Missing Carb Ports

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Jul 17, 2008 | 10:45 PM

yukgoon

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From: Savannah, GA

Missing Carb Ports

I recently bought what was labeled as a Holley 0-8007 390 CFM rebuilt 4bbl. I went on Holley's website to get the instructions about it and it seems like my carb is missing some ports. IE the vacuum advance port and the PCV port. For the distributer advance port I think I can just go and buy a screw in adapter for the port but I cannot seem to figure out where to attach the PCV hose. Can someone send me pics of your carbs on the side of the choke so I can figure out where this PCV port is supposed to be. I searched the galleries and I found some pics but they do not seem to look the same.

Jul 18, 2008 | 08:24 AM

fmc400

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Joined: Apr 2004

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From: Austin, TX

Any place that you can get manifold vacuum is acceptable for the PCV valve. Most often it takes a 3/8" vacuum line. I am running an Edelbrock which already has a 3/8" port for the PCV line, but I needed another 3/8" manifold vacuum fitting for my power brakes. My manifold had a threaded port, so I installed a 3/8" beaded hose barb there and attached the vacuum line. You can see it in the picture below, it's right under the carburetor on the passenger side. The point is, you need to connect the PCV valve to manifold vacuum and most intake manifold have threaded ports where you can install vacuum trees and hose barbs for whatever you need.

Jul 18, 2008 | 08:27 AM

manglass

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Didn't read your whole post the first time, never mind.....

Lou

Jul 18, 2008 | 12:18 PM

Harte3

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From: Spokane, WA

Which manifold do you have? The Offy has two ports drilled and tapped. I don't think the Clifford has any...may require some adapting and improvising.

I haven't heard of that problem with a 390 before now. There are race versions of the 390 that might not have all the ports. A model 1848 465 cfm I ran for a while only had one small port on the body of the carb...apparently a venturi sourced timed port for the dizzy so I used the ports on the manifold for the brake booster, PCV, and dizzy.

http://i144.photobucket.com/albums/r194/Harte3/001.jpg

Jul 18, 2008 | 12:29 PM

yukgoon

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From: Savannah, GA

I have the clifford 6=8 manifold. It is all single port. I am not sure what the deal is with my carb if it truly is a 8007 or not. I would post a picture but have not figured out how to on these posts. I should be able to find a fitting for the distributer vacuum advance but can all the PCV and power brakes just come off a fitting on the manifold instead of the carb?

Jul 18, 2008 | 01:07 PM

fmc400

MSEE

Joined: Apr 2004

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From: Austin, TX

Quote:

Originally Posted by yukgoon

can all the PCV and power brakes just come off a fitting on the manifold instead of the carb?

Didn't you read my post?

Jul 18, 2008 | 01:48 PM

Harte3

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Joined: Dec 2006

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From: Spokane, WA

With the Clifford you will probably have to drill and tap holes in the manifold for the vac fittings you need. A machine shop can do that for you too.

Also, look at the carb, write down all the numbers you find and send them to Holley Tech Service accessed from their web site and ask them about the carb and vac sources or call them. Post those numbers here too...someone with a 390 may be able to help.

http://www.holley.com/data/Products/...199R8108-2.pdf The photo in Figure 4 on that page shows three vac ports for a 4160 model carb. BUT, there are variations within the model series.