Tuning For Detonation
Or the old school way.
Weld up the inside of the slots once you know what the curve looks like.
(Full description in this post)
What that does.
Lets say this was a distributor from a '69 225 ( I know its not, but it happens to be one I have specs for).
And the timing measured when initial set to 0* initial looks like this.
Lets say we want 32* by 4000 rpm, not 28*.
So turn this distributor to so the initial is at 4*BTC.
But with this engine we know its going to need more initial to idle decent.
Weld the inside of the slots and timing looks like this
That should have no problem working with the original vacuum advance.
To get the timing to advance sooner above idle rpm, turn the spring perch so there is the least tension on it.
To bring the long spring into play at a higher rpm, turn its spring perch so there is more slop.
OK. But does it have to be 20? Does it generate half decent manifold vac at anything less?
and every 200 or 250 rpm from as slow as I can get it up to 2250 or 2500.
That would definately be a clue for what curve looked like.
See what Ray has in the bin he could send you, along with some springs.
Or the old school way.
Weld up the inside of the slots once you know what the curve looks like.
(Full description in this post)
What that does.
Lets say this was a distributor from a '69 225 ( I know its not, but it happens to be one I have specs for).
And the timing measured when initial set to 0* initial looks like this.
Lets say we want 32* by 4000 rpm, not 28*.
So turn this distributor to so the initial is at 4*BTC.
But with this engine we know its going to need more initial to idle decent.
Weld the inside of the slots and timing looks like this
That should have no problem working with the original vacuum advance.
To get the timing to advance sooner above idle rpm, turn the spring perch so there is the least tension on it.
To bring the long spring into play at a higher rpm, turn its spring perch so there is more slop.
