Project Fuel Tank

[C5GTO]

Originally Posted by Tom Wells

C5GTO,

I have the Aeromotive 340 in-tank unit in my 1981 Mercury Zephyr wagon. I went for the larger pump because it has a 557.

The wagon has more than 15K street and track miles without any hiccups. And I am familiar with EFI fuel problems caused by uncovering the pickup.

The 24 hour Rolex course at Daytona did not cause any problems during the four track days I ran there last year.

The Cobra is another, older, story. The Aeromotive setups were not around 15 years ago or it would have one also. Starvation occurred in that car even on an interstate when negotiating curves at legal speeds.

The answer to that one was to construct a "box" about 8" on a side below the floor of the tank, putting a piece of perforated aluminum at its top. The pickup is located near the bottom of the box. It was the result of an old drag racer's trick of putting the pickup at the bottom rear of the tank; this box kinda moved that idea to a 3-D version. The pump itself is external.

The "box" has been run 38K miles on the street and many, many track days including Sebring and Daytona among others and nary a burp.

HTH,

Tom

Hmmm...now you have me thinking

Maybe I can add a shallow sump at the bottom rear of the tank, with a lid that traps the fuel from escaping on braking. It would be filled in low fuel condition by acceleration when the fuel sloshed rearward in the tank. The tank is narrow, about 10 inches wide so cornering shouldn't cause a sloshing issue for fuel in the sump. If the pickup and return lines are both plumbed to the sump then return fuel should also ensure the sump has fuel.

I'll have to fit the tank up into the chassis to check if there will be space for this type sump with all the coolant, heater, and A/C lines running under the tank. Even a 3/4" deep sump might be enough to do the trick.

Tom: in case a sump isn't possible, I have a Aeromotive in-tank pump question for you. Is the top of your in-tank unit always above the fuel level? Or is there fuel sitting against the seal when the tank is full? If the later, have you noticed any leakage at all?