Hi, I have a 6 Barrel carb setup (on a 440), and I just replaced the diaphragms. I connected the two outboard carbs and performed a (static) suck test with full throttle on the center carb and both carb butterflies open. The problem I am having is when I connect the two outboard carbs to the upper vacuum port of the center carb metering block the outboard carb butterflies don't actuate. I'm getting above 20hg on the metering block with the carbs disconnected when I connect either one I get 0 vacuum on acceleration. Just for kicks I connected the the outboard carbs to the manifold vacuum and the butterflies actuate on acceleration. Any ideas would be appreciated for a Mopar newbie

...also worth noting...the outboards never worked since I purchased the car recently...I noticed the diaphragms were torn.

 

If you google "dodge six pak vacuum connections. In the images, you will see the lower vacuum port on the center carb is the outboard carb connection and the upper port is the metered vacuum for the distributor vacuum advance.

 

The lower port was connected to the advance already, I noticed it has no vacuum at all...I assumed it was blocked off. Curious

 

Does anybody know any reasons why the lower outboard carb feed port has no vacuum?

 

You'll have to take it apart and check the passage!

 

I blew some air through the port and it appears to be clear, I also spoke to Holley support and he said that if it isn't blocked then you probably have a fuel leak on the center carb which is effecting the venturi vacuum. Looks like a rebuild kit is on order

Thanks for your feedback, much appreciated.

 

Does anyone know what rebuild kit I could use here, I was also wanting to include the outboard carbs in the rebuild as well.

 

You will have little to NO vacuum at idle on this port. Put a gauge on it and rev it up to check it, or just hook up the outboard vacuum line to it and test it (full pull somewhere safe) for actuating the outboard carbs. Sometimes the outboard carbs need the kill bleeds resized (smaller) to get early actuation! I wouldn't go to a rebuild kit just yet!

 

Yes, I did put a vacuum gauge on this port with no vacuum at any rev.

 

It may only have the wrong metering block gasket, or it's possible the gasket may be installed backwards. You can check the passage with a piece of fine wire(unwind a piece of multistrand copper wire and use a single strand) and not require any gaskets. You should be able to see the wire come into the throat of the carb. I think (memory) into the booster nozzle.

 

Here are the links to the best 6pak information I have ever found.
http://www.mopar1.us/carbs1.jpg
http://www.mopar1.us/carbs2.jpg
http://www.mopar1.us/carbs3.jpg
http://www.mopar1.us/carbs4.jpg
http://www.mopar1.us/carbs5.jpg
http://www.mopar1.us/carbs6.jpg
http://www.mopar1.us/carbs7.jpg

Everything you always wanted to know about the Dodge six pak but were afraid to ask

 

Thanks Drag Pak, good reading. Most people don't want to hear this but I temporarily converted the linkage to mechanical, until I get this sorted.