[Johnny406]

I'm trying to get a better understanding/grasp of this bearing modification.

See picture, on a unmodified bearing, the oil hole is dead center and aligned with the camshaft lube hole. On the crudely modified bearing, I drilled a larger hole to represent the modification with a bit approximately the size of the actual oil passage inlet hole where the hole aligns with the block.

Question #1: Would doing this modification, with more oil flow and less restriction at the mains, be a de-facto oil restriction for the top end/valvetrain? Will this hurt HFT cam engines?

Question #2: Will I need to shim the pump spring to slightly raise the pressure to compensage for the pressure drop at the mains?

Question #3: With more oil circulating on the bottom end, will it all get back to the pan in time so the pump doesn't cavitate?

Question #4: On the front main, should I just enlarge the center hole?

Question #5: Any negative effects from doing this modification?

If I do this mod, I will certainly buy new/sharp drillbits and use my press. This bit in a hand drill sucked...