What is your interpretation of these advance springs?
Like hoppy said, those are some sort of factory springs.
The one with tension on it is the primary spring and the one with the long loop is the secondary spring.
The factory used different combos of primary and secondary springs for almost every year and variation in engine and transmission.
The numbers on that sheet are most likely distributor degrees and distributor rpms. But not everyone does it that way. That's the logical way to do it if you are working on a distributor machine and how the FSM specs the mechanical advance. To convert to crank degrees and rpm, double the numbers. So my guess the last line means 34 crank degrees at 2000 rpm for the camshaft and distributor. Easier to understand as 34* maximum advance at 4000 rpm. This is not total as most people use the term. Total is initial plus maxiumum mechanical advance.
I don't have much slant six stuff plotted but here's two sets of specs from the '68 Plymouth Service Manual.
A 70s distributor will have a curve closer to the CAP advance specs.
Like hoppy said, those are some sort of factory springs.
The one with tension on it is the primary spring and the one with the long loop is the secondary spring.
The factory used different combos of primary and secondary springs for almost every year and variation in engine and transmission.
The numbers on that sheet are most likely distributor degrees and distributor rpms. But not everyone does it that way. That's the logical way to do it if you are working on a distributor machine and how the FSM specs the mechanical advance. To convert to crank degrees and rpm, double the numbers. So my guess the last line means 34 crank degrees at 2000 rpm for the camshaft and distributor. Easier to understand as 34* maximum advance at 4000 rpm. This is not total as most people use the term. Total is initial plus maxiumum mechanical advance.
I don't have much slant six stuff plotted but here's two sets of specs from the '68 Plymouth Service Manual.
A 70s distributor will have a curve closer to the CAP advance specs.
