Progressive set-up with two 94s

N

Notadufus

Junior Member
Recently was told of a '40 Ford owner, who had one full-time carburetor, with another one that had no idle circuit.....as in a progressive set-up. (with an aluminum two carb intake.)

According to the person telling me, the one carburetor worked normally, until the engine reached a certain RPM, then the 2nd 94, began to open like a four barrel carburetor.

I'm 77 and never seen anything like it, except for progressive 3 carb intakes..

I doubt the claims that it'd work well, as a two-carb intake positions each of the carbs over ports, that would require the fuel-air to travel different lengths until the secondary carb opens.

Just curious if anyone has witnessed a similar set-up?
 
I used such a setup on the 59A engine I had in my '35 coupe in High School, and it worked well. I used idle circuits on both carbs, but I suppose it would also work with just one. Note that with a stock single carburetor manifold the end cylinders fuel path is longer than the center cylinders, and that works fine. The progressive linkage opens the secondary on throttle position, not RPM, which would vary depending on how much load is on the engine when the throttle position starts to open the secondary.
 
I would think the air/fuel distribution would be very poor. Might seem ok on the street but would be interesting to see the dyno results. If you were so inclined it might be ok with a slingshot setup. Not sure I understand why anyone would want this type of arrangement, why not just open both carb at the same rate? What would be the advantage to progressive linkage on two carbs? I see a lot of negatives and little to no positives.
 
40 engine with 2-94's, tried progressive, could not ever get it to work. finally changed the jets, had both idle circuits working and used both carbs all the time and it ran pretty good.
 
We install a four barrel carb with the CFM correct for the flathead, with mechanical back barrel linkage. Dual carbs look great, but usually don't function well except for sustained high engine speed such as racing.
 
Oh, but it's about the look don't you know!!! If you want to go fast install a SBC, if you want to look (be) cool it has to be a flathead. But myself I perfer even more grief, 3 x 2!!! :)
 
I think this may be a little more complicated than it looks at first glance because of the different types of dual manifolds. Surely, progressive carbs on a super dual manifold is not a good idea. Also, probably not such a good idea on regular dual manifold with the carbs equally positioned in the center of the manifold. There are, however, some older regular dual manifolds with the carbs more biased towards the back. These could probably be made to work satisfactorily in a progressive mode with the front carb as the primary.

That being said, I agree with "supereal" about 4 BBL carbs being a better choice.
 
This the set-up I use on my 276ci engine. Non progressive. Works very well and has been for a few years. Gets 14-18 MPG depending on my right foot!
 

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Progressive linkage with two 94's can be done, but most use direct linkage where both carbs open at the same time and both have idle circuits. It's more efficient than using progressive. Tri-power would probably be preferred by most with progressive linkage.

Sal
 
I'm a big fan of the intake shown by estout81, Offy makes a very similar one. This
and the Offy (made for 8BA motors ) can be used on early flat motors when a GM
or similar alternator is chosen. Very very good fuel distribution with a center mounted
generator or alternator ( as mentioned). Progressive is OK for 3x2's but can be a pain
for 2x2's. In my experience poor fuel distribution and the requirement for the secon-
dary carb to be air tight mucks up and adds unnecessary problems to a normal fun
straight 2x2 setup. OMHO>
Charlie ny
 
I recall some years back, someone on a flathead forum who ran progressive linkage on one of those 'Y' manifolds, and raved about it.
 
That's what I referred to as a sling-shot manifold. That would resolve the distribution issues.
 
I have a progressive setup on my avatar with a slingshot "Y" adapter on my stock manifold. Got everything from Charlie Price in FL. Has worked great since installed and except for getting tumbleweed out of the fuel bowls when I ran into one on my way back from the '16 LARS, it has not been touched or rebuilt in 3+ years of driving it all over the country ..... gas mileage is around 14-17+ at speeds of 65 + ...... I would not hesitate to use this setup again .....
 
Thanx to everyone who replied.

I believe the name Charlie Price, from Vero Beach, came up, during the conversation. I live about 70 miles from Vero Beach...... might run over there some day and talk to him about this issue, but meanwhile, I'm gonna leave well enough alone.

I agree that the "Y" intake, (Eddie Meyer?) with the carburetors positioned high and very close together, might work progressively OK. My intake looks just like estout81's

But, like CharlieNY replied, the trouble of setting up the progressive linkage and carb tuning may not be worth the effort.

I've built a few flat-heads, with both of the carburetors working together, and they all ran well.

I guess it's best not to "fix" what ain't broken!

estout81, your flat-head's a beauty! I've got a Chevy distributor in my 8BA, what is yours?
 
My first experience with dual 94's. I am running the Offy intake with straight linkage on my 8BA. After I finally got them adjusted correctly using a unisync and lots of forum member input I am pleased to say that they work great.
 
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