auxiliary fuel tank?

[luke]

@ AllanD
wow, thanks for all the info! i think you've convinced me on the plastic f350 fuel tank. i think its the same tank ford used in many of their bigger trucks, shouldn't be to hard to find right?
the way i was planing to set it up was use either the existing fuel pump or maybe a higher flow pump from the new tank to pump fuel to the main tank via activation of a switch. i would install another gauge in the cab for the extra tank as well. from my understanding most stock fuel pumps only have a flow rate of around 50 GPH or something like that, then I'd have to take bends in the pipe and resistance into consideration as well. i'll have to look more in to that. but if i can flip a switch and refill my tank in about 20 minutes wile im driving i'd be ok with that. im sure going to have to do a lot of tinkering around and research to do this successfully! i appreciate all the info and ideas.

 

[doorgunner]

Don't sweat the details (except for what he said about pumping too much fuel/pressure into the main tank by accident.....BOOOOOM!)

let's say the new aux tank only sends 20gph to the main tank.

At 10mpg......you'd use 6 gallons of fuel in an hour.


I think no matter how many "bends" you need in the fuel line--you're still safe from sucking the main tank dry--even if you wait until the main fuel gauge hits "PLUM EMPTY"







now....on the other hand....if you installed a 2nd engine to go with the 2nd tank.....you'd only have 13 gallons of spare fuel per hour....just saying.....

 

[luke]

Don't sweat the details (except for what he said about pumping too much fuel/pressure into the main tank by accident.....BOOOOOM!)
let's say the new aux tank only sends 20gph to the main tank.
At 10mpg......you'd use 6 gallons of fuel in an hour.[/

yeah, im probably over thinking this lol, as long as tank 2 can pump at least the amount of fuel tank 1 is consuming i should be good.

 

[AllanD]

Could probably get a bunch of parts from a 90's f150 with dual tanks. Just make
sure the valving has the cross feeding recall already done.

The EFI F-series tank selector comes in two "flavors" the early one used up to 1990 or '92 is a "passive device"
power is switched between the low pressure in-tank pumps and the pressure from the pump acts on a detented
diaphram actuated valve that controls both pressure and return fuel flow direction.

thes are prone to failures that result in crossfeed incidents when the diaphram
tears and fuel can leak between the pressure side systems, because the in-line check valve in the low pressure
fuel pump is more of a sick joke than a "valve".

But it doesn't matter because this diaphram selector valve is bulky and literally too tall to fit inside the ranger
frame rails, as it is intended to mount on the
F-Series.

The later selector system used 91-92 up doesn't use ANY "selector valve" at all

Instead there is simply a Y-union in the metal fuel lines. on the pressure and return sides.
How do they control "crossfeed"? there is gets complicated...

Inside the cannister unit in the tank that actually houses the High-pressure pump there is
a pressure driven shuttle valve, when the pump is running
it opens the spring loaded valve that allows fuel back into the cannister
(where the fuel is run through a venturi that draws fuel up from the tank into the cannister)

Theoretically this setup should work... and you can probably guess from the way I'm saying
this that it doesn't work quite the way they intended...

Because the two pressure pumps are "open" to each other and the built-in
check valves are less than reliable... so the operating high pressure pump tends to blow
fuel past the outlet port check valve of the non-active pump... Oops!

What ford did to correct this problem was to retrofit an inline check valve external to the
tank unit to positively stop this undesired fuel flow.

that all being said the system that is closest to that used on Rangers is the system used
on econolines with dual tanks BEFORE ford switched to high pressure in-tank pumps...
Econolines in the late 80's used the same electrically driven six-port selector valves.

If you have a choice get a selector valve with the electrical connector from a 1988-90 these
use a better electrical connector. (but otherwise the valve is the same)

@ AllanD
wow, thanks for all the info! i think you've convinced me on the plastic f350 fuel tank. i think
its the same tank ford used in many of their bigger trucks, shouldn't be to hard to find right?
the way i was planing to set it up was use either the existing fuel pump or maybe a higher flow
pump from the new tank to pump fuel to the main tank via activation of a switch. i would install
another gauge in the cab for the extra tank as well. from my understanding most stock fuel pumps
only have a flow rate of around 50 GPH or something like that, then I'd have to take bends in the
pipe and resistance into consideration as well. i'll have to look more in to that. but if i can flip a
switch and refill my tank in about 20 minutes wile im driving i'd be ok with that. im sure going
to have to do a lot of tinkering around and research to do this successfully! i appreciate all the
info and ideas.

The one issue I had with the F350/450 plastic tank is that I had to assemble a fuel filler assembly
for it from pieces

The main rubber hose came with the tank off the DIESEL F350 donor vehicle.

The "vapor return line" (3/4" ID off a port on the top of the tank) is 3/4" bulk hose

And the metal part of the filler is a collage of parts made from the housing of the fuel filler
assembly off an Explorer that I disassembled (It is "soft soldered" together) and soldered to
the mounting flange of a Ranger filler assembly this way it would connect to the different
sized filler lines used on the F-350/450 tank but still mount correctly to the filler door
"pocket" in the bed side

Fun, Fun, Fun....

What will be really fun is what I'm doing next will be more fun...

My next project is making a LONG bed supercab on a 2001 frame.
I want the long bed because I have a 40gallon tank that I THINK I can
mount behind the axle... (I also have a 90gallon tank that I KNOW I
can fit against the head gate in the front of the bed.)

My big secret is that I can get "recovered" gasoline from a local junkyard at roughly half price
and the more I can save up and take with me the farther I can go.

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