100 series factory Aux tank

[rusty_tlc]

I found a factory 100 series aux tank for a reasonable price. :wings:

Now comes the fun part, how do I make it work with a minimal investment of time and money. Since I'm not a slave to the oem installation concept there is likely to be a transfer pump*. I plan to put the controls for it as well as a fuel gauge inside one of the rear quarter panel storage areas or center console. I plan to use the tank as a way to transport extra fuel with out using cans rather than something I can switch to "On the fly." Fuel transfer would probably happen while the truck is stationary.

It looks like a dual filler neck will cost more than I paid for the tank so I'm trying to come up with alternative ideas for filling it. I'm open to any and all ideas short of cutting hole in the quarter panel.


*The tank is suppose to have an internal fuel pump, I haven't verified this. Anyway, I'm not sure it would have a GPM rating that would make transfer feasible.

 

[adrenaline503]

Ummmm... no dual filler neck and no hole in the quarter panel.... Ummm... hole in the cargo area? Fill the main tank, transfer it to the second tank then refill the main tank? Do they make pumps that pump both ways? Just reverse the polarity?

 

[BiG BoB]

Simplest option I can forsee would be the pump out the main tank option...

Even if you're not planning to run off your aux tank, its worthwhile making sure you can re-plumb to it should you ever get a hole whilst out in the sticks.

Sean

 

[hoser]

Try sourcing a dual filler neck from one of the Frontrunner vendors. It would be much cheaper than OEM.

 

[rusty_tlc]

Try sourcing a dual filler neck from one of the Frontrunner vendors. It would be much cheaper than OEM.

As far as I can find out none are available at this time. However the price Paul quoted sounded in the realm of possibility for my budget.

 

[rusty_tlc]

Ummmm... no dual filler neck and no hole in the quarter panel.... Ummm... hole in the cargo area? Fill the main tank, transfer it to the second tank then refill the main tank? Do they make pumps that pump both ways? Just reverse the polarity?

A small trap door with the filler cap outside the body isn't out of the question.
The problem I see with the bi directional fuel transfer is the pick-up in the main tank. I'm trying to make as few mods as possible to thefactory fuel system.

Simplest option I can forsee would be the pump out the main tank option...

Even if you're not planning to run off your aux tank, its worthwhile making sure you can re-plumb to it should you ever get a hole whilst out in the sticks.

Sean

Good thought, since the aux tank (allegedly) has a factory fuel pump in place it shouldn't be to hard to noodle out how to kludge it in, then I can make sure I have the necessary supplies to do it. This also makes a good argument for a bi directional fuel transfer system, if the main tank fuel pump dies I could transfer fuel into the aux and use it's fuel pump.

 

[roscoFJ73]

I believe Bosch make fuel switching solenoids suitable for this purpose.

Try getting a dual filler from an Aussie wrecker,I dont think it will be extortionate.

 

[alia176]

*The tank is suppose to have an internal fuel pump, I haven't verified this. Anyway, I'm not sure it would have a GPM rating that would make transfer feasible.

Hmm, wonder why are you thinking it doesn't enough flow, just curious. The in tank fuel pump is rated for a high pressure fuel injection system, say around 50 psi nominal although I don't know what the flow rate would be. Are you suspecting that the gpm is that slow? Say, if the current pump delivers at 13 gph would that really be a big issue? You can transfer the entire tank in an hour while you're tooling around.

Anyway, just curious :coffeedrink:

 

[rusty_tlc]

Hmm, wonder why are you thinking it doesn't enough flow, just curious. The in tank fuel pump is rated for a high pressure fuel injection system, say around 50 psi nominal although I don't know what the flow rate would be. Are you suspecting that the gpm is that slow? Say, if the current pump delivers at 13 gph would that really be a big issue? You can transfer the entire tank in an hour while you're tooling around.

Anyway, just curious :coffeedrink:

Let me talk through this out loud.
Is 13 gph realistic?
Assume 10 MPG and 60 MPH that would equate to 6 GPH no?
Do you think the pump is capable of double that?
Moot point any way, as you say I could transfer while I drive at a rate at least equal to consumption. No telling how long the pump would last running unrestricted though.

For a bi directional transfer pump I'd like to be able to fill the Aux from the main tank in around 10 or 15 minutes MAX. With my attention span any longer and I'd be overfilling.:elkgrin: I guess I could set up a cut off circuit triggered by the fuel gauge, just use a comparator and a transistor to switch a relay. Kind of violates my KISS mantra for this project though.

 

[AndrewP]

I would get a factory filler. If you do anything else, your mod will become a pain in the ***. An Australian wrecker sounds like your best bet.

You could use the 80 series style control electronics from George Scolaro and I can send you the part number for a fuel pump that not only works great as a transfer pump, but is cheap as well.

I'd vote you keep is simple. Don't try and transfer two directions. It's a great mod and can change how you use your Cruiser.

 

[UK4X4]

My nissan has dual factory tanks and all the LC's here have the sub tank

Both tanks are filled seperately

there is a dual tank gauge on the dash and a sub tank button

On pressing the sub tank button the reserve transfers into the main tank

I tend to think mines a gravity feed into the main tank, as you don't hear any pumps operating

However I've not been lying under the truck when I push the button !

Both tanks to fill takes 120 ltrs of fuel

but with the thirsty straight 6 it still does not get you very far

and the weight has trashed the rear spring on that side as I always fill both.

Locally you could pick up all the relevant parts from the local scrap yard.......it just takes time and money

 

[rusty_tlc]

I would get a factory filler. If you do anything else, your mod will become a pain in the ***. An Australian wrecker sounds like your best bet.

You could use the 80 series style control electronics from George Scolaro and I can send you the part number for a fuel pump that not only works great as a transfer pump, but is cheap as well.

I'd vote you keep is simple. Don't try and transfer two directions. It's a great mod and can change how you use your Cruiser.

Are there two OEM styles?
I've seen pictures of the "Y" type and the "flapper" type.

 

[hoser]

Yes, like you said, there are two styles.

Let me talk through this out loud.
Is 13 gph realistic?
Assume 10 MPG and 60 MPH that would equate to 6 GPH no?
Do you think the pump is capable of double that?

Fuel pumps flow much faster than 6GPH. The excess fuel just returns via a return line back to the tank. So your fuel is constantly going back and forth from the tank to the fuel rail/regulator and back to the tank. Most fuel pumps range from 30-100 gph. My cheapy fuel pump can transfer my 24 gallon tank in about 1/2 hr.

 

[24HOURSOFNEVADA]

Kick down the intel...Do they have any more tanks?

 

[rusty_tlc]

Yes, like you said, there are two styles.



Fuel pumps flow much faster than 6GPH. The excess fuel just returns via a return line back to the tank. So your fuel is constantly going back and forth from the tank to the fuel rail/regulator and back to the tank. Most fuel pumps range from 30-100 gph. My cheapy fuel pump can transfer my 24 gallon tank in about 1/2 hr.

So my base assumption was wrong, I really don't have much knowledge about injected systems. Thanks for the correction.

Kick down the intel...Do they have any more tanks?

Sorry the seller only had two, an 80 and a 100. Both are gone now.