Big Fuel Tank

[george_tlc]

To answer the concerns re a gravity feed tank.

First, the chance of a spill from a split transfer hose is very small indeed, the OE system uses rubber and mild steel from the filler to the tank. ...

It's simple... In the US it is ILLEGAL to install an aux tank that gravity feeds fuel to another tank (certainly for the class of vehicle we're discussing in this thread and certainly for petrol).

If a person wants to ignore the law, then feel free to do so as long as you're willing to deal with any repercussions if something does go wrong at some point. I doubt your insurance company will come to your defense.

cheers,
george.

 

[scottryana]

So are; removing catalytic converters, tampering with EGR, bumper heights, tires sticking out past fenders, removal of mudflaps, no crumple zone bumpers, bumpers not designed for pedestrian impact, not venting through charcoal canister, dummy load O2 sensors, driving over the speed limit, etc, but you just like 90% of the people on this board have broken the law and done so willingly. I hate when people get all law high and mighty.

It's simple... In the US it is ILLEGAL to install an aux tank that gravity feeds fuel to another tank (certainly for the class of vehicle we're discussing in this thread and certainly for petrol).

If a person wants to ignore the law, then feel free to do so as long as you're willing to deal with any repercussions if something does go wrong at some point. I doubt your insurance company will come to your defense.

cheers,
george.

 

[george_tlc]

So are; removing catalytic converters, tampering with EGR, bumper heights, tires sticking out past fenders, removal of mudflaps, no crumple zone bumpers, bumpers not designed for pedestrian impact, etc, but you just like 90% of the people on this board have broken the law and done so willingly. I hate when people get all law high and mighty.

Seriously, in this case we're talking about a WHOLE bunch of fuel and installs that will be done by folk that may cut corners.

My POINT is that a failure of the fuel system plumbing could be a lot more catastrophic to you and others than a removed mudflap or EGR system or bumper etc.

I'm not that big all the stupid little laws, but in this case there's a pretty good reason to NOT gravity feed volatile fuels.

So as I wrote, FEEL FREE TO DO WHATEVER YOU WANT...

cheers,
george.

 

[scottryana]

Thanks for the permission george. I still haven't seen your case, a simple check valve can stop the main tank from emptying. Not rocket science, I agree don't strap a bunch of old milk jugs to your bumper and duct tape a garden hose to them, but this is obviously not what anyone here is talking about. (3) 5 gallon jerry cans on the bumper present more risk in a rear end collision than a well constructed double pass welded tank, that is between the frame rails and hidden behind a 3/16" metal bumper. Like I said before that is what makes mud nice you can get lots of different opinions. Now make sure you don't flip on those "off road only" lights when you are on a deserted highway.

Seriously, in this case we're talking about a WHOLE bunch of fuel and installs that will be done by folk that may cut corners.

My POINT is that a failure of the fuel system plumbing could be a lot more catastrophic to you and others than a removed mudflap or EGR system or bumper etc.

I'm not that big all the stupid little laws, but in this case there's a pretty good reason to NOT gravity feed volatile fuels.

So as I wrote, FEEL FREE TO DO WHATEVER YOU WANT...

cheers,
george.

 

[george_tlc]

Thanks for the permission george.

No worries, I gave it in the post that you took issue with as well

Some folk are not aware that it is illegal at least in the US (and for a good reason). Some folk aren't aware that a gravity fuel system can have serious failure modes if a hose fails, hose clamp lets go etc. I suppose none of us have had a PHH fail or other lines fail in our vehicles... I PRESUME if we have a thread in a public forum it would be a good idea to provide all the pros/cons for various options, maybe I'm mistaken.

Given that any subtank install involves a bunch of fabrication work to install, it seems counter intuitive to me why one would purposely engineer in the potential for a hard failure mode.

I installed my oem subtank many moons ago and was happy to have a fuel transfer system along with a solenoid valve (all oem) designed to prevent syphoning/gravity feed of fuel etc. The factory design was well thought out and implemented, I guess toyota doesn't want its customers to have a pinto experience.

cheers,
george.

 

[scottryana]

Well the pesky heater hose isn't really a fair comparison to a new fuel hose. The fuel hose won't be subject to 200+ degree external and internal temps, nor is a new fuel hose made out of natural rubber, like the PHH was 20 years ago. I plan on using a stainless steel braided teflon hose, will probably outlast the cruiser.

I feel perfectly confident that what I have planned as being a safe, long lasting, and well thought out, I will make you a deal though if it leaks and leaves me stranded I will make sure I come back here and update this thread, as long as you do the same if your transfer pump dies.

 

[george_tlc]

Well the pesky heater hose isn't really a fair comparison to a new fuel hose. The fuel hose won't be subject to 200+ degree external and internal temps, nor is a new fuel hose made out of natural rubber, like the PHH was 20 years ago.

I feel perfectly confident that what I have planned as being a safe, long lasting, and well thought out, I will make you a deal though if it leaks and leaves me stranded I will make sure I come back here and update this thread, as long as you do the same if your transfer pump dies.

Sounds good. Just keep your fire extinguisher handy

cheers,
george.

 

[scottryana]

nothing like a little fear mongering

 

[Dave 2000]

@ BigBoy/Akella

PM me a price for a dual filler and shipping to 30880 Spain please?

regards

Dave

 

[hoser]

With a gravity fed tank, are you more apt to saturate the vapor recovery system?

 

[scottryana]

You mean because of the additional pressure in the system? The second tank wouldn't be above the level of the canister. It is a possibility though, I think there would be additional load on the vapor recovery system from running 2 tanks into one canister as well, like the OEM aux tank system probably does. Good question.

With a gravity fed tank, are you more apt to saturate the vapor recovery system?

 

[Dave 2000]

With a gravity fed tank, are you more apt to saturate the vapor recovery system?

Not on euro diesels, unsure of the effect on the petrol versions.

regards

Dave

 

[Bearcat80]

The cheap way

This has been covered before, but with some homegrown ingenuity and junkyard measuring, a lot of stock tanks from other rigs can be made to work. See this link for a stellar example:

http://www.expeditionswest.com/equipment/tacoma/fuel_tank.html

I have measured several tanks and most of the late model jeep tanks should work, as well as the trooper tank in the thread. I think this could be done for $2-400 if you are willing to cut a quarter panel for the filler neck. I used to be opposed to this, but since my cruiser is worth 7k tops, who cares? It's next on my list after a regear.

 

[greentruck]

SNIP
I have done the trans labrador highway 2 years ago and it the place where you need at least additional 10gal for a stock lc and more than that for armored. PM me if you want some information on that trip.

As other place i want to check out is trans taiga road that is longer than trans labrador and it pure service road for Quebec hydro and on that one you need as much gas you can only bring.

Akella,
Thanks, will keep that in mind as we get closer to this trip. The Trans-Taiga sounds interesting, too. We'll probably have about 3 weeks. I've been putting this trip off as I struggle with my dissertation, but I'll have the draft done by the end of the this year -- finally -- then polish it up, defend, then both the wife and I are very much looking at getting out of here for a nice long road trip next spring.

What oem parts you guys think we will need if we will go for the custom sub tank? In my understanding we only need:

*OEM Dual filler neck
*OEM switch
*OEM overhead console(expensive and hard to get new)

Filler Neck -- Yes, a must have. You don't want any compromises in fueling
Switch -- Yes, clean install and looks right. Is this a spring-loaded switch, i.e. needs to be held down to keep power on? If not, then a switch that does this might be better (will explain in a moment)
Overhead console -- nice option, but I'd be thrilled just to have as an option a gauge somewhere else. If the main tank gauge could be hacked to read the aux on demand via another momentary switch, that would be slick. The install would be easier and cheaper without having to do the console, chop the visors, etc.

Here is what else might work best as a simplified install using OEM components as much as possible where they seem like the best solution. I read through the thread a couple of times, but I'm no expert, so my guesses on how to do this with some OEM parts could use feedback on what I'm missing or don't understand.

I reread a bit of things to familiarize myself as best possible with how Mr T does it. The OEM approach is to automate the process. What I think we're looking for are several ways to plumb things so to make the process manual. Some folks like gravity feed, but you and your insurance agent are on your own with that one. I can see people doing it, but I have my reasons not to. That seems to be more straightforward to plan, but I'll let someone take a hack at that. Here's I'm hoping to achieve a manual implementation of the OEM's automated system.

Citing elmariachi's list from this thread:
https://forum.ih8mud.com/80-series-tech/213266-oem-subtank-retrofit-install-project-pics.html

Here are things I think might be needed and can be substituted for or simply omitted from a manual feed control system (comments and suggestions invited):

Fuel transfer ECU , 89570-60110 No
Fuel transfer dash switch (momentary 7-pin), 84560-60020 Yes, I hope this fits my need for the spring-loaded manual switch, but needs verified
Female plug for dash switch, 90980-10801 Probably
Wires splices for dash switch(6) , 82998-12340Probably
Housing for kickpanel connection, 90980-10807 Maybe
Wire splices for kickpanel connector, 82998-12340 Maybe
Fuel system wiring harness (wire #2), 82182-60050 Maybe
Overhead console roof wire harness (w/moonroof), 82171-60241 Optional to me, others may want it, but elmariachi's thread will be useful on that
Fuel pump bracket, 23206-66030 Not sure
Fuel pump bracket gasket, 77169-60010 Not sure
Fuel pump in-tank filter, 23217-16490 Probably
Main tank level switch w/gasket, 83330-60040 Not sure
Screws for tank switch (6), 90159-A4010 Not sure
Large fuel hose (2), 77213-60090 Maybe
Large clamp (4), 90460-55030 Maybe
Small vent hose (2), 95311-13022 Maybe
Small clamp (4), 90467-20134 Maybe
Dual filler neck mounting bracket (1) 90119-08686 Yes
Fuel line gasket for banjo fitting (2), 90430-12026 Not sure
Fuel tank drain plug gaskets (2), 90430-12245 Not sure
Fuel door decal (1) 74572-60010 Yes

Subtank No, use US or Canada fabbed one
sender Probably
mounting straps (RH and LH), Used Depends on the fabbed tank, but I think would be good to use OEM mount points, even if different straps need to be made for the larger tank
Tank mounting bolts (4), 90129-08001 Depends on straps, as above
Dual filler neck, Used or new as option,
Transfer pump and solenoid assembly, Used Yes, I want to use this if the flow on the pump is sufficient to move gas, but pressure of holding switch helps keep your mind on getting that process done, If not, I'll list an option below.
Overhead console w/accessory meter, Used Optional
5/16" fuel hose As needed
Custom mounting ring for main fuel tank switch (available from El Mariachi) Not sure

I did look around some for how others do this in North America, Came up with a few links/potential parts sources, etc

http://www.aerotanks.com/vehicles/othertrucks.html
They still list a 55 gallon Aux for "72-82" Toyotas, presume for FJ40s? Notice they list some potentially useful parts lower down on the page.

They will also custom build tanks:
http://www.aerotanks.com/main/Products.html

It sounds like there is no return line to the OEM subtank, except in the diesel version. I presume that it's directly plumbed into the evap system. Apparently, the OEM system deals with any difference in pressures created when the subtank is pumped into the main. I presume if a custom subtank is plumbed the same that should work the same.

Beyond that and using the OEM filler, what I'd envision is that the OEM subtank fuel pump be used, that the momentary switch is wired to require button to be pushed constantly to stay on (OENM< if it'll work for this, otherwise something else with a good heavy spring to remind you to let off when things get full). I presume that you can watch the main tank gauge as you fill from the subtank, which is why I think a gauge for the subtank is just an option, not necessary. I could probably do fine without a subtank gauge, but I can see it being nice to have also, otherwise you're guess at what's left to a certain extent. Doing without any extra gauging does simplify things, too.

OK, long enough for now, some ideas on how it would work, so take soms shots at them. The tricky part will be getting the harness connections needed, while not letting the ones not needed when not doing the full OEM install get in the way.

 

[greentruck]

This has been covered before, but with some homegrown ingenuity and junkyard measuring, a lot of stock tanks from other rigs can be made to work. See this link for a stellar example:

http://www.expeditionswest.com/equipment/tacoma/fuel_tank.html

I have measured several tanks and most of the late model jeep tanks should work, as well as the trooper tank in the thread. I think this could be done for $2-400 if you are willing to cut a quarter panel for the filler neck. I used to be opposed to this, but since my cruiser is worth 7k tops, who cares? It's next on my list after a regear.

Of course, it will likely also work with the OEM dual filler neck for a cleaner install. I can see hacking a pickup truck fender, not so sure about the 80, where you're cutting into the passenger compartment when you make the cut to add an extra filler. But I think this thread has already demonstrated there's more than one way to skin this cat.

The linked article is excellent, pretty much what I'm looking for in how I want to set up mine. Thanks!

 

[1FZj80]

I agree with George, you do not want to gravity feed a Class I flammable liquid. Bad idea. No one would install such as system for any application, let alone a vehicle. Regardless of laws, it violates basic common sense regardling flammable liquids with low flash points (see YouTube). And if you do install such a system (and want to win a Darwin award), DO NOT use a open uncontrolled connection between the two tanks. Use mutilple safety shutoff valves that fail closed and only open during intended fuel transfer. Do not let the main tank float on the head of a tank located at a higher elevation, you need to control the flow and prevent the main tank from being pressurized.

 

[scottryana]

No one would do it? smh.

NW Metal Products does it:
http://www.nwmp.com/index.php?option=com_content&view=article&id=4&Itemid=4

Looks like lots of expedition forum guys are doing gravity tanks.

I appreciate the opinions, but any kind of assumption that it isn't common sense or you insinuating that I am a darwin award candidate, is nothing more than an abusive ad hominem attack.

I am still waiting for good reason. If I welded the two tanks together with a 3" tube and called them saddle tanks you would have no issue.

Again I agree there are right and wrong ways to do things and if I had an old gas tank from an El Dorado strapped to the roof and a rubber hose running down the outside of the truck to the main tank I might agree with the pressure difference, but we are talking a matter of inches. Sure hope you don't drive up or down anything steep so the front or back of the tank are inches higher.... seriously.

The second tank will not be above the charcoal canister, if you port the main tank halfway up the side, and run the hose from the bottom of a 6" deep gravity tank the top of the aux tank would be even with the top of the main tank, no pressurization.

I agree with George, you do not want to gravity feed a Class I flammable liquid. Bad idea. No one would install such as system for any application, let alone a vehicle. Regardless of laws, it violates basic common sense regardling flammable liquids with low flash points (see YouTube). And if you do install such a system (and want to win a Darwin award), DO NOT use a open uncontrolled connection between the two tanks. Use mutilple safety shutoff valves that fail closed and only open during intended fuel transfer. Do not let the main tank float on the head of a tank located at a higher elevation, you need to control the flow and prevent the main tank from being pressurized.

 

[Akella]

My opinion on:

Filler Neck -- It is essential part of subtank and we a so lucky to have this option for 80 and dont have to hack our body panels on LC. Still available new and can be sources used. Pre 95 design is much easier to work with as it needs regular flex hoses to the tanks instead of angled one for 95+ version

Switch -- switch is available in 2 types.
Non momentary for diesels as diesels use valves to change feed from tanks. Momentary for petrols as they use transfer method and controlled by ECU.
How i understand they easiest ways is to use momentary switch and George's ECU to control pump. George are you still making them?

Overhead console -- nice option but will be tricky to find the right sender for non oem tank to make it work accurately. correct me if am wrong.

OEM transfer pump ans valve -- still available new, but really pricey especially pump over $300, however, can be found used. If getting OEM transfer system you need to make sure that you are getting all the brackets as they are discontinued.
I personally wont go for OEM transfer system as i think it is not worth the headache of sourcing one when you can get one of Facet pumps with check valve and Anti-Siphon Valve builtin in to the pump, plus this pumps will be easy to control with George's ECU or any other controller board. However they are not fastest pumps i thing 20+GPH will be fine in mine sub tank set up. What you guys think?



I did look around some for how others do this in North America, Came up with a few links/potential parts sources, etc
http://www.aerotanks.com/vehicles/othertrucks.html
They still list a 55 gallon Aux for "72-82" Toyotas, presume for FJ40s? Notice they list some potentially useful parts lower down on the page.
They will also custom build tanks:
http://www.aerotanks.com/main/Products.html
Seems like a good source, but wee need blue prints in order to get it going, which is the hardest part.

It sounds like there is no return line to the OEM subtank, except in the diesel version. I presume that it's directly plumbed into the evap system. Apparently, the OEM system deals with any difference in pressures created when the subtank is pumped into the main. I presume if a custom subtank is plumbed the same that should work the same.
Sub Tank is ventilated through dual filler neck. 2 tanks are joined there.


OK, long enough for now, some ideas on how it would work, so take soms shots at them. The tricky part will be getting the harness connections needed, while not letting the ones not needed when not doing the full OEM install get in the way.
Harness wont be that hard, if using George's ECU.

This has been covered before, but with some homegrown ingenuity and junkyard measuring, a lot of stock tanks from other rigs can be made to work. See this link for a stellar example:

http://www.expeditionswest.com/equipment/tacoma/fuel_tank.html

I have measured several tanks and most of the late model jeep tanks should work, as well as the trooper tank in the thread. I think this could be done for $2-400 if you are willing to cut a quarter panel for the filler neck. I used to be opposed to this, but since my cruiser is worth 7k tops, who cares? It's next on my list after a regear.

That will be ideal and i think it can be done, however it will take a lot of effort and time to find proper tank to fit under rear of 80.

To bad he didnt post dimensions of the tank.

 

[1FZj80]

How i understand they easiest ways is to use momentary switch and George's ECU to control pump. George are you still making them?

A simple inexpensive control circuit for fuel transfer uses a flow switch and a relay/contactor. The momentary switch closes the contactor to start the fuel flow, the flow switch contacts close upon fuel flow and keep the pump on until flow stops and the tank is empty. When the tank is empty the contacts in the flow switch open and pump turns off. I've been using this setup for over 10 years without issue.

 

[Akella]

A simple inexpensive control circuit for fuel transfer uses a flow switch and a relay/contactor. The momentary switch closes the contactor to start the fuel flow, the flow switch contacts close upon fuel flow and keep the pump on until flow stops and the tank is empty. When the tank is empty the contacts in the flow switch open and pump turns off. I've been using this setup for over 10 years without issue.

That is good option too.