What is the purpose for a fuel sump?
Uhh, no, it doesn't...
You need a sump so that fuel stays near the pickup under cornering, accleration, braking, etc. Without it, yes, your fuel supply will be interrupted at some point.
It's like using an oil pan without baffles or trap doors.
You need a sump so that fuel stays near the pickup under cornering, accleration, braking, etc. Without it, yes, your fuel supply will be interrupted at some point.
It's like using an oil pan without baffles or trap doors.
Why dont i have that problem with my setup now? 97gph inline holley fuel pump feeding a 780 carb? I plan on running an inline 255lph when i do the swap and i dont understand why just running a higher psi will matter. The volume is the same.
Teching In
Joined: Jul 2007
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The fuel in the tank will actually slosh away from the pick up so your pump will be sucking air for a short period of time. It has nothing to do with what pump you're running or what kind of pressure the pump is making.
So then i can just go ahead and keep running just a dual feed sending unit and keeping the tank full is all right? I dont plan on road coursing or anything like that, strictly straight line.
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Verdad Gallardo No, it doesn't!!!!!!!!!! Moronic statement of the year...
Unless one pump has some magic fuel magnet in it, fuel will drift whichever way the car does. Sumps are like a reserve mini tank for the pickup.
Not running one is akin to using a lighter to see in a gas tank.
Unless one pump has some magic fuel magnet in it, fuel will drift whichever way the car does. Sumps are like a reserve mini tank for the pickup.
Not running one is akin to using a lighter to see in a gas tank.
The stock 68 firebird tank does not have one correct? The engine in it now can lift the front wheels with no fuel starvation so why do i need one for an ls1 that is what i dont understand. I'm not a "becasue we said so" person.
I've typed it twice now. If you don't want to run one, then don't post the question..
Every factory car with EFI, EVERY SINGLE ONE, has one. Its not because they like spending more building a car than they have to...
Any smart drag racer uses one as well, including myself in my old 10.09 3400lb GTO...
Every factory car with EFI, EVERY SINGLE ONE, has one. Its not because they like spending more building a car than they have to...
Any smart drag racer uses one as well, including myself in my old 10.09 3400lb GTO...
He's not running EFI. He has a carb. The fuel might slosh away from the pump for a couple of seconds, but you probably won't ever know it because of the fuel in the float bowls. It's not good for the pump to run without fuel around it, but you can most likely get by with it that way for a while. I just wouldn't plan on doing it for very long.
I asked to see the purpose you just now answered it ALL EFI cars have one. This makes sense. carbs have float bowls that retain a small ammount of fuel so if they were starved for a second or two they could maintain. EFI however must miantain a constant pressure over the rails inorder to function properly. This is my reasoning based on your comment "Every factory car with EFI, EVERY SINGLE ONE, has one." That's what i was looking for.
Haha thank you now im sure. I just put a brand new tank in. hate to take it back out. How come i can run a fuel cell and it will work? Are fuel cells sumped or is it just because the fittings are at the bottom of the fuel tank? I am carbed now but the ls1 for the bird is sitting in my dining room im just waiting on my cam to put it all back together then its getting swapped in. My engine theoretically will run without a sump with efi though right? i would like to get everything right with the engine before i mess with a fuel cell.
If your pump and filter are lower than the outlets on a cell filled with foam (no fuel slosh) than gravity will take care of almost all of it...
Once you get a fast drag car with a carb, that millisecond that you will lose fuel will be enough to drain your bowls and lean out the motor.
You have to remember how much force there is pushing that fuel towards the back of the car when you're going down the track. One millisecond of the pump going dry will drain your bowls out for sure.
So you can get away with it with a slow car as long as your tank remains full to a certain level. Once you start going fast, you're all done.
Once you get a fast drag car with a carb, that millisecond that you will lose fuel will be enough to drain your bowls and lean out the motor.
You have to remember how much force there is pushing that fuel towards the back of the car when you're going down the track. One millisecond of the pump going dry will drain your bowls out for sure.
So you can get away with it with a slow car as long as your tank remains full to a certain level. Once you start going fast, you're all done.
Never heard of sumps, but i never had to on my 95 formula or 01 z06. My car is maybe a 12 second car as it sits. I'll just cut my tank apart and weld one in i suppose then
