svtbarry

I have a twenty gallon sumpted ( is that a word ) aluminum fuel cell mounted in the bed. It had a roll over venting valve fitted that just vented into the air but this allowed fuel to 'splash' out when full and it stunk. So I have swapped it out for a roll over valve that has an #8 AN male thread on top and attached a NOS blowdown tube to vent. NOW, when the gas gets hot ( and it gets very hot I have learned ) the noxious fumes travel along the tube and condense and the setup drips fuel like a still. I'm thinking I could just bend the blowdown tube and poke it through the floor of the bed to vent to the outside but this seems rather dangerous. WHATCHA FINK GUYS? Your thoughts please and please let me have some picks of your fuel cell setup.

harley#356

15 gal cell here. Check valve on the vent line of the tank. Ran that into aluminum tubing, did a loop, then through the bed floor. No fuel smell issues in the bed or around the truck or underneath. Used a breather filter on the vent under the bed to keep anything from crawling up there

Tim Skelton

Is that a fuel cell, or a high-tech mobile moonshine still?

svtbarry

Thanks Harley, that's very very nice. Sort of what I had in mind but the NOS blowdown tube obviously isn't going to be long enough so I'll look out for some aluminum tubing. Thanks again.

Good one Tim :-)

harley#356

haha too funny

I really got to get a pic of Madenterprise's fuel cell setup over here. Now thats one NICE friggin setup!

No prob. I ordered the aluminum tubing from Summit, along with the fitting to adapt hard tube to the AN port on the cell. Came in a roll and I just straightened it out, polished it up real fast, and used a spring bender kit from home depot and a 2 liter bottle of pepsi to get the loop bent in it.

svtbarry

Got a problem with your breather setup. I was under the impression that a breather was used to let air IN so as not to create a vacuum in the tank, but in fact it seems that the tank gets pressurerized and a breather is needed to let air/gas fumes OUT. Anyway, I consructed a mock up of your design today using clear plastic tubing. What happens is that the gas fumes condense in the coils of the tubing to the point that they fill and then the gas ( now liquid ) is pushed through and out to the atmosphere. So using this design we are infact spraying gas out to the open road.

harley#356

never had an issue with mine. You'd have a lot of fuel condensing in that loop to fill it up to the point that its filling up the entire loop and pushing out the down tube. With how fast gasoline evaporates, its never been an issue.

svtbarry

Yeah, maybe it's because I run an A1000 fuel pump. It really churns up the gas in the tank and it also gets the gas very hot. I'm at a bit of a loss what to do now though. Any ideas anyone?

harley#356

I've got a Weldon 2025A 1400hp fuel pump, that sucker moves some fuel!

svtbarry

Who knows, maybe your 'coils' are filling up as well and you just dont see it 'cos they're aluminum and not see through. I can't see an alternative to this unless I vent the gases straight up allowing the condensed gases to form and fall straight back down. This would still mean the bed filling up with stinky ( and explosive ) gases.

harley#356

If its condensing in there, its not that much. Like I said, I've got no fuel smell in the bed, and no fuel smell under the truck when I'm working on it, and no signs of the breather being wet or dripping fuel. This is also how JL does the vents on all their fuel cell setups.

#1lightningfan

Barry ,

You have to run the straight piece off the fuel cell, before the coils, high enough to not let fluid get in the coils. Meaning you have to pay attention to the length of the cell and factor theat into the straight portion of the tubing before the coils, or when you stop gas is just going to move forward and squirt up in the coils.

Also if oyu are worried about fuel smell the plumb in a charcol filter of a mustang or something.

Lastly the pump is a magna fuel 4301, not that it matters in this scenario, but just so you know.

svtbarry

Thanks for that. Yeah, I'm gonna play with the length of the 'up tube' before the coils today if I get some time. Like you said, if that 'up tube' is long enough before the coils start maybe the gases will condense and fall back down before getting trapped in the coils. However, first tests show the gases condensing throughout the entire length of the tubing evenly. The coils fill up pretty quickly even just at idle ( maybe 10 mins or less ). It only takes the first coil to fill the lower part of the bend and then the gases kinda send it spluttering around and finally exit. I cant believe just how powerfully the gases are projected through the tubing. I always thought that the purpose of a breather vent was to let air in, not gases out. Anyway, I'm off to play with it now. I'll report back!

svtbarry

OK, so today I spent quite some time playing with various lengths of straight tubing ( 3/8 bore ) before the coils start. I tried differant lengths from close to the top of the cell to right up to the underneath of the tarp. Same problem no matter how far away the coils are from the fuel cell. As I previously mentioned, the hot fuel gases condense along the full length of the tubing so as it circulates through the coils it collects to the point that it blocks the lower part of the coils and then is pushed along and out to the atmosphere. I'm thinking that maybe a straight tube and an inline filter before a single u bend and then down and through the floor may be the answer. The filter would have to 'breath' both ways though - wouldn't it? Any ideas on what kind of filter would do the job?

#1lightningfan

I guess I dont get what you mean by condensing? The fumes are turning to liquid?