HEI advance info
Originally Posted by TNCHEVYMAN
Help, I just got a hei from whites perf. for my sbc 355. A great deal! I wonder about the curve. it,s got the 65k coil,and other mods but does it have a performance spark curve. it has the adjustable vacume adv. What do i look for to set the optimal curve. I read some old posts about the subject. I am going to set the timing at 3000 rpm. then turn it back to stop detonation. after that what am i looking for. what should timing ge at 3000. THANKS I love the info i get at this site. Its the greatest!
has some info about timing and the advance curve, etc.
Basically the more cam you have the more initial advance you'll need. The more initial you need means you need less
mechanical advance to keep the total advance from being too high. Too much total advance can kill an engine w/detonation.
MSD uses bushings to limit the mechanical advance. But stock GM HEI and some aftermarket distributors (like yours IIRC) have to use other more involved ways to limit the mechanical advance.
But like TI said, all the details need to be considered in the mix to come up w/some numbers.