Dual carb intake

[KMeredith87]

I'm looking into running a dual carburetor setup on my 30 pickup and wondering what thoughts/experience you all have with that. Also I am looking to build the intake from two originals and was looking for any guidance someone out there may have on cutting and welding the two manifolds together. I did search the archives and couldn't find much one this subject.

[Purdy Swoft]

I run dual B carbs on my roadster and my speedster. Its a fairly easy setup with updraft carbs. No fuel pump or pressure regulator is needed. If you've got two good carbs, just bolt them on and go. It doesn't matter if you use A or B Zeniths, Tillotsons or Marvels. I use old original dual updraft manifolds that I found. I first thought about makeing my own manifold from two original manifolds. I read in the secrets of speed journal where Charley Yapp tried this and the weight of the Zenith carbs and vibration caused his manifold to break. If you are good at brazing it could work . A ready made aftermarket manifold would be better and would perform better. A manifold that is flat on top will distribute the the mix to the cylinders better and give better performance. Aluminum dual updraft aluminum manifolds are available and include the linkage.

[Pete]

Originally Posted by KMeredith87

I'm looking into running a dual carburetor setup on my 30 pickup and wondering what thoughts/experience you all have with that. Also I am looking to build the intake from two originals and was looking for any guidance someone out there may have on cutting and welding the two manifolds together. I did search the archives and couldn't find much one this subject.

Here is one that I used to manufacture. It is extremely easy to make at home with hand tools and a welder. It requires one exhaust pipe mandrel bend, a short piece of electrical conduit tubing and some 3/8 flat bar to whittle the flanges from.
It uses 2 Ford 6 Holley single throat carbs. which are available new.
I used to use only one choke and hooked that up to the stock choke rod
with a cable.
I often wondered why no one took up making these setups because they worked so well and were so easy to make.

I would not try welding 2 stock manifolds together. Too many people have tried it and they broke. It CAN be done though.

[silversink]

Originally Posted by Pete

Here is one that I used to manufacture. It is extremely easy to make at home with hand tools and a welder. It requires one exhaust pipe mandrel bend, a short piece of electrical conduit tubing and some 3/8 flat bar to whittle the flanges from.
It uses 2 Ford 6 Holley single throat carbs. which are available new.
I used to use only one choke and hooked that up to the stock choke rod
with a cable.
I often wondered why no one took up making these setups because they worked so well and were so easy to make.

I would not try welding 2 stock manifolds together. Too many people have tried it and they broke. It CAN be done though.

Id like to see this setup a little closer or a bigger picture---that is sweet

[Pete]

Originally Posted by silversink

Id like to see this setup a little closer or a bigger picture---that is sweet

Here are the only 2 other pics I have and they are not very good quality.

[Dave in MN]

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I have a dual mount manifold that is set up for Zenith A carbs. It may not stand up over time as some suggest but I have to try. The second tube is not cast iron and the components are brazed together. Note the structural web between the two primary passages...
I plan to construct a progressive linkage that brings the second carb on when the first is about 1/2 open. I'm still playing with the sketches for this linkage but should have it worked out before next driving season. Hey...living in Minnesota demands a project or two to keep us sane from November to April!
Good Day!

Update: I purchased this thing on eBay. I was doing the research to obtain the parts to build one and up it popped...so I bought it. If I was building this manifold from scratch, I would use all steel tubing. The carb and manifold flanges are available from suppliers. If this thing cracks...I'll follow my first plan to build one from steel tubing. For my purposes of making the progressive linkage work, it is important that the two throttle shafts are in alignment and this thing is dead on!

[KMeredith87]

Thanks for the info guys. I do have multiple spare zeniths and tillys l, which would be better? Purdy, I'll have to keep an eye out for an intake like that but I like the look of the carbs aide by side better. Dave, that's exactly what I'm looking at building, any tips or advice on how you built that one?

[Sparky]

I'd like to build a dual-updraft manifold. Who sells the flanges?

[Dave in MN]

Originally Posted by Sparky

I'd like to build a dual-updraft manifold. Who sells the flanges?

I spoke to Bill Carlson in March of 2011...he had the required flanges.
His FordBarn ID is: BCCHOPIT.
He is very good with fabrication and could build you one to match the photo. He also builds custom exhaust headers.
Good Day!

[Ray in La Mesa]

I've been running the stock A manifold customized to Charlie Yapp's style for 20+ years and it is great. I first welded the second carb elbow on and it cracked a couple of times so went to braising and now no problems. The only change I still want to make is to add a hot air stove to outer carb as the intake runner is so cold cold it drips moisture on even a hot day. I would estimate about a %25 increase in power and no fuel pump with about the same MPG.

[Dave in MN]

Originally Posted by Ray in La Mesa

I've been running the stock A manifold customized to Charlie Yapp's style for 20+ years and it is great. I first welded the second carb elbow on and it cracked a couple of times so went to braising and now no problems. The only change I still want to make is to add a hot air stove to outer carb as the intake runner is so cold cold it drips moisture on even a hot day. I would estimate about a %25 increase in power and no fuel pump with about the same MPG.

Ray, I thought there may be a problem with the outer carb running cold and had a few thoughts of how I may solve the condition. I have attached a rough sketch of what I was going to build. (Note that I bought the one I am showing in the previous picture.) I am planning to place a crescent shaped plate between the dual manifold carb flanges and the carbs to help with heat transfer? I should have it on my car by spring. The crescent shape is necessary to clear the progressive throttle linkage I am working on.
The heat transfer plate shown on the sketch that acts as a brace between the two primary passages is present on the manifold I purchased.

My thought of using a progressive linkage will lessen the use of the outer carb and maybe...if I am lucky...I will not experience the same condensation issue you have.

I am also considering eliminating the idle circuit on the second carb. With the progressive linkage, the choke and idle will be provided by the primary carb. I plan to have the second carb start to open at about 60% throttle and hopefully, the engine will not stumble due to the fuel mixture change. If I have trouble...I'll just eliminate the progressive linkage or greatly change it so the second carb comes into use just above the normal cold engine throttle setting for startup. I want the GAV setting and the choke on the primary carb to handle the needs of a cold startup.

I run a full flow oil filter (A-Ford-able) with the filter on the side of the valve chamber cover. I ordered a manifold from Charlie Yapp to use two updraft carbs and the front carb will not clear the oil filter. The side by side manifold I have and the sketched one looked period correct to my eye and solved the problem with the oil filter. Yaa..I know the oil filter is not period correct but with the filter painted antique green or black it blends in against the rest of the engine.

If you plan to use dual B carbs, the width of the manifold assembly will need to be wider and you will run very close to if not touching the hood. I designed for two A carbs and found I needed to keep them extremely close to each other to avoid having the outer carb touching the hood on my '29 Phaeton.

It's all for fun...they ran great when set up stock but there are a few of us who just can't keep from making a few changes. I think diversions keep me sane....just don't ask the "Is he sane? question of my wife or friends. Their opinions could vary on a daily basis!

Good Day!

[1931 flamingo]

Dave in MN: That is a slick looking manifold, please do a followup on the linkage when it's done, and Bill (BCCHOPIT) is THE go to guy. JMO
Paul in CT

[CarlG]

Originally Posted by Dave in MN

... Yaa..I know the oil filter is not period correct but with the filter painted antique green or black it blends in against the rest of the engine...

If you use Wix filters, they are already painted black and the label on them removes really easy.

Part # 51515

[Model A Speedster]

Im running a matching pair of Tillotsons on my speedster. I tried a matching set on zeniths, but the tillotsons ran better on my particular setup. The only problem ive had at all with the whole setup is sometimes the linkage vibrates down and kicks the idle up a bit. Other then that no trouble!

[Sparky]

Originally Posted by Model A Speedster

Im running a matching pair of Tillotsons on my speedster. I tried a matching set on zeniths, but the tillotsons ran better on my particular setup. The only problem ive had at all with the whole setup is sometimes the linkage vibrates down and kicks the idle up a bit. Other then that no trouble!

What kind of intake do you have?

[Model A Speedster]

Originally Posted by Sparky

What kind of intake do you have?

Its the Vortex intake that Snyders sells.

[Ray in La Mesa]

Dave, I don't know how much the hot air stove will help but want to try it.The reinforcing plate between the runners could help but I doubt it will transfer much heat. I am contemplating progressive linkage too as I have a big flat spot right off idle if I floor it but haven't had time to design & test any. I've just learned to feather it through the hole. Let me know if you come up with anything.
I ran into the same width problem on my '28 pickup with "B" carbs, I ended up with about 1/4" clearance to the hood louvers. It runs great. Also, with a neat era speed trick like this it just has to be painted red.

[Ray in La Mesa]

Dave, Just looked at your sketch again and the vertical reinforcing plate between the runners is necessary due to the weight of the carbs. I don't think I would leave it out.

[tbirdtbird]

Let's bump this and see if we have any updates from anyone.....

[Gabalus]

I would like to put a vortex intake with tillotson or model B carb' on my 1928 Phaeton with model B engine.
A comment ?