I was "here" all summer and its news to me too...Whoa. I really have to get caught up on everything I missed this summer
Whats Up @jjvw...how is a fuel cell supposed to be done, in your opinion?
Jeep TJ rear wheelbase stretch with existing Rubicon Express long arm kit
- Thread starter paulrobbyn
- Start date
Whats Up @jjvw...how is a fuel cell supposed to be done, in your opinion?
I've said it before...It would be enlightening to work for a week or two in this shop, taking insults and beratement...but learning SO much.
It went up twice, once to prop it up in place with the mounting holes lined up under the studs and sitting at the same level it would be mounted at. We moved it up until the corners of the frame reinforcement were touching the tank. Checked to make sure it was sitting where it would be if it went straight up and then we measured the gap at the mounting flanges. That gave us the amount we needed to mark on the tank for the depth of the clearance work and we added an inch for safety. Quick eyeball inside the frame gave us how far inward the cut out section had to be.
Dropped it back out from under the, laid out the cut lines, made the cuts and then it went back up to see if we missed anything. We didn't so it was dropped back out and sent out to the aluminum welder to close up.
My favorite is one we did with a stock tank.
The picture is a bit hard to figure out but it shows enough to have you scratching your head for a bit to figure out what we did.
I would think the plastic tank is easier to modify...good heat gun and you can push and stretch that stuff almost anywhere you want...until you go too far, anyway!
Fuel cells (by assumption are not tanks under the rear of the rig) have a range of issues. They are loud, they take up precious space, the filler neck is problematic since they work by gravity mostly so they need slope to get down to the top of the tank.
That puts the filler neck opening for fuel in above the top of the tub rail if you use the typical pump arrangement.
Tank volume is calculated at 231 cubic inches per gallon of fuel. If you use a conventional rectangular cube design assuming you start at the front edge of the cargo step, that creates a 13-15 gallon tank simply due to minimum dimensions.
The pump ring is between 7-8" in diameter so that puts the front to back dimension at about 8". 12" is a reasonable height with some expansion area. Tub width is roughly 36" if you want a snug fit.
At those rough numbers, every extra gallon of fuel moves the rear wall into the cargo area almost 1/2". 19 gallons would move that wall back 2 1/2" roughly for a total of about 10 1/2". That is a lot of cargo area to give up to run a fuel tank not under the back of the rig.
The two big issues are capacity and over the tub rail filler. The filler means that you mount something in a hardtop that you don't remove, unhook the soft top to fill or make a velcro flap. The worst part is you will smell every drop of fuel you spill.
An answer is to make use of space that isn't typically used for cargo and to lower the top of the tank so a filler can be installed in the side of the tub. My answer looks something like this. 18.2 gallons that encroaches 4" into the cargo area and has a tub side mounted filler neck.
This is genius. So the filler will be located below the rub rails and above the flares on the driver side? One YJ "feature" I really liked is the placement if the fuel filler door behind the license plate. Can something like that be done here as well?
And you still left room for the cupholders behind the center console.
Hmmmmmmm ... I have a two month paid sabbatical from work that I've been postponing due to covid .. it'll lapse next year if I don't take it.
No idea since this filler neck is right behind the B pillar. If you put it behind the license plate, it would have to flow uphill a very long way.
No even close. In fact the slicing off of the cupholder is what determined the forward face of the tank. The owner adjusted the seat back angle, then how far forward he sits on the seat base. That determined the tank capacity.
Plastic will stretch way below the ignition point of gasoline, generally around 180 degrees F. Some polycarbs and acrylics are higher...anything polycrystaline, really. Even there, you're going to about 350 degrees F. Gasoline needs about 475 degrees F to ignite without a flame or spark.Lol. Like find the flash point?
By too far...I mean stretch the plastic too far and tear it.
The flash point of gasoline is VERY low...which is why its so easy to ignite with a match or a good shot of static electricity.
Blaine and I discussed turning a Savvy gas tank skid into a stretch tank and reformimg the factory tank to fit. I had the idea to use a heat gun. But it turns out that the plastic tank is multiple layers of different plastics. Heating and successfully reshaping could be easier said than done. Blaine said to just force the tank into the skid.
Though once done, we are still left with all the compromises of a regular stretch tank. The frame arch doesn't move with the axle and I don't like the idea of chopping the springs into it. And the frame side control arm mounts still need to move back.
I never liked the traditional fuel cell options, which meant a stretch wasn't really a consideration until now.
Ya, I was joking a bit. I work with thermo formed plastics way more than I like. I assumed that was what you meant by too far.