Vacuum advance on this Holley R80069

[1930]

Not sure what the original carb number was but Im pointing to the vacuum port that went to the advance on my dist. This new carb that Ive installed has a port there but its much smaller and I cant necessarily feel any vacuum putting my fingers over it.

Can someone tell me where I should be getting what I need from this new carb?

Thanks

 

[yellow rose]

Hook the vacuum advance to a port ABOVE the throttle plates. You don't want manifold vacuum on the VA.

So hook it to whatever port does not have vacuum at idle.

 

[nm9stheham]

If that is the right port, it won't have any vacuum on it at idle. It only produces vacuum when the throttle is open under load; i.e., while driving. It is called ported vaccum.

 

[Rapid Robert]

If that is the right port, it won't have any vacuum on it at idle. It only produces vacuum when the throttle is open under load; i.e., while driving. It is called ported vaccum.

I'm thinking that side port is for some other vac system (not sure). First I would see if there is another port on the base that is ported (no vac at idle) to use for the can

 

[1930]

Hook the vacuum advance to a port ABOVE the throttle plates. You don't want manifold vacuum on the VA.

So hook it to whatever port does not have vacuum at idle.

I see, just now figured out what I needed to understand, if I hooked it up to a port below throttle plates than I would have vacuum at idle ( which only makes sense ) and of course I do not want this.

Thanks, this was a big help for me.

Can you tell me how I would test a port above throttle plates to see if that port produces enough vacuum to move the diaphragm?

 

[1930]

If that is the right port, it won't have any vacuum on it at idle. It only produces vacuum when the throttle is open under load; i.e., while driving. It is called ported vaccum.

I'm thinking that side port is for some other vac system (not sure). First I would see if there is another port on the base that is ported (no vac at idle) to use for the can

I understand, see my post above about testing these ports to determine which would produce sufficient vacuum. Thanks again