Banger with dual 81's, fuel pump/gravity?

I know there are regular banger threads but I could not find a good answer. I have 2 freshly rebuilt 81 carbs, a thomas head and a thomas intake. Do I have to run a pump? I have seen some that say no and some that say yes. I want to keep this as simple as I can, no messy lines running all over the place. What do I need to do? This is a very 1930's style hop up so that is the reason I am hesitant about using a pump. It is a model a motor so no fuel pump boss on the block.

 

It looks like the gas tank outlet will only be a couple of inches above the floats, so it might work if you never want to go uphill.

I'm using the lowest pressure version of that little box-type electric pump on my twin-81 fed V860 and it works really well.

 

Add the pump.

 

I changed to 12v after the first 6v pump went out & I didn't want to wait for a 6v to be ordered. 12v elec fuel pumps are readly availble. Use a GM internal regulator alt. the stock A starter & ignition could handle it.<!-- / message -->

 

I ran my fuel line out the gl*** bowl and down to the pump thats bolted to the toe board then it exits out the top through a filter then the line comes up and crosses the down line and over to the carb. Its hard to see yet. I put it on after haveing trouble with hills and with it starving due to low preasure.

 

No way would I ever run an alternator, it is a 1930's era hop up. Has to have the generator and no, the look alikes will not do.

 

Why not use an old hand pump ala early Dodge & Cadillac (a**** others). Here's what I'm going to use in my T on an A ch***is; 1922 Cadillac hand pump & a 1918? Dodge pressure gauge mounted in an old Autolite bezel (originally for a Clum switch & ammeter)

 

Do you have any pics of your set up?

 

A buddy of mine ran alky needles and seats. Big orifice, theory being volume over pressure. With just the gravity feed he ran around town no problem. After reading the above though, I can't ever seem to remember seeing it go up a steep hill...

 

I attempted to run a single 97 without a fuel pump. I have heard people say that it can be done and have even seen pictures of cars set up that way. But, after a fair amount of effort, I just couldn't keep it from starving out under sustained full throttle. I ended up using a fuel pump (B motor) and have had no problems since. Not saying it can't be done.

To calculate head pressure, you get .434 psi per foot of elevation. To get the 2 psi minimum that your Strombergs want, you would need over 2 feet of elevation from your fuel level to the carb inlet. That doesn't take into account the friction loss of your fuel lines.

-Mitch

 

Gonna have to run a pump, no way are you going to run 2 carbs on gravity feed and have drivability. I tried running a single 97 with a full tank of gas years ago and could not get past 35 mph without starving the float bowl. I put a 12volt pump on and have been motoring as fast as she'll go since.

 

By all means run a pump, just hide it and you will be very happy. I have tried it with out and it didn't work, with 2-81's it will run great.--TV

 

Hats off to you Homeboy. This has been my only car since April, so it's more of a matter of, I dont want to be limited to 6V.

 

I'm running 2 81's with an electric fuel pump. It also has an 12v alternator. I stopped running generators years ago.

 

I have had no problems running generators and I want to keep this car as 30's based as I can so that means 6v and generator. Do they make a low pressure 6v pump? Should I run the line down to the frame and back up again to the carbs?

 

you dont have to use the frame if you dont want to. you can bolt it to the floor or toe boards. Mine on the toe board as i have to get at the battery and MC but there is all sorts of room on the p***enger side for stuff. Make sure you use a rubber mount or wood. Nothing is more lame than noisy fuel pumps and fans.