Dragster Fuel Tank Vent Problems

Having problems with a new fuel tank. After burnout, backing up and sometimes during staging fuel is coming out of the vent. Tank is in front of the car. Vent tube runs from the front/left top corner of the tank and back towards the driver. Return line fitting is on backside of tank facing forward on opposite side of the vent.

Any suggestions?

 

Can you run less fuel? I know i fill mine a little full when it pees from the pits to the staging lanes. Some times as it expands from heat in the lanes it pees some more. To fix it i try and only fill it to a certain point.

If you run, say, an inch less fuel in the tank, would you have enough for the run? That should cure the slosh.

When i had my last tank made (different car), the guy built an elaborate anti slosh system. It still peed when i over filled it.

 

Do you have a check valve or roll over valve on your vent tube. Make sure your return line is not putting fuel in your vent line. Previous post is true, to full, fuel will expand

 

what size is your vent tube? Dave

 

Brad...
when we made our tank we put the fill cap in the back on top, and vented under the cap out the bottom of the tank. we used a 3/4" tube and brought it up real close to the cap. i cut an angle facing the back of the tank.....works pretty well.
Darren

 

thats how mine is

 

mines not a dragster but i put a #6 line on my vent and i put 3 small loops in the line and it fit nicely between the tank and chassi it havent had a problem since

 

This is a really nice looking tank. What are the different size return fittings for. Looks like #6 and #8 fittings. What is this tank used on?

 

Did you just zip tie the line to the chassis or tank? I like this idea.

 

I did check to make sure the return line wasn't causing the issue by removing the cap during warm up. Hard to tell the effect when the fuel is sloshing around in the tank. Would you be concerned with a check valve causing back pressure?

 

5/8 diameter on the vent

We have a #8 return line from the fuel system.

Are you still in the Roller Skating Business?

 

The #8 is the main return from the shutoff valve the othe #6's are lanch fuel return control and 2 high speen returns. The tank is for a 10.5 truck with a BAE 526 Hemi

 

u have the best guy for the job in your back yard call me 240 793 5740 i will tell u his name

 

Yes I'am still in the skating buisness.Dave

 

Looking at pic, was wondering how many gallons tank holds, do you fill it right up and do you have a baffle inside at your vent tube.Your fuel is probably sloshing around after burn out, (car settels down) when you back up and stop (sloshing) and when you stage(bumping in off the brake pedal(fuel moving frt to rear and back again. Just something to think about. Might look like your return line might be leaking (streak down tank in picture maybe fuel is spraying from there?)

 

u have the best guy for the job in your back yard call me 240 793 5740 i will tell u his name

Come on don't keep secrets , go ahead and Spitzer it out

 

it just has a wire tie to the chassi on it but it works for me before that someone was always wiping up alky no problem since the line is fairly long i will measure it if you would like to know how long itis to leak now it would have to travel through the 3 loops and the rest of the line and thats not going to happen

 

jim,
if those loops fill with fuel, have you not lost your "vent" since the line has fuel in it?

 

i know what you saying before it would cause a problem it would suck the fuel back in the tank if there was that much in it wouldnt be like its blocked off it would act like a syphone hose at that point

 

Thanks for all the great ideas. I am going to try the loops first.
Brad