Fuel tank design

[Paul New]

I am still in the planning stages of the rebuild on my car and just want to know what makes the best tank it will be a narrow tank all the way to nose of the car. Just slightly worried about the burp after the burnout with the 1 1/4 line. Also different types of vents I have had 3 different styles of vents one out the top with the coil, one out the bottoms of tank into the air gap below the cap, and the latest style is flapper in the cap that Gary Eickman built for me. Possibly thinking of going with the style like Parks uses.


Sent from my iPhone using Tapatalk

[rooman]

I generally use the front to rear tube deal (usually with a tube coming off it at 90 degrees at the mid point). I put a horizontal baffle high in the tank to stop fuel from getting into the tube under at the hit or under braking and run multiple vertical baffles down from that to stop front to rear slosh. I will try to post some photos later today.

Roo

[Paul New]

Thank you Roo not that my tank is horrible but some times I do see a little slosh coming from my vent on a launch! Your insight is much appreciated

[dreracecar]

Ditto on the front to back vent tube. it works the best both in accel and decel.
Absolutly no reason to run that big of a fuel line and with the tank so far foward and the tank not being tall (for head pressure) 1"od tube is more than enough volume.
 Pumps push fuel and really dont like to suck and is easy to break vacuum under a hard decell if there are any air pockets in the tank. The bigger the line causes the extra fuel weight to move forward because its not a tall tank with 5 gallons of fuel pushing down on the outlet keeping the line filled.

[GlennLever]

This is a very old picture of the tank setup Roo Man is talking about

[Paul New]

Ditto on the front to back vent tube. it works the best both in accel and decel.
Absolutly no reason to run that big of a fuel line and with the tank so far foward and the tank not being tall (for head pressure) 1"od tube is more than enough volume.
 Pumps push fuel and really dont like to suck and is easy to break vacuum under a hard decell if there are any air pockets in the tank. The bigger the line causes the extra fuel weight to move forward because its not a tall tank with 5 gallons of fuel pushing down on the outlet keeping the line filled.

Never thought that a 1" line was big enough to feed a 110 due to the size of fittings they sale for them, that is why I went with a 1.25 line thanks for the input

[dreracecar]

Gone 6.80's with a 1"od to the inlet of a 110 pump that feeds a -8 to the BV.
Fuel pulls faster from the center of the tube line than the fuel thats rubbing the ID of the tube. The smaller the od of the tube the larger the center fuel core there is, the larger the od the smaller the core is. This is matched to pump size and head pressure/ line length. If this was a funnycar/altered and the tank was tall and back towards the pump, 1 1/4 would work because the head pressure of the fuel is above the pump inlet and thats what is feeding the pump, but since you are much further away and the head pressure is below the pump inlet, you need a stronger draw from the tank(larger center fuel core)

[Paul New]

Good information what size of fuel line does an A/fuel car require not that I run those E.T.'s now but who knows

[ricardo1967]

Gone 6.80's with a 1"od to the inlet of a 110 pump that feeds a -8 to the BV.
Fuel pulls faster from the center of the tube line than the fuel thats rubbing the ID of the tube. The smaller the od of the tube the larger the center fuel core there is, the larger the od the smaller the core is. This is matched to pump size and head pressure/ line length. If this was a funnycar/altered and the tank was tall and back towards the pump, 1 1/4 would work because the head pressure of the fuel is above the pump inlet and thats what is feeding the pump, but since you are much further away and the head pressure is below the pump inlet, you need a stronger draw from the tank(larger center fuel core)

Humm, well, not sure if I’m reading your words right Bruce… the restriction for a fluid to flow in a pipe is proportional to the velocity of the fluid (just like aero drag in a car). The fluid molecules touching the pipe have zero speed and the molecules in the center of the pipe have maximum speed. Larger pipe diameters results into proportionally lower speeds, therefore if flows easier. Now, the law of diminishing returns applies here, so there will be no practical gains using a 2” fuel inlet pipe where the 1” meets the restriction criteria.

[Paul New]

Started the tank project this weekend bent the top, sides, and front






Sent from my iPhone using Tapatalk

[Paul New]

Looking to buy some aluminum tubing 1/2", 3/4", 1", and some 1-1/4" 5052 to match up what I am welding it to or do I buy 6061?


Sent from my iPhone using Tapatalk

[rooman]

Paul,
        unless you really go shopping around what you are going to find will be 6061. Depending on how much you need you may find it easier to simply go to a big box hardware store (Lowes, Home Depot etc). Just make sure that the tubing is not metric with fractional labels. At one time some of those stores carried the Stanley brand and it was sourced from China and not the size as labelled. I had a couple of heated discussions with Stanley's "engineering" staff over the issue.

Roo

[Paul New]

Thanks! Did not know they carried aluminum tubing

[dreracecar]

The friendly folks at Aircraft Spruce have what you need and they sell by the ft without a cut charge for a real decent price 5052 and 6061.

 If you are building racecars, this is a must have catologe---- they have everything!!!!