adjusting vacuum advance

[wireweld]

I have a Mallory Series 32 dizzy with vacuum advance. What does the adjustment screw in the pod do? Does it adjust the advance or how much vacuum is needed?
Also I will be running 16 degrees initial with 34 total. How do I set the vacuum advance, or is that what the screw is for?
I am a newbie at this stuff so be easy on me.
Thank you.

 

[mopar340dave]

The adjustment limits or increases the travel of the canister as in the amount of vac advance. The vacuum source needs to be ported as in no vacuum at idle.

I would cap it and set your initial and see what you have when and then hook it up and adjust from there.

 

[dgc333]

Unless the Mallory vacuum pod is completely different than the factory pod the adjustment screw adjusts the preload on the spring that returns the pod to the zero advance position. The net result is you are adjusting the amount of vacuum required to make the advance start to move and the total amount of vacuum required for full advance. The amount of advance the pod can provide is built into the mechanical stops and is not adjustable.

Once you get your initial and total set take the car out for a drive with a vacuum gauge connected to the intake. Find the vacuum level you get while crusing on level road with no head wind at approximately 40 mph. You want adjust your advance to have full stroke at this vacuum level. I use a mighty vac hand vacuum pump for this. Now take it for a drive with the vacuum advance hooked up. As long as you don't have any detonation issues you are good to go. If you do then you will need to back off the advance some.