Fuel Cell Vent

[macgyvr]

So I finally got the jeep together (pics later) and took it wheelin this past weekend. I'm running a 95 so I have a return fuel system. I'm using the e2000 pump and the holly dual pickup system. The tank has a rollover valve built into it. Off the rollover valve i ran a line up the back of the jeep with a small filer on it to keep debris out of it. Here is my problem.

When decending a hill i get fuel leaking out of the vent. Sometimes while just sitting on level ground with the jeep running I will get fuel leaking out of the vent and sometimes, fuel will spray out of the vent. How can I mount this thing so that I dont have gas all over the back of my jeep.

It also should be noted that while wheelin the outside temp was in the mid 80s, if that makes a difference.

mac 'no smoking around my jeep' gyvr

 

[Ludakris]

have you tried it without the line attached? it sounds like it is somehow creating suction on the line..

 

[macgyvr]

have you tried it without the line attached? it sounds like it is somehow creating suction on the line..

without which line?

mac 'gasistooexpensivetowaste' gyvr

 

[woody431]

Completely off topic, but what size tires and axles you running? Jeep looks great!

 

[87manche]

possible that the tank is building pressure?
What if you run the tank without the filler cap on it. See if you get fuel spray.
Does the rollover valve have a tube that goes into the fuel? I just don't see how it's picking up fuel to spray out.

 

[Kaczman]

If you run the vent line into a 540 degree loop you shouldn't have any premature spewing issues. I'm running a vent line off the same style in tank roll-over valve and it's never leaked a drop.

You can see the vent loop and filter secured to the cage.

-Jon

 

[macgyvr]

well it was the first time out for the jeep in this setup (over 2yrs on jackstands)....

i did fill the tank completely to the top...i think a combo of that and the warmer temps built a lot of pressure in the tank. i like the 540 spin...jesse from the badlands shop suggested to run a ball valve shut off because when the jeep goes on its side the ball valve in the rollover will really only be effective when the jeep is completely turtle....so i think i'm going to reroute the vent so that i can shut the vent off when its on its side then run something similar to the 540 and then make sure the end of it is as far away from me as possible...

any other ideas...

running 39 inch red label crawlers with a 60 up front and an eaton out back...i need to take some poser pics and post the suspension that was hillbilly built in the garage...so far seems to work decent...have a few things to work out...

mac 'no smoking' gyvr

 

[93xjmark]

I'm one of the tech/safety inspectors for a 4x4 racing series in the Northeast.
www.cc4w.org
Because rollovers are a common occurence, we require all fuel cells have a rollover valve, and a "doubleback" vent line.

The vent line comes off of the rollover valve, and extends past one side of the cell, and then pulls a 180* turn and extends past the other side of the cell. Then it drops down below the bottom of the cell. (Many of the racers put a plastic inline fuel filter on the end of the line to keep dirt out).
What this does, is it prevents fuel spillage when the rollover valve doesn't have enough volume to "lock" it's self closed. The rig can land on either side, or upsidown and still have a highpoint air loop.

Here's a pic of a doubleback vent line.

 

[macgyvr]

i'm just glad you posted a pic...

cause ya lost me for a second...

i guess if i'm still blowing fuel out of that...i've got problems

mac 'makes sense' gyvr

 

[Ramsey]

is it neccessary for it to extend past the side of the fuel cell?

 

[5-90]

The idea of it makes sense - that allows for the formation of an air pocket unless it rolls over just right...

Doesn't look like it goes too far past, just about an inch or so. Just enough so that a full fuel cell will still end up with an air pocket (read: "vapour lock") in the vent line, and that will minimise spillage.

5-90