FUEL CELL INSTALL

[josephg]

There is a lot scattered info about this install so I thought I would do a write up and make it easy for anybody who wants do this.

Here is the stock truck floor in my 77 280

I started with a sawzaw and cut out the spare tire well

 

You need to use a long blade to get through the supports around the front and sides of the tire well

 

Then I used an angle grinder with a cutting blade for the detail work

 

Cut about 1/4-1/2" away from the frame rails in the front and the sides and about 2 inches from the rear this will make it easier to fabricate the sheet metal later

 

be sure to leave 2' from the rear of the car as there is sealant back there that is difficult to remove and can make it difficult to weld

 

next get some steel I used 16 gauge 1 1/4" square tube

 

here is a tip when you buy steel never ask the supplier to cut it to length, I git 12' for $12 but it would have cost twice that if I asked them to cut it even once

 

depending on what fuel cell you use the detentions will be different, I opted for the cheepo summit 16 gal plastic fuel cell (not scca approved but I dont plan on racing my Z)

 

These cells are more of a replacement tank than a true fuel cell but it works for my application

 

To match the curved portion of the frame rails I determined were I wanted the support and then measured that space at the point were my support would be widest then used a file to match the radius

 

 

I welded in the front support first and base all the other dimensions off its position be sure everything is square because it will look terrible if its not

 

 

I wanted the ports on the bottom of the cell to stick out just barely

 

 

Next I made a template out of cardboard I used some card stock from staples that had 1" graph lines printed on it which was nice

 

I used an angle grinder with a cutting wheel to cut the 18 gauge steel, The trick with this is try not to cut it in one pass just graze the surface and go through on the second or third pass

 

 

it fit really well on the first try... I would rather be lucky than good any day

 

when welding the seams only weld about an inch at a time and move around a lot to prevent head distortion, This was a lot of welding thought I would never finish

 

Be sure to use plenty of silicone on the seams to prevent rust and use a good quality primer on everything else

 

I will add plumbing the cell when I get to that point

[hoov100]

No offense, I'm not here to talk smack about your work. But that is probably one of the worst ways to mount a cell, in a car, not only will it not pass tech at a sanctioning body, but it very dangerous. It lacks a sheet metal body around the cell, grounding strap and structural support. Also there is nothing to protect the tank from road debris or if the car bottoms out.

 

A correct fuel cell install requires, a 1" steel square tubing cage built around the cell and welded to the frame, a sheet metal box around the plastic cell and a grounding strap. If you plan on using the factory filler neck, a one way check valve at the cell is HIGHLY recommended.

Edited March 6, 2010 by hoov100

[josephg]

No offense, I'm not here to talk smack about your work. But that is probably one of the worst ways to mount a cell, in a car, not only will it not pass tech at a sanctioning body, but it very dangerous. It lacks a sheet metal body around the cell, grounding strap and structural support. Also there is nothing to protect the tank from road debris or if the car bottoms out.

 

A correct fuel cell install requires, a 1" steel square tubing cage built around the cell and welded to the frame, a sheet metal box around the plastic cell and a grounding strap. If you plan on using the factory filler neck, a one way check valve at the cell is HIGHLY recommended.

 

Those are all valid points... however as I mentioned this is not technically a fuel cell it is a fuel tank the difference being the lack of a metal cage.

 

Many new car use plastic fuel tanks that are exposed in the same way. As far as bottoming out. the rear differential sits lower than the bottom of the tank. I will not be using the stock filler neck however, when I install the breather I will use a roll-over valve.

 

A few other people have done this the same way, I simply condensed the information. I personally think its plenty safe. I respect your opinion but for my application (not racing) I am satisfied with what I have

 

If anyone wanted to add the safety features discussed above my first suggestion would be to buy an actual fuel cell it cost a little more however if you are going to be racing its a must. Adding the 1" cage is fairly self explanatory. Its a little more work but if your racing or just want the extra piece of mind it might be worth it to you

[RB26powered74zcar]

Nice job. I like the good fit on the trim out.

[piston]

everytime someone builds something all the tech officials have something to say! lol.

 

nice job. clean and basic. although you could of add more tubes to support the tank for insurance, it should hold anyways.

 

even though if the car bottoms out, it will not hit the ground. im sure noone here mounts there cell/fuel tank lower than the differential.

 

josephg is correct, as big and low as the newer chevy trucks are, it also uses a plastic tank so i dont see why it is dangerous.

[hoov100]

<br>everytime someone builds something all the tech officials have something to say! lol.<br><br>nice job. clean and basic. although you could of add more tubes to support the tank for insurance, it should hold anyways. <br><br>even though if the car bottoms out, it will not hit the ground. im sure noone here mounts there cell/fuel tank lower than the differential. <br><br>josephg is correct, as big and low as the newer chevy trucks are, it also uses a plastic tank so i dont see why it is dangerous.<br>

<br><br>When you see your buddy's car hit the wall in turn three and catch on fire, you'll understand my point. The point I'm trying to make about the plastic tank exposed, is that; that plastic is not the same plastic, nor the same thickness as the ones used in car, the ones in cars are made the flex and deform in a crash without cracking. Also most of them from factory have a skid plate, or are way up in the frame.<br><br>Also with only those two straps and four 1/4 inch bolts holding it in place, that plastic cell will deform under loads and crack, assuming the bolts don't break first. Lets also not forget about rear ends and car crashes. Since the vehicle is going to be driven on the street, what is going to happen if you get rear ended at a light or in traffic? One last thing to point out, is the lack of heat shielding for the exhaust, those plastic tanks are very sensitive to temperature and are very thin, especially when they get old.<br><br>Nobody is bagging on your work, but that fuel cell is dangerous the way it currently sits, we/I ***** about it, because we/I care about your safety.<br> Edited March 7, 2010 by hoov100

[Oddmanout84]

Thanks Josephg for the writeup, and thanks Hoov for adding clarification on the sanctioned (right) way to install these. I've been considering doing the same thing to my Z, as the current tank has gotten pretty rusty and I don't know if the local rad shop will be able to fix it. That and I'm trying to replace all the soft lines with AN, so it should make sense. My only questions would be where to attach the grounding strap (one of the filler bolts?) to the body and how I'd build the sheet around the body of the cell where the outlet fuel feed fittings are. AN through bulkhead fittings? I'd be afraid that stress over time with any sort of chassis flex would cause the fittings to crack the plastic around where they enter the cell. Also, is there any regulation to the thickness of the sheet that is used to make the box?

 

Edit: Also, has anyone heard anything about the internal safety foam that Summit/RCI uses in their fuel cells breaking down over time with pump gas (and the occasional fuel treatment i.e. STP injector cleaner)? I heard an interesting thing on another forum that some offroad racing guys like to use wiffle balls since they don't get eaten by the fuel.

Edited April 14, 2010 by Oddmanout84