New to swirl pot

So, I have two pumps that deliver 6 PSI each, left and right side.

I also have a 6 port swirl pot.

Eight thursty webers set to 3.5 PSI with a regulator at the frnt end of the fuel rail.

Here is the question: the reg. will maintain 3.5 on the fuel rail and dump the excess from the pumps to the...?

Do I want to dump back to one of the tanks? Since it would have no pressure, the regulator spill off could just get dumped back.

Am I missing something with this?

Thanks for any help.

Tru
 

Randy V

Admin
Lifetime Supporter
You could make the 3.5 PSI Regulator in the fuel rail a "dead head" with no return...
Not all regulators will work as dead-heads - but most of the common ones from Holley will.
Edit -
Please post a diagram of your intented install..
 

Ian Anderson

Lifetime Supporter
Supporter
Why use a swirl pot with Webers?

Each Tank to filter to LP Pump to non return valveto regulator to T pece to carbs

No need to clutter the system with extra complexity and swirl pots

The carbs will not run dry under braking with throttle closed and have enough in the float chamber in case the pump sees / sucks some air (normally under braking) and immediately in acceleration the outlet is covered in fuel again

Sure drive on a long downhill on an empty tank and you could drain the webers float chambers - but then the tank would have to be pretty empty for this to happen

Ian
 

Terry Oxandale

Skinny Man
Supporter
The dead-head is the most simple version of what you want to do. Returning to the tanks helps in distribution of the heat absorbed by the fuel rails and tubing (which is a major issue with my set-up), by mixing with the cooler tank gas. But that only last so long.
 
Last edited:

Ian Anderson

Lifetime Supporter
Supporter
Ok so you are drawing fuel from the left tank

It means you will overfill the right one

If you insist on doing this you need solenoid valves to direct the fuel back to the tank being drawn from or a cross over valve

Ian
 
That looks like a fuel injection setup. Check with your friend again.

The pump's prime is determined by the tank to pump path, not after the pump.

Normally you would put a coarse filter before the pump and a fine filter past the pump to protect the injectors or carbs. Too much restriction before the pump could cause cavitation.

There are several discussion about swirl tanks on this forum, but usually only related to fuel injection.

-Bob Woods
 

Terry Oxandale

Skinny Man
Supporter
Ok so you are drawing fuel from the left tank

It means you will overfill the right one

If you insist on doing this you need solenoid valves to direct the fuel back to the tank being drawn from or a cross over valve

Ian
Absolutely. I valve mine to where I'm always drawing from the same tank that I recirculate back to. In my set-up, I swap to running the "other " pump, on the fly, which does what Ian states above, starts transferring fuel from one tank to the other without re-valving.
 

Mike Trusty

GT40s Supporter
Lifetime Supporter
Ian and the others are correct that you do NOT need a swirl pot with webers for all the reasons mentioned. Use an inline regulator with no return. I would suggest setting it closer the 3psi. How you draw from the different tanks is another question. I would suggest having a selector valve so you can draw from the tank of choice with a single pump system. This would allow you to have fuel only in the tank opposite of the driving position if you were doing track events and help with weight balance. If you want a pump for each tank then provide a check valve at the discharge of each pump and select the tank by switching the pumps. The pump for each tank arrangement also allows the pumps to be located low in the car below the normal fuel level of the tank which means there will be no pump priming concerns.

If you have injection you absolutely need a swirl pot.
 
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