I have always heard what was mentioned earlier in this thread about a single 4 barrel making more power than dual quads. Ok, I just accepted it figuring guys smarter than me had found this out on the dyno or drag strip. But, why does a single carb make more power? I don’t know the answer, and I’m not trying to be a wise guy, just genuinely want to know.
The key word I was using was "modern" carb/manifold as opposed to the older '50's-'60's dual 4's. I believe the single 4 carb/manifold from back in the day did not have the power the dual 4's from same era had. Lot depends on the "build" specs of motor underneath also. I had a FI '62 corvette for 15 years, somewhere along the line I took off the FI and installed a Team G and a Torquer with a 780 Double Pumper, torque & power gain was very noticeable. Apples & Oranges some will say.....................
The OEM dual 4-bbls and most early aftermarket aluminum 2x4-bbls were no taller than the single 4-bbl OEM intakes of the era. The low-rise design first priority was "fit under the hood", and second was to be a dual plane for good idle. Today's high rise single-plane single-4-bbls which make more power often won't fit under the hood and because they're single plane, don't idle well, especially with some cam. But today's tunnel ram 2x4-bbls make a lot more power than the best single 4-bbl. It's all about plenum size, runner length and size. jack vines
Since I run them and have for years it’s the “look” factor especially on a YBlock Ford. I’m not taking bling because the only part that’s aluminum is the intake manifold and there are no chrome parts on the originals. What’s under the Purolator air filter.
i've got a pair of carter competition 500's here. I'm struggling with fuel lines and getting the throttle cable to work with them. I'm sure i will figure it out eventually... Not a lot of room under the hood of a Model A with all this in it though. View attachment 5964624
Do you have a picture of your front belt setup for that? Ive always wanted to stick a 4-71 on the small block in my 33 pickup, but that was always the hangup was the front belts pushing to forward causing alot of firewall recessing I don't want to do.
Looking for rebuildable or ready to go WCFB 4 barrel carbs, 2 of same. Must fit a SBC Eddy C-26, as in my first post pic top of 1st. page in this thread. Willing to spend 4-6 hun, depending on what they are. If needing rebuild not interested in any carb I can't buy rebuild parts for. Thanks!
Your best bet are 57-61 Chevrolets. They are the most prevalent and so close to being the same no one can tell and the stock dual quad linkage works perfect. Many are buying them up and doing fake original DQ units but the revised choke on the front one gives it away. You may need to buy 3-4 for parts to do it. Good luck.
This is the Offy dual quad intake with Edelbrock 1405's in my '34. The carb bases on this intake are much further apart than on your E intake, so I had lots of room, but it put the rear carb very close to the distributor. It also ran way to lean at idle so the front (secondary) carb had to have the idle jets opened up in order to run right. The progressive linkage worked very well, the engine was a screamer. I didn't get inside it, it was alleged to have a 327/350 horse cam, it had double hump heads and had, again allegedly, 10.5/1 compression. Great little engine.
The original engine in my 57 had two four-barrel carbs on it. They were WCFBs. When I got it, the engine was beyond help, so I got another 318, built that and added the two fours. It ran well and even better after adding an Isky cam and Hedman headers.
I haven't accepted the statement to always be true! There is no doubt that many modern designed intake manifolds are more efficient than most intake manifolds from the 1950's and somewhat more efficient than some intakes from the 1960's. PackardV8 mentioned part of the differences with whether the unit will fit under the hood. Dual quads of the same height or even close to the same height often are more efficient than the single quad due to more even cylinder fill density. And each engine will be different. And the ability of the individual selecting and tuning the setup, whether dual or single is a consideration. Be careful believing magazine dyno tests. Magazines have advertisers; advertisers products should perform well in all articles or tests. Magazine tests can be akin to surveys: "What is the individual directing the survey wishing to prove?". Example: a few decades ago, one carburetor manufacturer did not offer a 600 CFM carburetor. Did the Board of Directors instruct the engineering department to design a 600 CFM carburetor? They did not. Instead, they renumbered a 625 CFM carburetor and advertised it as a 600. If a magazine were to conduct flow tests of various brand 600 CFM carburetors for air flow; which brand do you think would have the greatest airflow. Jon
I don’t know much about dual 4’s, what would be the preferred setup for my stock cad? I am ok with adapters and modern carbs…
@carbking or anybody with knowledge… Thoughts on the spread bore (manifold / Offenhauser) to square bore (Edelbrock) carb adapters? Are they needed? Edit: Since posting this I have determined that the dual bolt flange on most aftermarket manifolds is a hybrid flange and designed for either square or spread bore carbs. Also, the butterflies on my Eddy 500 are not “square”. Primaries are 1&7/16” and secondaries are 1&11/16”. I’d agree that spacers are not ideal, but won’t completely discount them as they do add to the plenum volume and that might make a difference. Only testing would answer if they help or hurt. They certainly don’t look good and introduce twice the amount of leak potential. I will not be using spacers and will pay close attention to the “fit” or “seal” of the carburetors.
Since you asked, I am NOT a fan of square bore/spread bore conversions. Period! Either pick the intake you like OR the carb you like and then acquire a carb to match the intake or an intake to match your carb. Jon
scoob_daddy - the original Cad Carter WCFB's or 4-GC's would be a good choice. Call if you wish to discuss, phone number and hours below. Jon
Cars that used carburetors that would fit your manifold without an adapter include '52-'53 Oldsmobiles, '52-'56 Buicks, '52-'56 Cadillacs, and '54-'56 Chrysler products. All of the aforementioned General Motors products used both Rochester 4GCs and Carter WCFBs. Ford products used a Holley carburetor with the same pattern in the same era, but I wouldn't suggest using them.
Thank you Jon. I never thought about magazine dyno tests like that, but it makes complete sense. Kinda like political poling.
These are the Weber "Edelbrock's". 600's on a C26 intake. They are tempting me to put them on my auction find 327 in my '29 CC pick up. (and I wonder why this truck is taking so long...)
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