Fuel Tank In Spare Location

[derf]

I've been doing some searching and can't seem to find exactly what I'm looking for.  I've seen some ideas but they weren't quite right.

 

I know I can grab a fuel cell and toss it in the bed and it will work but I don't want to do that.  I have plans for the bed and there's no room for a fuel cell taking up space.  I'm going to be converting to triangulated 4 link in the back and the links need to go where the fuel tank is now.  So the stock location will be otherwise occupied.  That leaves the spare location.  And I'm not worried about that because I'm going to 40"+ tires so I'm relocating the spare into the bed anyway (part of why there's no room for a fuel cell in the bed).

 

I know dimensions are important so I will point out that I have a short bed.

 

I'm going to keep the stock frame as a base (no tube frame) but I'm not opposed to removing the X frame and replacing it with 2 or 3 gusseted straight members.  That would give me a couple of inches to move the tank up so it doesn't hang down so far.

 

My first thought is to do an XJ tank.  Get a sender from a compatible year for the gauge to work right but then also make sure I have a good pump for whatever engine ends up in the front (still haven't nailed that part down).  20 gallons is probably plenty for what I'm going to do.  I'm also thinking that I could get a skid plate from one of the many aftermarket companies.  I suppose a YJ tank would also work and have a choice of skid plates as well.

 

Who has done a "spare" tank swap or has done any research on it?  Any advice or links to things I didn't find in my search?

[BeatCJ]

Just as a spit ball, but I would bet a CJ or YJ tank would fit, too. My CJ has a XJ fuel pump adapted to run the 4.0 fuel injection, I suspect it wouldn't be horrible to adapt a Comanche sender to that.

[Sir Sam]

My friends 97 MJ has the 97 XJ tank where the spare tire was. It sits a little low but it fits. 

[omega_rugal]

1 hour ago, Sir Sam said:

97 MJ

 

[derf]

I've looked at the CJ and YJ tanks.  They are shorter top to bottom but only hold 15 gallons.  That's probably enough though so they are options for sure.  Turns out a replacement TJ tank is hard to come by.  Though I may be able to get my hands on a used one...

 

I'm going to keep looking at various other options out there, compiling a list of dimensions of tanks to see what really fits well.

 

When I get the build started, I'll drop a bunch of pictures of what I end up doing.  My plan will probably include building some structure to mount the tank as well as having solid mounts for a skid plate that, along with a hitch, will protect the tank.

[Sir Sam]

9 hours ago, omega_rugal said:

 

 

Take an MJ, install all the stuff from a 97XJ, and make a 97MJ. Then call it a 97MJ so you don't have to explain that its a 91MJ with all the stuff from a 97XJ each time you refer to it.

 

Just like how I'm building a 01MJ.

[derf]

i don't have exact measurements from bumper to back of the axle but I'm estimating maybe 30" of room.  Given that, I do have some room to play with some options.  There's a tank that's 33.5" wide between the frame rails, 29.75" front to back, and 13.125" tall that could possibly fit.  But do I really need a 42 gallon tank from a '98 Suburban?

 

An XJ tank would fit pretty well.  An 18 gallon tank from a 98 Blazer is about the same width, a little longer front to back (22" vs 20.75") but it's shorter (10.5" vs 13") so it should tuck in better.  It should also have a compatible sender for the fuel gauge and the pump will be good for even a V8 swap.

[derf]

Random update but I got to toying around with the measuring tape under the bed this last weekend.  The X brace on the frame doesn't leave much distance between it and the end of the frame, at least on a short bed.  Maybe 12" or so from the frame end of the X to the back of the frame.

 

If you're willing to let the tank hang down under the X brace you do have quite a bit of room.  Enough to fit a TJ tank easily (hanging pretty low though), with room to spare on the sides and front to back.  If you bias it towards the rear bumper, you have plenty of room for a wheelbase stretch and/or upgrading to one ton axles.

 

I'm probably just going to pull the bed off and do some custom welding on the rear frame.  I'm going to a triangulated 4 link with coil overs in the rear and I'll probably end up cutting out and replacing the X brace to make room for things while still having some structure to replace it.  I like the idea of the TJ tank as long as I can tuck it up close to the bed floor so that's the route I'm leaning towards right now.

[EUREKA]

On 4/21/2020 at 8:03 AM, derf said:

i don't have exact measurements from bumper to back of the axle but I'm estimating maybe 30" of room.  Given that, I do have some room to play with some options.  There's a tank that's 33.5" wide between the frame rails, 29.75" front to back, and 13.125" tall that could possibly fit.  But do I really need an?

 

An XJ tank would fit pretty well.  An 18 gallon tank from a 98 Blazer is about the same width, a little longer front to back (22" vs 20.75") but it's shorter (10.5" vs 13") so it should tuck in better.  It should also have a compatible sender for the fuel gauge and the pump will be good for even a V8 swap.

 

I am definitely interested in a larger than stock tank in the spare tire location, and I happen to have a long bed. Maybe the 42 gallon tank from a '98 Suburban is for me.

[Smokeyyank]

I know you said no fuel cell but.....don't think something like this would work? 

 

Footprint is plenty small to not take up a ton of space. Plus it gets it up from the rocks. 

 

https://www.jegs.com/i/RCI/821/2171A/10002/-1?gclid=Cj0KCQjwp4j6BRCRARIsAGq4yMEsPi_QdgNbbjn2l2czGGhHFnKyGK_S2jB4M8QNxI853ctvoqqlOWUaApm5EALw_wcB