I have a Swift Tune SW5 cam in my 1275 and the timing tag that came with it said the lash should be set at .015". My question is: Since Swift Tune says the cam is ideal for 1.5 rockers, is the lash setting the same or should it be opened proportionately over the 1.3 ratio rockers? I calculated that to be .017". Surely there must be a lot of people running this combination. Which do you use?
Also, when I adjust the valves by the rule of nine I get one rocker that taps noticeably louder over the others. This is a newly built motor with less than 6K miles on it. While trying to adjust this tapping valve (#1 exhaust) I discovered that the clearance would vary while rotating the crankshaft as if the base circle of the lobe was not even. If I adjusted the lash with the cam just coming off the lobe I would measure .020" whereas rotating it to the position with the #8 rocker fully open it measured at .015". I used to own a BMW R65 motorcycle that did the same thing and I never could figure out why. The base circle should give a constant measurement at all positions off the lobe. If I set it at the spot with the widest clearance the motor quiets down. Will it hurt anything to drive with the valves set this way? Any ideas or experiences? Thanks!