two carb setup

4

4ford

Senior Member
hello all.
just got this motor running and runs well thanks to all that helped ! I have a few things to ask, as you can see in pic the fuel lines is there anything anyone can share about different ones maybe pics of yours? to give me some ideas. second the carbs the carb that is closest to the alt seems to have more vacuum then the one close to the fire wall. the primary one is that one closest to fire wall and has the choke hooked to it is this right? or should it be the other way? it has 400 heads and 1090 offy intake. 1941 ford 46 motor 59ab....any thoughts??

thanks
 

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4Ford - your choke is correct

Here is my pic004.jpg
 

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Reports are that small air filters are too restrictive. I have taller ones.
 

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Yes, air cleaners can be restrictive.
I have a Cobra dual carb setup for a 289.
I had the carbs airflow tested with and without two small air filters. There was almost 100cfm less with the two small air fliters. Large oval filter with K&N showed little to no cfm loss.
 
nice clean look on the fuel lines adileo.4ford, do you mean like a throttle body vacuum leak or just trying to get them adjusted. I got one of those unisyn jobs and kept tweaking away at it.
 
4ford said:
hello all.
just got this motor running and runs well thanks to all that helped ! I have a few things to ask, as you can see in pic the fuel lines is there anything anyone can share about different ones maybe pics of yours? to give me some ideas. second the carbs the carb that is closest to the alt seems to have more vacuum then the one close to the fire wall. the primary one is that one closest to fire wall and has the choke hooked to it is this right? or should it be the other way? it has 400 heads and 1090 offy intake. 1941 ford 46 motor 59ab....any thoughts??

thanks
Click to expand...

Your fuel lines will be ok for putting around on the street.
A better setup can be seen in the pic.
Most street setups fall short in the fuel supply volume at wide open throttle.
Whatever pump setup you have, it needs to be able to maintain 2 lb or more at wide open full load throttle.
You can observe the fuel pressure with a TEMPORARY mounted fuel pressure gauge on the cowl OUTSIDE the cockpit. Never mount the commonly available fuel pressure gauges in the cockpit. Potential fire hazard.

Most "hot rod" air cleaners are restrictive. A good rule of thumb is the filter area for each carb should be at least 4 times the carb throat area.
This is hard to achieve with individual cleaners. Most hot rodders don't like the look of the modern "covers all the carbs" type cleaners but it is about the only way to get adequate area with no restriction. Here again it depends on how fast you want to go or how old you want to look.

Your variation in vacuum between the 2 carbs is probably due to the choke in only one. It will probably won't hurt anything if it is just a small difference.
 

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The vacuum I can feel it when I have both chokes open just buy putting my hand over carb. I think it's a notesable difference
 
how about something like this for an air cleaner? more air?? what do ya think. would it make any difference to make the choke on # 2 closer to the alt. then the stock choke rod will work well?
 

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the choke on my forward carb is straight up and down, and fixed in place. I'm running 97's though. you maybe could choke that out somehow though and work on the back carb. make sure there are no leaks, use propane or whatever. if no vac leaks, vac hopefully can be evened out with idle set screws. I did have issues with linkage being interfered with make sure the linkage between the carbs is loose so you can set both carbs up with idle, then lock em down. I apologize if this is all second nature to you. I'm not a good judge sometimes of peoples skill sets. I'm pretty new at this, couple years running duals. K&n makes an air cleaner that is unrestricted and 4 1/2 inches tall. I don't have pics online. those are free enough that they make no difference on or off. Can't remember if the top and bottom and bolt /wingnut came with them.
 
so if I hear this all right..... the primary carb should be closest to fire wall. with the choke also on that one? or could it be the other way?
 
From my prospective, I think the average "close mount" dual carb manifold setup is more for looks, as compared to actual performance. A single four barrel would work better.
I have a Offy Super wide mount manifold on my 59AB with a pair of 97's, of course this application requires a side mount generator.
The front choke is wired open, the rear carb choke is attached to a modified choke cable.
Fuel is delivered via a fuel block on the firewall supplied with fuel from an original type of fuel pump backed up with an electric pump near the tank that is switched separately.
The air cleaners are stock type oil bath that have been modified to hold disposable paper filters.
The whole setup might not be to pretty, but it is functionable.. I drove the car to work everyday for years through summer heat and winter blizzards.
 

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