Aux fuel tank

[teebes]

This is one of those mods I've been wanting to do for a while now. I'm hoping to get some feedback in case others have similar plans or could help with the research

The limited time I have spent as led me to the following:
*Looking for roughly ~15 gallons
*Looking for a tank with filter/pump integrated for easy integration
*Aux setup will reside will the stock spare tire goes, hopefully my air tank can be repositioned, if necessary
*Aux setup will flow into the main tank, not touching the rest of the OEM setup
*Aux system should engage via manual switch only

Potential tanks...
87-95 wranglers have a 15gl integrated unit. There should be plenty of these around (for pretty cheap) and aftermarket components like skidplates seem to be everywhere.

I still need to get some good dimensions for these and am open to other suggestions. Sp lets hear what yea got!!

Here's one of the write-up's I'm taking notes from: Expedition West Aux Tank Install

[Philberto]

Based on Summit Racing's catalog, the Jeep tank is the way to go if you want skid plate availability, as the only other tanks with around 15 gallon capacity are from small Chevy pickups or from cars. Another alternative is something like a fuel cell: This one doesn't come with a sending unit or pump, but the price isn't bad... http://www.summitracing.com/parts/SUM-293215/ and it's a little safer than a stock tank... Just something to bear in mind... Nice square size with what looks to be corner mounting holes.

[bobbyblaze]

Not all YJs had the 15 gal tank. I had a 1994 YJ with a 20 gal plastic tank. I currently own a 2006 TJ unlimited with a 20 gal plastic tank too. Both come with a light metal protector plate from the factory but you are right, Probably best to get good armor for it.

On the other hand, a square or rectangle fuel cell would be relatively simple to fabricate a mount for. Wouldn't be that difficult to make a skid plate either.

I can get you dimensions of my 20 gal if you need it.

[Zero]

personally id recommend that you take a look at fuel cells. their added strength gives you that extra piece f mind that the fuel will still be there when you need it. there are fuel cells available that have pumps in them already. Just add an inline fuel filter. that will keep maint. simple.

if you want one made. we can do that for you at my shop. if you find one in a cataloge somewhere. try shooting the part # to me in an email, and Ill see if i can get it at cost or something.

[teebes]

I can get you dimensions of my 20 gal if you need it.

Roger that on the 20gl. Yes, any dimensions would be sweet!! Also pics are greatly welcomed

personally id recommend that you take a look at fuel cells.

Good point! At $180 they really aren't as pricey as I had imagined, either The dimensions will give me something to start mocking up in the meantime:
Length (in) 20.000 in.
Width (in) 18.000 in.
Height (in) 10.000 in.

[MrSmithsTB]

Summit has a buttload of cells. Everything from 5-20 gal and then some. Many different shapes as well.

[Dizzlenator]

Problem with a cell is the fact that it's made of metal. Without a skid plate, with rocks, etc, you chip it on a sharp edge to puncture it, you'll simultaneously create a spark, and it'll go up in flames. Buddies Trans Am did that, 2 days after he pulled the stocker and ran the metal cell. Pulled a corner on wet roads too hard, punched a tiny hole in it on a rock on the side of the road and the spark sent it up in flames. Total loss.....Just something to keep in mind. The skid plate is a necessity. I know it'd be more rigid, but the plastic will bend slightly, and cost less, too.

Just my opinion.

[teebes]

Point taken!! I did notice some plastic tanks up on Summit as well, still trying to narrow down the field to one that is nice and 'thin'. Regardless of the tank I'm sure I'll ping Neil for some skidplate action

[teebes]

Here's a 16gl, plastic, that is 9" in height. I found another one that was 2" shorter, but pretty thin aluminum.

http://www.summitracing.com/parts/SUM-290104/

[Dizzlenator]

Now that is beauty! Watching this one intently....

Maybe a dumb question, but how will you fill it? Tie in the stock filler, butterfly valve it, or something, or have it's own seperate fill? Also, how do you plan to counter balance the extra weight in the rear? I know it's not much, but it'll pull you down a little, right?

[teebes]

Counter balance? This is the counter balance to the bumper/winch Hehehe

The filling neck will be a tad tricky. Per CA smog tests, I need to be absolutely certain everything seals up nice and tight and I don't throw any EVAP codes. Leaving the OEM setup as 'stock' as possible will be a must.

Regarding the filler neck, maybe have it pipe out behind the license plate (via some hinges for the plate) or integrate it into the eventual rear bumper somehow?

[Dizzlenator]

I got ya. I was thinking of a butterfly valve set up, something like exhaust cutouts, but splicing in more filler neck could be tricky. I think the license plate idea is good, as well as the bumper. Something else you might be able to do is where the stock spare tire winch thing is. Drill out that hole, and add the filler there somehow. Just a thought.


Come to think of it, you could probably go to a J/Y and look for an old Caddy or something that had the filler behind the plate. Maybe something that will unbolt, that you could mod slightly to have a cap, and everything right there, just plug in the filler neck, and you are golden....

[MrSmithsTB]

Plumb it into the back of the stock tank, use an electric ball valve for your cutoff(explosion proof, of course). Take a trip to a muscle car graveyard and pull the mechanism off of one with a rear filler, mounting it maybe above the hitch?

Something that would work like one of these, with a 12v actuator.

[Trail X]

Behind the LP? You going to snake your filler arm though the rear tailgate hinges?

You should get one of these bad boys for each side!



Now that'd be nice!

Another quick concern...

You want to be able to pump the fuel from the secondary tank into the primary tank. That will require two tubes connecting the tanks. The first will be the fuel sending tube, the other is the air relief because it's a closed system. You also want to ensure that you don't accidentally pump the fuel into your primary tank while it's full. This means you may want to have an overflow tube halfway up the filler neck to prevent overflowing the primary tank (this tube could double as the air releif tube).

Just some thoughts...

[teebes]

Behind the LP? You going to snake your filler arm though the rear tailgate hinges?

Doh, was thinking of my other truck, dumb There should be plenty of opportunites on the rear bumper, especially if I ever get going on the redesigned unit.

You should get one of these bad boys for each side!

I do like the locking idea, but I'd want to be able to fill both tanks without having to move the truck incase the pump hose can't reach. Add a trailer in the mix and maneuverability becomes important.

You want to be able to pump the fuel from the secondary tank into the primary tank. That will require two tubes connecting the tanks. The first will be the fuel sending tube, the other is the air relief because it's a closed system. You also want to ensure that you don't accidentally pump the fuel into your primary tank while it's full. This means you may want to have an overflow tube halfway up the filler neck to prevent overflowing the primary tank (this tube could double as the air releif tube).

Correct, aux pumping into the main. Even if the primary is full it should cycle back into the aux tank. I'll post up some links to some other forums where they've discussed this in more depth.

[Dizzlenator]

Oh yea, I wasn't thinking of where our plate is. I was thinking of the indention on the rear bumper below the gate. It'd be pretty easy to cut that plastic out, smooth it and hinge it. Small panel with filler neck out of another car mounted, and you're ready to go. I think I had the same picture in my head Teebe's.....

[NeilageInc]

We can plumb it right in to the filler neck for both the feed and air relief. As long as it completes a closed circuit the engine will pressurize both tanks and away you go. Just let me know. Thanks Neil.

[Dizzlenator]

Neil, can you clone yourself, and have your clone open a shop on the East coast????? Come on!!!

[teebes]

We can plumb it right in to the filler neck for both the feed and air relief. As long as it completes a closed circuit the engine will pressurize both tanks and away you go. Just let me know. Thanks Neil.

I could see the need to only fill the main tank, majority of the time. The aux would be handy for super cheap gas prices (stocking up) or in prep for trips. I'm thinking the less adjustments to the OEM setup the better.

I plan to start taking some measurements and possible mockup this evening. Neil, this might be another reason to cut up the rear cross members and such

[Philberto]

Does the fuel cell need to be smog-legal, since it isn't replacing the main tank? I hate how we have the CARB restrictions, but I'm not sure if adding an aux fuel cell will be an issue, as long as you don't compromise the integrity of the existing fuel system... just put electric ball valves on the connections to the stock tank, or, alternately, just rig up a filler neck from any obd2 vehicle and mount the fill wherever you want it with the stock cap... As long as it holds pressure, it shouldn't trip any evap codes.