fuel cell vent

Have a 22 gal poly fuel cell in my Galaxie. No return, just vented out the bottom of the trunk. I place a rubber cap over the vent tube while it's in the garage to prevent fumes from escaping. Sometimes I forget to remove the cap when I start it and have even left it on while driving it which probably doesn't help the pump or the performance. A friend suggested to reverse a fuel filter which would let the fumes escape but not let any thing in . I can't see how this would work, if I blow into either end of the filter air comes out the other end, seems like the fumes would escape either way. Any suggestions?

I have my vent hose coming out the top then it runs back down the side of the tank I have never noticed any gas smell even when it sit in the trailer for weeks at the time. I ran mine this way so if it ever flipped over gas would not run out of it I run alky now and still don't get any smell in the shop or trailer I have a 3/8'' vent line.

Just want to make sure I don't have another garage fire like I did a few years ago. Thank heavens my big Gal was spared, the garage wasn't so lucky. Really glad I had insurance, AND a very good claims adjuster! She wasn't hard to look at either .
She made it possible for me to get it completely rebuilt better than it was before    . Probably wouldn't be so lucky this time.
Thanks.

Did the vented fuel cell cause the fire ? What ignited it ?

On my hot rod, i used an old Holley needle / seat assembly in the vent hose. Break off the threaded part, skooch it up the hose. Lets air in, wont let fuel out.

Dave C. wrote:Did the vented fuel cell cause the fire ? What ignited it ?

No, nothing like that. The inspector said it was an electrical problem. Some kids going to school noticed the smoke and rang the door bell. Not thinking clearly I opened the side door to the garage to try and put out the fire and the air caused it to start blazing. The fire dept got here pretty quick but they couldn't get the fire hydrant they hooked up to open, it was stuck shut so they had to go to an other one but by that time it was too late. They did manage to get the double overhead door torn apart and pushed the Galaxie out. It wasn't hurt too bad. Got a new paint job and new rubber molding and a couple of dents fixed where tank from my torch outfit and part of the overhead door fell on it, $9000 damage. The interior was ok lucky I had the windows rolled up.

JACKAZZFLATZ wrote:On my hot rod, i used an old Holley needle / seat assembly in the vent hose.  Break off the threaded part, skooch it up the hose.  Lets air in, wont let fuel out.  

Now that's an idea, old school thinking

Sorry to hear about your fire. Glad your car is ok.

My neighbors had a fire and he lost all his tools, video collection, his truck and his boy's 86 Porsche.

GT300TD wrote:
Have a 22 gal poly fuel cell in my Galaxie. No return, just vented out the bottom of the trunk. I place a rubber cap over the vent tube while it's in the garage to prevent fumes from escaping. Sometimes I forget to remove the cap when I start it and have even left it on while driving it  which probably doesn't help the pump or the performance. A friend suggested to reverse a fuel filter which would let the fumes escape but not let any thing in .  I can't see how this would work, if I blow into either end of the filter air comes out the other end, seems like the fumes would escape either way. Any suggestions?

Here are a few pictures of how I run mine, the top left fitting is the vent the right one is the return line(not in pic), in the picture it is 1/2" aluminum hard line (braid or other works too) with a 360* loop which prevents fuel from sloshing out, it goes to a bulkead through the trunk and in picture 2 you see a mini K&N filter which stops the fumes, I have ran it this way and my garage does see open flames nary a problem.

IMO having a 360* loop in the tank vent line isn't the best idea. While it might reduce one problem (amount of fuel slosh exiting the vent tube) it can also cause another problem when traped fuel sitting in the bottom of the 360* loop (from slosh) in effect becomes a vent blockage in the tube. Your best bet is to just use a 180* loop in the vent line placed as hight above the tank/cell as possible.

And if fuel sloshing out the vent on a street driven car is the concern you could always use the same high 180* vent loop, but place it as far away from the tank as possible.


As for having a filter on the end of the vent line, using some form of a paper or screen filter to keep trash out of the tank is fine as long as it's not too much of a restriction. But if a given brand/type of filter is restrictive enought to stop gas fumes from exiting the tank vent & filling up the garge on a hot day, then it's probably too restrictive to use on a vent in the first place.

You also want the end of the tank/cell vent tube to exit the body as close to the car's R/L centerline as possible to reduce the chance you might drive/back over any sloshed fuel on the track or street. Same goes for any puke tank vents on a car, (radiator, trans, etc) you don't want to drive/back over that stuff either.

DILLIGASDAVE wrote:IMO having a 360* loop in the tank vent line isn't the best idea. While it might reduce one problem (amount of fuel slosh exiting the vent tube) it can also cause another problem when traped fuel sitting in the bottom of the 360* loop (from slosh) in effect becomes a vent blockage in the tube. Your best bet is to just use a 180* loop in the vent line placed as hight above the tank/cell as possible.

And if fuel sloshing out the vent on a street driven car is the concern you could always use the same high 180* vent loop, but place it as far away from the tank as possible.


As for having a filter on the end of the vent line, using some form of a paper or screen filter to keep trash out of the tank is fine as long as it's not too much of a restriction. But if a given brand/type of filter is restrictive enought to stop gas fumes from exiting the tank vent & filling up the garge on a hot day, then it's probably too restrictive to use on a vent in the first place.

You also want the end of the tank/cell vent tube to exit the body as close to the car's R/L centerline as possible to reduce the chance you might drive/back over any sloshed fuel on the track or street. Same goes for any puke tank vents on a car, (radiator, trans, etc) you don't want to drive/back over that stuff either.

Here I stand to disagree a little, the vent in this case is on a closed system , ultimately to release pressure build up in the tank so it does not become pressurized, the other factors involved in my thinking is the volume of air in the 1/2" hard line which runs the entire length of the car as well as the 6" tall 180* loop with a 360* loop in the middle, the system can vent into the 1/2" line however it cannot reach the carb as there is a bypass valve installed in the engine compartment (only opens under the stated pressure requirement) further both enter or exit above the fuel cell 6" so it essentially allows the vapour to be encapusalated in the lines of the system...venting internally , not externally, however if the trunk was open the fuel cell was full and the sun was beating on the fuel cell it would allow the liquid, or vapour to travel the line (with resistance-loop) it is a foam filled cell so the slosh is minimal likely will not reach 3" of the 6" available. If the vapours pressurised enough it will just push whatever fuel is in the loop around the loop and into the filter, at that point you might smell it but likely nothing will hit the ground. Example have you ever left a full gas can in the sun with the vent cap closed...the gas can will balloon until it finally blows off the vent cap, if the vapours have enough pressure to balloon a plastic container and a vent cap it has enough pressure to push a few ounces of fuel through a smooth line.

Drove it to a car show yesterday, without the cap on the vent and noticed a gas smell in the trunk even though I had the trunk lip up at the show and a gas smell when I was in the car. It's not strong but still there. I have never had a problem with gas sloshing out but don't go around corners all that fast in this 'boat'. I removed the foam shortly after I installed the cell because the filter before the elec pump was picking up small pieces of foam.
Now I have a few ideas to try. Thanks for the input guys .

I have the same problem in my tbucket. Some people have recommended to use a charcoal canister (ie: autowrecker) on the vent line.

jasonf wrote:I have the same problem in my tbucket. Some people have recommended to use a charcoal canister (ie: autowrecker) on the vent line.

Looked that up and the prices and size would not fit my situation. Thanks

JACKAZZFLATZ wrote:On my hot rod, i used an old Holley needle / seat assembly in the vent hose.  Break off the threaded part, skooch it up the hose.  Lets air in, wont let fuel out.  

Seemed like the easiest and less challenging (for me ) suggestion, so I tried it and it works
Good old 'hilljack' engineering

GT300TD wrote:

JACKAZZFLATZ wrote:On my hot rod, i used an old Holley needle / seat assembly in the vent hose.  Break off the threaded part, skooch it up the hose.  Lets air in, wont let fuel out.  

Seemed like the easiest and less challenging (for me ) suggestion, so I tried it and it works
Good old 'hilljack' engineering  

So what size line are you using for your vent?

1/2" alum fuel line. I put two different sizes of rubber shrink wrap tubing around the needle/seat and forced it into the line.