adjusting advance curve on the vacuum advance distributor

[Arns85GT]

How do I adjust the advance on my vacuum advance distributor for the 2.8?

I have an 86 carbureted type distributor and someone told me that the advance is adjustable for optimum power curve.

Does anybody know how this is done and a good source to read up on the theory?

Arn

[RacerX11]

The stock vacuum advance canisters are not adjustable for rate. You would need to install an aftermarket adjustabe one (try Summit or Jegs). They are adjusted by putting a small allen wrench into the vacuum port, and turning the screw that sets the spring preload on the diaphgram.

You can adjust the stock unit's position (some have slotted mounting screws), but this only shifts your timing, it doesn't change the total amount or rate of the vacuum advance. The same thing can be accomplished by adjusting the base distributor timing.

Marty

[Arns85GT]

Thanks, Mine is slotted and it is very handy to know that they adjust the timing. I don't think I have an allen head in the vacuum port. The port is only 1/8" and I can't see down inside. I'll try sticking an allen or two down the hole and seeing if I encounter anything (of course easy does it)

I'll check for the item on the websites. Thanks for the lead