I am looking for any suggestions when it comes to running Weber carbs on a common plenum intake. I have seen some pictures of the cb performance sbc intake manifolds. They ran 2 Weber carbs down the middle vs individual runners with 4 carbs like most traditional v8 Weber manifolds. I found an old picture and the caption mentioned two IDF40 carbs. I am looking at building a log style intake manifold for a small v8. (281ci). the engine is basically stock and used for cruising. I am trying to figure out if this is possible to do and which Weber carb would be the best for this. That's if it can even be done. any help is appreciated. I have searched for a couple days but info on common plenum setups is tough to come by.
I would build that manifold so that each barrel serves no more than two cylinders, if using IDF's If you want a single log, you would need to weld bulkheads in it.
i had considered doing 2 cylinders per barrel or a bulkhead log. my only concern is the firing order. 1-3-7-2-6-5-4-8 is the firing order and 2 and 6 are across from one another. So would I have issues with the fact that those cylinders are right after one another? From some reading i found most guys suggested trying to run opposing cylinders. Im just not sure about trying to pair 1-6, 3-5, 7-4, 2-8 in regards to tubing. And any thoughts on size of carbs?
Log manifolds are never all that efficient. You might be able to smooth this out by drilling a hole in each bulkhead, to allow a little flow into the next sub-plenum. I might use two 32/36's, on a open log. A 32/36 is an inline progressive 2-barrel, and they work pretty well. Might look pretty cool, too. You can get a plate so that you can put a common 5-1/8" air cleaner on a 32/36. THis gets you into any number of possibilities. You might even be able to fine a slick dual-quad air cleaner, for extra style.
yeah, I guess its not a big deal, but being a traditional site i wasn't going to go announcing its going on a 4.6L Ford. But hey, I got it for free and it will be different. Its a 2v engine so I have a 2 bolt front mount Flathead distributor coming in. a friend that is a machinist is going to help me extend the driver timing cover up and then front mount the distributor. We will drive it off the cam sprocket bolt. The valve cover will be cut out to clear the timing cover modification. I also sold the 4r70w that came with it and got a big bellhousing c4 bolted on it. I could just buy an edelbrock 4 barrel intake but that just takes the fun out of it.
I think going the unusual route with the intake and carbs sounds like a good idea. People would be scratching their heads, for sure.
As you probably know, the best way to set up the Weber carbs is to have one port for one intake runner. Unless you are doing it for looks, you are wasting the advantage of running the Webers, and you might just as well run a 4 barrel. I have seen adapters that mount two DCOE Webers on a standard 4 barrel manifold, and if you are just doing the conversion for looks, that might be the least expensive way to go. We built a system for my son on a Chevy, and have 4 Weber DCOE on a Moon manifold. For the vacuum advance, I built a vacuum supply chamber out of a 6 inch piece of copper pipe, and drilled the bottom of each port and ran the 8 lines to the pipe. It sounds complicated, but it is easy to put together. Another way to install the vacuum lines from each intake port, would be to make 4 spacers, for the two carbs, and drill the spacers for the installation of the vacuum lines. Good luck on your installation, Bob
How about three Webers, so you feed each intake runner with one port? The carbs in the photo (found on the interweb) are DCNF 42:s.
This is the setup I was thinking about replicating. Im just not having much luck on what carbs to use or if this is just a horrible idea. Another part of me says to just use a couple holley 94 but I just thought this looked different. This project is not a race car. I want it to be streetable but im not tying to race it or anything.
I have one of these CB Performance intakes. Supposedly 1 of 7 made is what I have been told. I have not used it yet, but its planned for an open Model A.
2 Weber IDF 40's. I will keep you posted, but I am still a few months off from getting to that point. The manifold in your picture above is the one I own. I bought it a couple of years ago from a guy here on the HAMB.
In '68 or 9 Ford actually made carbs like that and used both one and two 4-throat carbs on a cross ram manifold. They called it a Cross Boss. You just drill a blank intake cover as needed.
I bought a Holman-Moody 289 in 1968 that came with a cross ram intake that had a removeable top that had 3 tops. One for dual quads, one for single 4 barrel and one for webers. I used the dual quads and the single carb , but never used the weber top. I wonder what that intake is worth today with all 3 tops?
There's also an intake for the 427 cammer that holds 2 of those autolite inline 4 carbs.... Check out the engine picture thread.....
Hello, I have this same intake myself. Do you have any info on it? This is the only post/pic I've found all the way to the end of Google.
This is pretty much all I know. They were built by CB Performance, and there were only 7 made. I guess they didn't go over that well, so they were discontinued.
You could use almost any aluminum donor manifold , mill it flat on top, & weld on a 3/8" aluminum plate. Then layout & drill for the mounting bolt & venture holes in any arrangement you wanted(especially in that sideways 2 x2 in post #10 above!). it'd be "clean", simple, INEXPENSIVE( especially when compared to the one in #10!), &, best of all, you did it yourself!!
I have 32/36 Weber’s on both of my A’s and just swapped out some Solex carbs on my Jag for 32/36 Weber’s
i always thought you had to orientate them specifically dcnf - transverse mounted idf front to back something about float bowls and surge
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