MP DISTRIBUTOR TIMING CURVE 340
I'm trying to wrap my head around how changing the amount of mechanical advance changes the initial spring tension...?
That's why its best to do it and observe the mechanical relationships.
Without digging into my notes, etc., with the YH advance when the top plate moves relative to the one below, it also moved the weight pivot relative to the spring perch.
What I really think about the design is exactly what Tuner wrote. But if that's what someone has, thats what they have to work with.
I graphed an example in that thread quoted above. This one
Distributor springs
So
IF this is a Mallory YH advance
@CFD244 may actually find is that increasing the degrees of advance allowed may actually delay the start to an even higher rpm. I've edited my earlier to reflect that is probably the relationship. This is where observing on the bench is really worthwhile. If you want to get fancy you can put a 360 degree 'wheel' underneath and place a pointer on the distributor top shaft. Buts its not neccessary just to see what is going on. What
@CFD244 might also find is the 14* setting was stopping the advance before the secondary spring did anything. No way to know what is in there and how far out or in the perches are bent until one looks. Sorry about not being more specific, but its been over 5 years since I've messed with Mallory stuff and I just don't recall the details off the top of my head anymore.