...


        • #5
          You may notice the flow direction in the schematic..!

          Trying to fix a non-problem. Don't screw with what works correctly. If something "doesn't" work, then fix it. In this case, the system works fine.
          I've never seen a problem or heard of a front cam bearing problem.



          • #6
            Right. I wasn't sure if there were front cam bearings with two holes for different years or if it was a "improvment" to add a hole. I'll leave it alone. I do enjoy reading the engine manual but sometimes I dig to deep. 😬


            • #7
              The lowest oil pressure point in the entire system is the #1/#2 rod bearing
              (farthest point away from the pump).
              The feed point for that is the front main bearing.
              The feed point for that is the front cam bearing.
              I would be real, real careful about doing anything that could/would/should change the pressure/flow in that feed setup.
              Some testing would be advised.
              HTIH (Hope The Info Helps)


              Get your facts first, and then you can distort them as much as you please. Mark Twain

              Note: SDC# 070190 (and earlier...)


              • #8
                Haven't looked at the oil passage info in the owner manual but is the second hole to oil rods and mains or to oil both sides of the lifters? Buick v-6's oil the lifter though a hole on each side of the front cam bearing to each side.


                • #9
                  I tend to agree with Jeff and Mike as to leave well enough alone. The only bearings I ever drilled out (a lot) were mains on big block Oldsmobiles. This was to align the oil holes in the bearings much better to the holes in the block. But I emphasize that I was advised to do this by none other than Joe Mondello (Dr. Oldsmobile) and I think he was the ultimate Olds engine guru on the planet.
                  RIP Joe


                  • #10
                    It it works with competition engines in stock form, and it does...