I'll see if I can clarify.
The other way. That's the analytics with an example that was handy for me to upload. LOL.

Seriously. For the purpose of showing the effect on the timing, yes that is what this first graph with the black line shows.

We could just look at it as advance. That's often harder for people to picture how that effects the timing curve.
This example is about changing the advance so more initial timing can be used without changing the middle and top end timing.

The next graphs were illustrating how the curve would shift if the initial timing desired (12*) was set at 700rpm.



There is no equations here at all. Those are the timing and advance specifications from the 1968 Plymouth Service Manual. Anything within those lines would have been acceptable. I'm assuming the top or maximum timing for the examples where I sketch in the result of a change. Its not the real curve. Its just four points connected so its easier to see.


That's interesting. I thought I'd seen some variation in distance from collar with the Chrysler cams, but not much. I don't have any points cams to check. Am verious as to the pre-68 non-CAP vs the later ones for the same engines.
One thing certainly seen is angling of the slots in some of the longer advances.


Yes.I agree. If you have a selection of springs, or can wind your own, then it doesn't matter. But the heavy long looped spring, which can be really important, is really difficult to find if you don't have a collection already. So that's why for most folks, the inside is easier approach.

Now you lost me here. LOL. If you're describing the arc of the weights, and the changing angle of the spring, the design is pretty good because it helps to compensate for the centripital force. Some of the aftermarket designs really fail to do that.