what effect does a reground cam have on the crank timing, if any. and if there are any what adjustments do you make when installing a ported and polished head with the cam reground?

 

usually regrounds get their base circle ground away to increase duration, though the power is nice it usually leads to premature rocker arm and or valve failure of some sort because the velocity in which the rocker arm goes up and down is increased like mad. Im not sure how long it takes on a honda, I went about 6-9 thousand miles with mine and didn't have any problems, i plan to go back to it but not right now. ohh and no affects on the timing and no adjustments when installing the head, just the standard valve adjustment