There are a few online spring rate calculators around, they work for tiny springs as well as car springs. All you need is a good set of verniers to get the wire thickness.

http://www.pontiacracing.net/js_coil_spring_rate.htm

With 10deg initial advance at idle, you should go out to 35deg at 3000rpm. just mark the pulley with a white pen out to 45deg.

Look out for having too little spring strength as the arms may be halfway out at idle and you only get 20-25deg advance at 3000.  All this work is done with no vac advance attached.

 

 

I tried the new springs and the marker on the pulley keeps rotating towards 0° when i rev the motor but it feels a little better than what it was, should i still have vacuum advance line hooked up or not?

 

when u are revving it, the manifold advance changes very little, unless there is load on the engine; then the vaccum and therfore the advance diaphragm dies off.
what happens to the timing mark  if u leave the engine at idle, and unplug the hose from the diaphragm? (whille immediately capping the hose with ur finger so u don't get a massive vacuum leak).

Sayign that the centrifugal weights should be advancing.
SO the onyl scenario in my mind that can possibly cause a retard on revving, is if the weights are sezied, and the manifold vacuum is dropping off as u stab the throttle. any other gentle revving the manifold vacuumm really doesnt change enough to effect the advance diaphragm.

Edited April 26, 20188 yr by rebuilder86

Can you take a photo or two??  Did the weights rotate the shaft when you pulled them out??

At idle the timing mark should start at 10deg to the left (anti-clockwise) of the zero deg, TDC, on the timing cover.

As you rev it the timing mark should move further anti-clockwise, out past 20deg.

This photo is set up with timing at 10deg BTDC, it will have the pulley marks move downwards (anti-clockwise) as it is revved. I had the daughter watch the tacho and hold the revs at every 500revs while I held the timing light on it.

All this timing is done with the vac hose off & blocked, as Rebuilder said, we are just measuring the effect of the weights.