Gravity feed or pump?

[javiern54]

Hi- I am installing a dual carb setup on my '29 and was wondering if the two carbs need to be run with the fuel pump or if the stock '29 tank being higher than the carbs would gravity feed enough into the carbs alone? thanks

[Jordan]

depends. two downdrafts or two updrafts?

[BCCHOPIT]

down draft = pump

[CarlG]

My Weber down draft runs just fine gravity fed.

[hardtimes]

Originally Posted by CarlG

My Weber down draft runs just fine gravity fed.

Ditto ! My avatar will show you twin 81s that run happily on gravity feed!
However, in order to answer your inquiry thoroughly/more accurately, you should state whether your intended setup is updraft or downdraft.

[Jason in TX]

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I run two Stromberg 81 carbs on gravity feed just fine. Just don't forget to shut the fuel off when you are done driving so that a leaky needle and seat doesn't allow your cylinders to fill up with gas and hydro lock the engine. Install a good modern ball valve before the carbs.

[Frank Miller]

How do you plan to drive this? Two carbs wide open uphill might present a problem with less than a full tank. You could run it without the pump and see how it performs. If it appears to be cutting out at higher rpms then install a pump. Judging from the experienced posts you will probably be ok without the pump.

[Jim Brierley]

The '29 tank is lower than the 30-31 so may be a problem under hard throttle for any distance, uphill would be worse. The way to find out is to try it, you can add a pump later if needed. Also some manifolds are taller than others.

[Tom Wesenberg]

Originally Posted by Jim Brierley

The '29 tank is lower than the 30-31 so may be a problem under hard throttle for any distance, uphill would be worse. The way to find out is to try it, you can add a pump later if needed. Also some manifolds are taller than others.

Just put on larger tires. That will raise the tank up! LOL

[BILL WILLIAMSON]

Weber on my '30, with full tank ran sorta' lean, as if it needed re-jetting. Added low pressure electric pump, ran great. Apparently, it raised the fuel level in the carb bowl, and it ran amazingly well. Bill W.

[Ice man]

Living in the Islands(St.Thomas) I had to install a small pump, or run out of gas (half tank) on the hills. There steep down here. I now run a down draft so the pump is always needed. Mine in down on the frame and you don't know its there and it never make a sound. Iceman

[javiern54]

Yeah sorry I should have stated the motor is a '37 with an Edmunds 2 pot manifold. Running two 94's on top. I will give it a go without the pump and see, glad to hear it is possible though. Means I dont have to cut too much into the fire wall..

[aussie]

I am running twin 97 's gravity feed i have no problems even when on a quarter of a tank

[lazlobassett]

I'm running a single 94, bought a 6v pump from snyders, it crapped out very quickly, they sent another and it just gave up today, maybe 20 miles on it? I was running a offy pressure regulator, perhaps it didn't like that? Anyon have similar experiences?

Thanks,

Matt

PS: I am running a B motor with a old cragar OHV conversion, makes things much higher, I doubt gravity would work. Also have ol Burns intake.

[CarlG]

Put a B mechanical pump on it.

[lazlobassett]

Can't, using the port for oil filter system, would prefer that tho.

[Tom Wesenberg]

Originally Posted by lazlobassett

I'm running a single 94, bought a 6v pump from snyders, it crapped out very quickly, they sent another and it just gave up today, maybe 20 miles on it? I was running a offy pressure regulator, perhaps it didn't like that? Anyon have similar experiences?

Thanks,

Matt

PS: I am running a B motor with a old cragar OHV conversion, makes things much higher, I doubt gravity would work. Also have ol Burns intake.

What went bad, the motor or the pump part of the fuel pump?

[lazlobassett]

The pump locked up, I'm not sure it has a motor, it is one of thos inline jobs, might work with a coil. It wasn't a seperate motor & impeller type. I've never taken one of these apart , not that they are serviceable, it would have to be cut.