Dual point distributor ID question

mvh said
1. Stiffer spring = advance comes in more slowly (seems obvious). No idea where you would get a replacement spring.
2. The limiter — not sure what this is, or how you would adjust it
3. The washers — more washers = what? Advance comes in faster, or slower? My impression was that this was the only user adjustment

There were tune kits in the past look on eBay for nos kits.

In the Ford version at least there was a plastic tube inside the spring. Shoerte allows more vac advance longer less.

A coil spring as a particular spring rate lbs per inch. It is basically linear.

If a spring has a rate of 5 lbs per inch the diagram will move 1 inch with 5 lbs of suction, 2 inches with 10 lbs. ( These numbers are just numbers for illustration)

Now you take the same 5 lbs per inch spring and compress it 1 inch (preload)
Now it will take 10 lbs to move it the first inch. The washers do not change the spring rate they just set the ride height so to speak.

So for tuning purposes. If you want your vac advance to start later add washers.

If you want it sooner remove washers.

If you want it to advance quicker, lighter weight spring, slower heavier spring.

I haven't had a distributer Ford in decades. But I still have these parts.

Note the similarities

FYI

The adjustment in the vac canisters that can not be opened. Only sets the vacume at which the can starts moving. The same as adding washers.

The spring rate stays the same.