Holley 2245 2bbl in '79 'doba

[ybshore]

In trying to clean up another's poor attempt at abandoning LB on my '79, the conclusion we are coming to after cleaning up the electrical's -we think- in regards to vacuum issues, is on the ported Holley what port would be used for vacuum advance?

 

[WileE]

Use full manifold vacuum.

 

[ybshore]

From where -presume same spot where power brake booster is connected- and then to which port on a Holley 2245?

Use full manifold vacuum.

 

[Jonnyuma]

Full manifold vacuum is highest at idle, when the throttle blades are closed. Connecting to manifold vacuum will have your vacuum advance distributor advancing at idle and retarding when you open up the throttle and reduce vacuum. Basically the exact opposite of what its supposed to to. Full manifold vacuum is where you want to attach a gauge and measure vacuum. Ported vacuum (before the throttle blades) is where vacuum is least during idle, and most during higher rpm situations. That's what will advance your timing properly.
I've heard of people connecting thier vac adv distributor to mani vacuum, but I've never heard a theory on why they would do that. Maybe WileERobbie could explain the physics behind that....?

 

[RWG75]

If you have a non ELB 2245 there will be a port on the front of the throttle plate next to the PCV port. It connects to the main venturi just above the throttles and only gets vacum when the plates open. If the carb you have is the original to the ELB setup, it wont have this port.