Got the new Carbs on, and a question.

Well, last week.. the rebuilt Dizzy went on, and today I put on the new set of rebuilt carbs and the new intake manifold I bought from Tom Arrigo (my73B ).



After priming the bowels with the fuel pump, I opened the choke and gave it a shot. A few seconds later she fired right up. It needs some adjustments and I still need to adjust the timing on the new distributor, but I am happy with both that it started and the nice clean look. Too bad the engine bay doesn't match the new parts. :(

Anyway. What is this for on the rear Carb?



Is it another place to run the line to the vacuum advance, as I have it hooked to the manifold like I did before. If it is not necessary, I guess I could just get a cap to cap it off?

Thanks

Paul

Yes, it's a port for the vacuum advance. From what I understand it's more desirable to run it off the rear SU. But it's possible Jeff set up your dist to run off manifold vacuum. I dunno! Either way, you gotta plug one or you'll have a major leak.

Jeff is the expert, but whether you should use the carb's vacuum port or directly off the manifold depends on your vacuum advance unit. If I recall correctly, the carb port does NOT give vacuum at idle whereas the manifold obviously does. Your distributor (centrifugal and vacuum) advances need to match the port you are using.

Thanks.

I believe Jeff set it up to the manifold for the advance. I will wait for him to chime in or I will send him a PM.

Paul

I have the same thing that sticks out and didnt know it needed to be plugged for quite some time. I just stuck a little black rubber cap over it that I picked up from Home Depot.

ASK.

It is important.

in any event, the unused vac advance port must be plugged. Not left open.

It looks like you have a couple of open ports on your intake manifold that are nothing but a vacuum leak.

ekafant Wrote:

Your distributor is set up to run off of manifold vacuum, but it may work well on either. You may want to try both to see the differences for yourself! You will be able to advance the timing a bit more when using the ported vacuum!

ome models (very early IIRC) took distributor advance from here in lieu of from the manifold. Vac here is probably less than from the manifold, so if your dizzy operates properly from the manifold, plug this one.