The Bean

After a lot more welding I rolled it outside with the new rear suspension for the first time. 

That looks wicked.

This  is FANTASTIC 

Nice!  Looks like everyone is getting their chassis rolling!

Next up the mounts for the rear seat belts. my strategy was to weld 7/16-20 weld nuts to some large washers then weld that assembly to the bottom of a .120" plate welded to the frame.

Next up is gas tank placement. I ran into a bit of "measure once cut once" mentality here and I am not quite sure if this will all work as I want it to. Mockup:

Yes the tank is very close to the ground. However it has always been very close to the ground and its actually higher than the lowest part of the frame. Next some tabs for the mounting straps:

They are in funky positions and don't match because they need to clear the sway bar. These may come off and get repositioned.

Finally the first attempt at the trunk floor:

I may end up rebending this as well. I left some extra clearance on the gas tank/spare distance that isn't needed and eats up valuable real estate.

Does anyone run a bladder fuel cell on the street? I have been thinking about crash safety (it is a pinto after all). The tank is really squeezed in between the rear subframe and the back of the frame. The only place to gain more clearance is to notch the rear of the frame and move the gas tank up against the rear bumper. There isn't really anywhere else to put the gas tank though. I need to just mount the tank where it is and move on I think. Thoughts?

In reply to Shavarsh :

The bladders all have a very short life span before  they seep, and the foam which makes them safer in a crash breaks down within 3 years with current street fuels. Metal tanks take much longer to fail without trauma, and are cheap to make. Put big bright brake lamps on it and it will be safer with metal.

I assume the molded plastic liners don't have the seeping issue? I am not too concerned with a bit of maintenance every couple years. Alternatively I may narrow the stock tank (front to back) to gain some clearance/crush space (~1"). Other benefits of the stock tank are the spare tire relief, and the fill neck in the stock fender location. Other ideas to increase safety?

My understanding is that there were two problems with the Pinto gas tank fires. 1. The general lack of crush space in the rear, which was somewhat relieved by the gas tank being outside of the trunk (unlike earlier Fords) and being suspended by flexible straps. And 2. The sharp edges on the standard 6.75 inch differential which cut the tank open when it was shoved against the diff which was partially alleviated by the thick plastic shield retrofitted to the front of the tank.

If not for the sharp edges on the diff (and some E36 M3y Ford execs), the Pinto fires wouldn't have been any worse than early Mustangs and Camaros and all of the small Imports and even the midsized early 80's Malibu.

So I would put the plastic shield on the tank, make sure the tank straps are in right, and that the fill hose is outside the passenger compartment.  I think you have already added more rear structure to the rear than stock, so it should take an impact with less damage.

Any other thoughts? I am leaning toward cutting a section out of the tank to make room for plastic sheets front and rear. The issues with the fuel cell other than maintenance/cost/rework are the available vertical space (fuel cell must have a firewall between it and the passenger per nhra therefore I would need to raise the trunk floor significantly), the loss of the spare tire (I can live with that), and filling from inside the trunk (have to move things to get to the gas cap during trips and introduce the possibility of spilling gas in the passenger compartment).

If I section the tank and reweld I will plan to tig or gas weld the seam to prevent introduction of a brittle mig bead (likely to crack on impact). I will also need to extend the filler neck (making sure its at least 4" inside the tank) and find a new grommet for the tank. 

Any other considerations I am failing to see? Thanks Turner and Cobra for your inputs.

Part of the recall kit on Pintos was a different (longer) filler neck that could flex more as fuel tank position got rearranged.

Filler in the truck is a PITA on trips.  Just saying.  Also doesn't really keep gas fumes out of the passenger compartment.  I'm sure you could make something work to get the outisde filler to fill a fuel cell.

I agree on not putting the fill in the cabin. It will stink even if it doesn't leak.

You might try a plastic tank out of something like a Ranger pickup, but mount it sideways instead of lengthwise. I have no idea about fitment, but could get you measurements from the '99 in my driveway.  I don't recall if the fill is on top or in the side, but the fuel pump is definately accessed from the top after tilting the bed up. Been there, done that.

I've seen folks build heavy gauge steel cans around plastic tanks too.

I don't know what to tell you about the spare...maybe get run flats?

I haven't carried a spare in any of my vehicles since 2001. Because (I'm stupid) reasons.

I am not too worried about the spare. I haven't carried one in this car yet (but I would like to add it if there is space). As far as the cell vs tank, I would rather use the stock tank unless there is a compelling safety reason to use a cell. Will a side fed cell with a rubber hose to connect to the filler, or a plastic tank actually be safer than the stock tank with plastic shields and the longer filler neck? (My car came with the longer filler neck and the plastic shield)

Thanks for all the input, I'll need to keep pondering this a bit

I had to get away from the fuel cell for awhile so the rear seat mounting got some attention. First a couple brackets to hold the studs in the right spot.

The whole seat assembly is moved about 1.5" forward from stock. The seat foam needed a bit of trimming to sit closer to flat. It will likely still need a bit of massaging. 

Personally,  I would skip the back seat and just carpet the area.  Maybe build a platform like the early Shelby Mustangs with storage under and spare on top. The Pinto is shaped more like a GT than an economy car anyway!

I've been following along because I've always wanted an IRS in my MII, and figured the Miata or XR4Ti were the best choices.  Miata wins because the width is right, and because Miata Is Always The Answer!

Having owned three Pintos, I can't imagine wanting to move the back seat forward at all.

Unless you need to carry children under the age of 5, I'd carpet it over too.

While removing the back seat would certainly simplify alot of things, and make room under the car, I've planned the project around keeping the rear seat fully functional and safe for passengers. Being able to seat 4 is alot of fun and was one of my criteria when I picked the pinto originally. If I wanted a 2 seater I might have started with a different/more capable car.

After much deliberation I decided to go with a 12 gallon fuel cell from JAZ. I had it delivered undrilled/unassembled so that I could relocate the filler/vent/pickup. Here is the can sitting in place:

Next up its time to make a cage to hold the cell. This also served as a project to get comfortable tig welding before some upcoming projects:

The next challenge was finding a remote style filler neck that would fit outside the strap grooves on the inner tank. JAZ was not able to give me a precise measurement of the flat area available, so I ordered and hoped I would be able to use a small filler neck from Tanks Inc as it had the smallest bolt circle I had found. Needless to say the flat area was too small. This necessitated a custom flanged fill neck. Here are the dimensions for anyone interested:

Cue multiple days in the shop:

This thick stainless loves to eat up tooling, so it was slow going with the somewhat dull tooling available. The welded section that adapts the tube to the flange will likely get redone as I am not satisfied with the weld quality, however it will work just fine for mock up:

Before plumbing or floors can be finalized the cell needs to be mounted. Priority was given to ground clearance (vs trunk space) due to the tons of drainage troughs in the roads here and anticipated ride height. 

Testing out the mounting concept:

Tabs added to the fuel cell cage:

After running around with an angle gauge and straight edge we have the mounts in:

The observant among you will notice the addition of a fuel level sender.

I did not use the "stock" cap that bolts through the inner tank and lid to locate the tank in the can. This necessitates a different locating feature so that the tank isn't sliding around in the can putting stress on the filler neck. I have a couple ideas but haven't settled on anything yet. The can is designed to be larger than the inner tank to allow it to  swell and expand. The locating features should be adequate to control the motion of the tank without creating excessive stress on the walls of the inner tank or increasing opportunity for puncture during a crash.

Next up I got stuck into making a filler neck. I had some scrap stainless tubing and decided to push my tig abilities a bit. Here is what I came up with:

First I got a cap/bung set, but didn't like how far the cap stuck out from the rear quarter. So, straight to the lathe. First the cap:

Then the bung to make a nicer geometry to weld to and to take some weight out of it:

Then transfer the welding wire template into tubing:

This thread is great, not sure how I missed this.  I have very fond memories of 3hr trips to camp in the back of my Grandpa's Poo-brown Pinto.  

Looks amazing on those nascar-style wheels too.  

Thanks golfduke, I appreciate the positive feedback.

Next steps for the filler neck:

During this time I went down a rabbit hole of trying different tig techniques and trying different fillers such as silicon bronze. Its about at this point I realized I'd gotten a little off track. I want to be driving this car soon and have some events at the end of the summer I would like to have the bean for. So, rather than cut the front end off, pursue the whole list of features I want for this car, acquire various new skills, and not be finished for 2 years, I will be getting the car back together and running in its current configuration and driving it a bit before starting on the next round of modifications. As you can see, this still requires significant fabrication. So keep following along

Totally still following along.

I really enjoy silicon-bronze TIG, and I use it for delicate things that HAVE to seal, like adding JIC/AN fittings to thinks so I can run them fancy hoses.