Distributor springs

canyncarvr said
I have a Mopar distributor that uses Mallory's YT advance. The Mallory spring kit comes with springs ranging from pink (6lb.) to orange (13lb.) Mallory's timing curves show that two orange springs (the heaviest) will max out at 2500rpm with a 20º limit in the distributor.

The weights are my numbers, measured via scale with the springs at 3/4".

I want to raise that rpm, getting 18º at 32-3400rpm.

Other brands of springs should work, but it would be helpful to know what the options are.

Does anyone know the pull/tension of other brands of springs? MSD maybe? I can double a spring, but I'd rather not. I can reduce the weight value, but I'd rather not fuss with that either. I am looking for the simplest approach, and a 'correct' (for my intended use) spring is exactly that. Springs in the upper teen range would be great...if I can get them.

Thanks for posting the spring force at 0.75"
The MP version of the kit had spring rates posted on the back cover.
I compared by measuring the diameter of the wire, the coils and counting coils to calculate rates. Most were close.

I'll look at my spreadsheet after dinner and see if any other springs, such as the Crane kit for GM points is in the same range.
The YT, YH advance is a PIA design to do what you want. I was trying for something similar and was moderately succesful using heavier springs and bending loops and/or spring pivots.

It came up a few times in this thread with some pictures of springs and weights (skim through you'll see a little on page 1, then bottom page 2 into 3).
Too much advance at light throttle?

and a discussion about modifying the weights in this thread.
Modifying YH Advance Weights
Which I haven't got around to trrying myself yet.