The Stovebolt Site Forums The Shop Area Engine Shop Using Single Carb Intake with Fenton Dual Headers?

Hope everyone is doing well! I'm having major issues getting my dual carb setup working correctly and I'm at the point of simply going to single intake and single carb. Can I do this without changing the Fenton dual headers and dual exhaust? If so, what intake would I need to use?

I have the stock intake and the fenton headers on my 261, no problems. You may have to bend or make a new rod from the belcrank on the side of the engine to the carb( depending on your carb, I'm using carter/weber) the linkage may be ok with the factory carb.

I have run the stock intake manifold with Fentons a couple times, it works fine.

Tommy

Is your Carter/Weber performing better as the factory carb? and did you have to change anything for getting the correct air/fuel ratio?
Thank you

Jianis

You've got one too many carburetors- - - -no wonder you're having trouble! Unless you come up with two very small-venturi carbs and match then perfectly, dual carbs are nothing but a headache, as it seems you've discovered. If you're running a 235, you might choose a Weber 2-barrel with progressive throttle linkage, or the original Rochester or Carter 1-barrel. Either setup will be an improvement over the average 2-carb installation.
Jerry

Tommy,

You answered the original question but this topic has wandered a little in response to your mention of dual Carter-Weber carburetors.

The "one too many carburetors" conjecture might be a bad analysis/guess with regard to the dual C-Ws.

My limited experience using dual Carter-Weber carbs sold by Tom Langdon is that they do not seem to be too much for a 261 with dual Fenton exhaust headers. The C-W carbs are, I think, the model 740 which was also a Motorcraft part and was used on 1600cc Escorts. Actually, these dual C-Ws seem to be under-sized, but Tom Langdon informed me that larger secondary jets might help this situation. Someday I might give this a try.

Nonetheless, my dual C-W set-up has been no heartache. They look a little too modern but they have been 100% reliable and foolproof (me being the fool in question). They are also very economical to run, unless I push them (they get 18 mpg at 60 mph but 12 mpg at 70 mph).

Jianis,
I have a holley/weber carb, not a carter/weber, my mistake.I replaced the stock rochester model B ,the holley/carter worked great from the start no problems runs great.

Tim,
I'm about ready to go to the two carter/webers on an offenhauser manifold. I have a small cam ( howard m4f) from Patricks and the engine runs great now with the single holey/weber on it. but it feels like it need a little more.I had put a monojet carb from a 250 and it really seemed to have more power through the mid range. So I guess the small primary on the h/w is less than the stock monojet.
I bought the h/w from Tom Langdon about a year ago and it has been flawless, I also did the petronics ignition at the same time.

The Holley=Weber carburetor was used on 70s Ford Pinto and Mustang II which had approximately 2.2 or 2.3 liter engines.

As Jerry suggested, two of these might be a little much for a 261?

One solution to getting more volume without dealing with the 2-carb headaches might be to modify a stock 1-BBL intake manifold to accept a single Rochester small-bore 2-barrel like the 265's and early 283's ran. I've considered doing that, but never got around to setting up a manifold in a milling machine and making the necessary carb base adapter. Just bolting on some sort of aftermarket adapter leaves the original 1-BBL flange in place and defeats the purpose of having more venturi volume available- - - -the stock manifold flange becomes the choke point.

Back in the 1950's Dad used a similar technique to outrun his competitors at the local dirt track- - - -a single big Zenith 2-BBL with removable venturis bored out for maximum volume, and a modified stock single-carb intake on a flathead Ford V-8. He was outperforming 3-carb engines and had none of the carb synchronizing headaches the other racers had to deal with. Everybody was running methanol, BTW, and our fuel mixture included a healthy dose of Hydrogen Peroxide as an oxidizer. The fuel was so corrosive they had to run the carb dry every time the engine was shut down, or it would eat the bottom out of the float chamber. The fuel tank was a stainless steel beer keg!
Jerry

That adapter is a good beginning, if the hole in the original manifold is bored bigger to accept the increased volume the 2-BBL is capable of delivering. I'm thinking of making the hole inside the 1-BBL flange about 1/2" or so larger, and installing a pressed-in sleeve to account for the fact I'll be opening it up into the heat riser passage.
Jerry