[Sun Tuned]

Head#96,
Not really any damaging effects from the dist advancing too soon. I mean that the motor won't be condemned by it and scatter pieces all over the neighbors yard. Performance, will be hampered. How much? Depends on how bad off it is. The main thing that you'll have a problem with is trying to set the mixture and idle speed on the thing, if the advance starts too early. No consistency in the mixture screws, idle speed, or both. The rest of the tuning parameters are affected by this.

Most guys that set up their distributors and even some of the so called "pros" will get so worked up over trying to get the thing "in by" a specific number rpm. That's a novel idea and really what your trying to do, but alot of people pro/nonpro severely blow it when it comes to the question I always like to ask...."Yes, but where does it start??" See, the springs that are commercially available are just as much to blame for this as anything. Most suck. You get into a situation where you jack with the thing long enough to get the curve in by say 3800, but the thing starts at 1200. Then you change up a spring or two and now the thing comes in by 3000, but now the blasted thing starts way down low like say 450. Scrap all that and try the 2 lightest springs most of these kits come with and now it starts at 450 and now it's in by 2000. ??????? You end up wanting to take a hammer and beat the whole damn car into some very small pieces, or you have to settle for what you get. Well, that is the exact reason I spent alot of time 5 mins across town worrying the blue hell out of the man what runs a spring company here. I have him make mine. Matched to the job I'm doing with them, not thrown in a box like 99% of these aftermarket kits as an afterthought. Sure they cost like hell cause I'm not buying them 4 million at a time and my last name isn't Hrudka, but they work for me. You can tweak some of these aftermarket springs. Bend on em, stretch em, etc. The main thing is to watch where the curve starts... just as important as where it ends in my opinion.

I think the spring, in my opinion, needs to be as stiff as possible. WHAT! Thats right, stiff. See the way I see it the stiffer the better, as long as the spring allows you to reach the selected range your trying to run your curve in. You will have less timing problems due to spring fatigue that way. These light hair thin jobs look cool but they woefully suck after a few good heat cycles, changing the curve specs from what they were originally set up for. People distributor springs around here get just as much attention as a set of valvesprings. Why not they are just as important. You want a spring that positively holds the weights on that advance cam lobe at idle in one spot and only in that spot till they are supposed to move from that spot. Then they need to allow the weights to follow the curvature of that cam lobe just as closely as you want the lifters in the valvetrain to follow the camshaft lobe itself. And just as sure as a set of cheap lightweight valvesprings will allow valvetrain problems, will a set of hair thin distributor springs cause an ignition problem. Without enough tension the weights will not return accurately to the at rest spot when needed either.

You really wanted the short version now...didn't you.