Yes, unfortunately people do dumber stuff on a daily basis. Everything "has" to have a warning label.

I have a basic idea, but I need to get the tank in it's exact spot before I can mock it up.

Good question. The psi of the pump doesn't matter because it's just transferring the fuel to the main tank. This pump is "free flow" rated at 100 gallons per hour, that means I can pump all 16 gallons of auxiliary fuel in less than 10 minutes. I've used variations of this pump for years to transfer fuel in the shops I have worked for and I've never seen a failure, they are super reliable.

That's where things get tricky. To transfer fuel between the two tanks (without removing both gas caps) there has to be a shared vent hose between the two tanks to equalize the pressure. But, when I'm driving around with the aux tank empty there will be an extra 16+ gallons of air volume in the fuel system, which will probably trigger evap codes. So in addition to the fuel on/off valve I also have to install a on/off valve for the vent hose, that will completely isolate the aux tank from the main tank while not transferring fuel. I plan on mounting both valves next to each other for quick and easy operation.

Here is the start of the upper supports for the aux fuel tank, it will be sandwiched like a Ford tank with HD straps below. You can also see the bracket for the fuel pump, I mounted it behind the tire to keep it protected from dropping off ledges and angry rocks.

Any plans for a skid plate or something to protect the tank from rocks, branches, etc.?

Thanks for the info. Carter has a good reputation for quality pumps.....I was just curious about the PSI.

I plan on having something, but I'm not sure what that will be yet. I really don't want a full 3/16" skid plate due to the extra weight. I'll figure something out, just need to get it in place first and go from there.

I got the second fuel tank support in place, so I was able to mock the tank in place and see how high I was able to get it. I was pleasantly surprised when I got it in place and took some measurements, it sets just a little over an inch below the frame rails. Once I get some real tank straps under it I should be right at an inch, you can't even see it when walking around the truck!

Any more thoughts on filler routing? I am about to give up on my aux tank idea as I cannot figure out a filler solution that I like.

Why not buy a filler neck with a cap and have a separate filler neck for the aux tank? Like this.
http://www.tanksinc.com/index.cfm/pa...rod/prd510.htm




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Yes, but where do you mount it.

@rkntoy Weld a tab on it and mount it to the same bolt that the factory filler neck bolts to. Should be pretty easy to do.

So the aux tank on my '74 F100 is done this way - fills through the wheel well!

Why not modify the filler for a Y? fill both tanks with factory fill tube?

@AssBurns - then where would it go? As this is for an aux tank I still need to fill my main tank.

@eimkeith - not a big fan of the wheelwell mount with all the dirt and mud kicking up there. Also it would end up being not much higher than the tank. The LC80 dual tank Y would be awesome but cheapest i found was $400. Living in Oregon a simple Y is a problem since the state says I am too dumb to fill my own gas tank without blowing up the gas station.

I should probably start my own thread and give @Dirtco back his