School me on fuel cells


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Wildman

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jeeps got 20yrs and 200k on OE pumps i'm not sweatin that. not reworking the vessel is all i want from this, 1 and done.

if i could find the right plastic tank i'd never even consider aluminum and house it in a steel can w/lid.

@toximus , since your here how tall was the inner box on that GR tank ? did it come up high enough to keep baffle balls or tubes off the pump assy? did it have room for the sending unit to function?


I've had to replace my pump once in my TJ and I only have 83K miles on it BUT may TJ has sat a lot which I'm sure wasn't good on the pump. Finding a tank that fits the stock pump/sending unit seems to be the bigger issue since GR & MB both make their fuel cells taller than needed.

I've still got to get under mine and measure to see how much room I have and if I could fit a GR tank.
I had to cut out the box for the TJ pump to fit in and for the sending arm to fit. It's roughly 4"x4"x1". Since the TJ pump has a built in sump I didn't see a purpose of keeping it anyway. Besides, I think a trap would work better than their maze if that's indeed a concern.

A baffle wall or two to slow sloshing on fast turns seems to be a decent benefit even if only to stiffen up the tank and stop fuel from hitting the sides so hard. But even then I'm not convinced it's necessary.

Anyway, I'm happy with how my cell turned out. That said, if you can fit it under the Jeep, it's easier and leaves more room inside for other stuff.

If a GR tank will fit then I agree it's a better idea than a fuel cell.
 

mrblaine

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alright.............so i tore into the stock pump assy. i had to see/know whats goin on there.

what i find is, the can is our anti-starvation fuel containment device.
on the bottom of the can is the pre-filter.
inside the bottom of the can is a rubber washer and a steel washer. this seals the captured fuels outlet. above that sits another smaller strainer/screen device. this is mounted to the bottom of the pump by means of a rubber adapter.
then the pump is inline, into a push through seal and tube. this tube is crowned with a spring to keep pressure on the bottom end and keep it seated.
that tube from the pump is mated to the tube protruding down from our plastic caps by means of another push through seal.
the pumps height is limited by the 3 slotted legs that connect the top to the can.

so i'm not seeing a way to fit a Holley mat unless it can be fit to the existing can flange (which is not much of anything to grab and hold with any type of clamp). any alteration to the can bottom could result in the can not holding fuel unless it remains submerged as well.
so the cap holds the regulator. this dumps back through the cap into the can. this can is fairly deep and holds a good bit of fuel. Aeromotive has a similar design for their fancy high $ pumps that surrounds the pump in foam inside a plastic bowl........our can is about 3-4x as deep as their bowl.

so we don't wanna be punchin holes in the can or cuttin the bottom open........it is our fuel trap/baffle.

now baffle to me is not a fuel trap, and a fuel trap doesn't not qualify to me a baffling.
baffling is to control fluid movement, to me. splitting the vessel into smaller compartments, so liquid has less room to gain momentum and slow it's weight transfer from being abrupt and immediate.

i found 1 tank that's listed as 15gl, 30x12x12 that has walls that qualify as baffles. i don't like it has a vented cap that would need changed. so it'd need a ROV added, no need for the sending unit (but want the hole to get plastic baffles into) and i would not use the foot mounts, opting for a full surround mount to help control side wall flexing. not sure if i wanna go for it, but is another option.

so part of this is, i think i was gettin tripped up trying to provide what already exists in addition to anti slosh, which was a fuel trap. not saying it's not possibly beneficial to add another, but maybe not completely necessary.

maybe y'all knew all this, but i think i have a slightly better understanding now.

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The only part you are confused about is also the same part that is most important to you. The can is not a fuel trap for the purpose of using the fuel to run the motor, it traps fuel when you fill the tank and uses that to keep the pump cool. If you study it some, you will discover that the only fuel pick-up into the pump is inside the filter sock and it has no way to use the fuel in the can.
 

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Have no idea if there is one that does/will since I've never played with any. But that wasn't the issue Someguy was talking about. He's worried about the stock pump not touching the bottom of the tank and fuel slosh and fuel starving. So if you were having a custom tank built with an aftermarket pump setup you could mitigate these issues. From all the reading I have done out of tank pumps seem to be part of the problem becasue they are not cooled. They now offer in-tank aftermarket pumps so will they last longer?
I've only ever ran a electric fuel pump once and I never had problems with it but I only owned that rig for 2 years.
Which mechanical pump did you run when you weren't using an electric?
 
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Wildman

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Which mechanical pump did you run when you weren't using an electric?

Whatever was the stock pump for that rig. I switched my Samurai from stock mechanical pump to a electric pump when I'd rebuilt the engine and THOUGHT I needed a electric fuel pump. I didn't but I never changed it back.
 

someguysjeep

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The only part you are confused about is also the same part that is most important to you. The can is not a fuel trap for the purpose of using the fuel to run the motor, it traps fuel when you fill the tank and uses that to keep the pump cool. If you study it some, you will discover that the only fuel pick-up into the pump is inside the filter sock and it has no way to use the fuel in the can.
the small strainer on the inside does not allow fuel to be drawn from the cup? it fits right over the inlet port. if it cannot pull from the cup why would there be a strainer on the inside? the only thing it can possibly strain is whats in the cup.

so now we are back to trap and baffles....
 
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mrblaine

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the small strainer on the inside does not allow fuel to be drawn from the cup? it fits right over the inlet port. if it cannot pull from the cup why would there be a strainer on the inside? the only thing it can possibly strain is whats in the cup.

so now we are back to trap and baffles....
If you don't fill the tank to where it fills the can by flowing in over the top, fuel would never get in and the pump could burn up. The way you solve that problem is put a one way check valve on the bottom to fill the can to whatever level is in the tank.
 

someguysjeep

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If you don't fill the tank to where it fills the can by flowing in over the top, fuel would never get in and the pump could burn up. The way you solve that problem is put a one way check valve on the bottom to fill the can to whatever level is in the tank.
sorry to keep pursuing this but i'm trying to understand.

the regulator does route some fuel to the cup? pressure overflow or engine cut-off return? is this what accounts for the can being fuller than the surrounding tank level or would this all be from the last fill-up spill over?
 
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mrblaine

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sorry to keep pursuing this but i'm trying to understand.

the regulator does route some fuel to the cup? pressure overflow or engine cut-off return? is this what accounts for the can being fuller than the surrounding tank level?
The can has a higher level because doesn't drain out of the can. The top of the can is below the full level of the tank so when you fill the gas tank, that fills the can. If you only fill it halfway, the check valve in the bottom lets fuel in to the tank level.

When you start thinking of it as a little bucket to hold fuel, it makes more sense.
 

someguysjeep

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The can has a higher level because doesn't drain out of the can. The top of the can is below the full level of the tank so when you fill the gas tank, that fills the can. If you only fill it halfway, the check valve in the bottom lets fuel in to the tank level.

When you start thinking of it as a little bucket to hold fuel, it makes more sense.
thanks as always.....i can understand and see that (now).
 
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someguysjeep

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ok here's another query, since i'm not a DD and it'll be hauled in and out of any off-road playgrounds, can anyone justify why i might need more than 10-12 gallon cell? really like to keep things a small as possible.
smaller ='s confined and confined means fuel can't get to far away, it's a lot easier to keep fuel at the pump in an 18x12 than a 30xanything. and that would fit behind the passenger seat and help offset some of my weight when goin solo.

then i had a thought about the Holley mats.........what if we just cut the connector caps off it? then we could take our bottom screen roll it up and slide it into the hydramat. once inside let it unroll get the plastic adapter into the hole we just slid into and attach the mat with our OE strainer inside it. our strainer would have constant contact inside the mat, think it would fly?
 
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Fouledplugs

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ok here's another query, since i'm not a DD and it'll be hauled in and out of any off-road playgrounds, can anyone justify why i might need more than 10-12 gallon cell? really like to keep things a small as possible.
smaller ='s confined and confined means fuel can't get to far away, it's a lot easier to keep fuel at the pump in an 18x12 than a 30xanything. and that would fit behind the passenger seat and help offset some of my weight when goin solo.
If you’re looking at a stretch as well as looking at a tank that small, genright’s first gen 11 gallon alien tank allows 9 inches of stretch and is under $1k, while the first gen is still in stock.

On the other hand, if you want the same amount of stretch but more fuel capacity, their new 15 gallon Alien tank (Gen2) is available for purchase.
 

toximus

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can anyone justify why i might need more than 10-12 gallon cell?

How much gas do you typically burn in a day out wheeling? I can't remember a day using more than 10 gallons, even being out 8+ hours. If you can fill up at night at the trailer I don't see that being a problem.

That said, you're only saving maybe 10lbs of aluminum by making a 10gal tank instead of 20gal.

Edit: If you play at the dunes or desert you'll probably burn more. I was burning 20 gallons every hour or two the last time I was playing on the sand...Although a gas station or truck/trailer typically isn't far away.
 
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someguysjeep

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If you’re looking at a stretch as well as looking at a tank that small, genright’s first gen 11 gallon alien tank allows 9 inches of stretch and is under $1k, while the first gen is still in stock.

On the other hand, if you want the same amount of stretch but more fuel capacity, their new 15 gallon Alien tank (Gen2) is available for purchase.
don't think it'll fit i got a little ambitious on my stretch. and i definitely don't have 37" between frame rails anymore, i'm 36" to the outside of um.

How much gas do you typically burn in a day out wheeling? I can't remember a day using more than 10 gallons, even being out 8+ hours. If you can fill up at night at the trailer I don't see that being a problem.

That said, you're only saving maybe 10lbs of aluminum by making a 10gal tank instead of 20gal.
that's my thought often not far from the trailer especially when local. i could toss in a can for long trails out west and always have xtra on the trailer. again not so much weight as less space and more fuel confinement, less baffle balls, and i'm not carrying 3+gl of fuel i almost never need.
 
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For me I use any where from 12-17 gallons of fuel depending on the length of the trails I am doing for the day. But a lot of my trails up here in the PNW are longer than some or more than one trail connects into another. This is why I have wanted to stay at a minimum of a 20 gallon tank/cell.

Plus I don't know how thirsty my new engine might be.
 
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someguysjeep

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my ONLY semi local off road spot is 1.5hr away and the property is maybe 3500 acres. i could run the whole place all day and never burn 10gl.
i don't think them Colorado guys get out to far in a days play, if i ever get that way. maybe if i get out to meet some of y'all in the desert this april, that'd be the time i might burn a little more.
 
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my ONLY semi local off road spot is 1.5hr away and the property is maybe 3500 acres. i could run the whole place all day and never burn 10gl.
i don't think them Colorado guys get out to far in a days play, if i ever get that way. maybe if i get out to meet some of y'all in the desert this april, that'd be the time i might burn a little more.

Yes I agree that where you wheel can dictate the type of fuel capacity you might want to have. Every fall we use to do a 24 hour trail run where we hit every trail in the Little Naches basin. And it would take up anywhere from 24 -36 hours to run all the trails. But it was a fun weekend and there was always tons of O'SHIT moments to laugh about.
 
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someguysjeep

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i'm all down for stuff like that. but Ohio just doesn't support it.
several yrs back they got all over OR parks for liability and they jacked up the insurance. so high on these places it forced them to close up and only a couple made it this far and they still struggle to make enough to keep the doors open. extreme southern Ohio has a couple more options being so close to KY.
 
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Wildman

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i'm all down for stuff like that. but Ohio just doesn't support it.
several yrs back they got all over OR parks for liability and they jacked up the insurance. so high on these places it forced them to close up and only a couple made it this far and they still struggle to make enough to keep the doors open. extreme southern Ohio has a couple more options being so close to KY.

Yes from my little exposure to back east wheeling I know you guys have it rough and I am glad I live out here where it's still open. You need to make a trip out here and wheel once your rig is done. We'll just have to carry some extra fuel for you....
 
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