EFI power surge for stock tanks

[th3fourn]

Hey everyone,

I have a 1974 Bronco and I am keeping the stock fuel tanks but the guy working on my 302 engine told me about Robb Mc Performance that has a high performance small fuel system that can be used with stock tanks, you just have to mount it and have a return line.
- That being said I have 2 fuel tanks so wondering how that would work as well as has anyone done this?

- Will I need another mechanical switch for the return line as well?

If anyone has done this or has any info I would greatly appreciate it.

Here is the link http://robbmcperformance.com/products/powersurge.html

Respectfully,

Brett

 

[Rustytruck]

The easiest way is to plumb it to the main tank. so it fills and recirculates there then plumb your auxiliary tank with a remote electric transfer pump to pump the aux tank to the main tank. then you can get rid of the switch under the seat. that way you drive until the rear tank gets low and hit your transfer pump to transfer the aux fuel to the main. this is simple but not fool proof if you want to run down the aux tank only you cant. if you try to pump from the aux to the main tank and the tank is not empty enough you will have a problem with over filling. just have to pay attention and a protected pump switch so accidents don't happen. its the return line that complicates things. there are much more work around but each level has its own complications and expenses.

 

[Timmy390]

While I've not used it I like this option.
https://bcbroncos.com/shop/fuel/fue...l-selector-valve-efi-6-port-for-early-bronco/

Run a single E2000 external pump and use the fill neck vents to plumb in the returns. Wire the 6-way to a rocker on the dash or wherever and get rid of the stock selector.

I run a single tank as my aux has a hole but plan to use the 6-way at some point. I use an E2000 external already.

Tim

 

[bratengj]

I'm in the process of doing this myself with a pump/reservoir unit mounted in the engine bay for my new FiTech. On mine, I replaced the original three port fuel selector valve with a six port (I think it was made by GROCO and used for boats). That way it returns fuel to the same tank it's pulling from. The new return line goes from my pump/reservoir back to the valve which redistributes it to the tank it's pulling from. To return the fuel to the tank I ran a 3/8" line from each of the return ports on the valve to each of the tank's 5/8" hoses connected to the filler neck's breather tubes. I cut the 5/8" hose, added a 3/8" X 5/8" hose barbed "T" and connected the new 3/8" lines, so the fuel will return to each tank via the breather tubes on the filler necks.

 

[Spaggyroe]

I have a Holly Sniper in-tank retrofit pump in my stock rear tank.

I'm in the process of adding the aux tank, plumbed as a transfer tank as @Rustytruck mentioned above. If you plumb your vent line from the main tank to the aux tank, you can (hopefully) prevent any accidental over-fills of the main tank.

I'm also working on a circuit board that will cut power to the aux tank fuel pump when the fuel level gets very low. I've known people with similar systems that have burned up their electric fuel pumps by accidentally leaving them on after running the aux tank to empty.

 

[th3fourn]

Hey I love this idea, I'm thinking about doing this, any idea on what type of pump or switch you would recommend? Also would you wire this to a switch to where the pump transfer switch would be? Any recommendations Id appreciate it

 

[th3fourn]

Braten, I get what your saying but I just cant picture it. I bought the 6 way selector but still having trouble imagining how this would be plumbed. If you have any pictures or diagrams I would appreciate it.
Thanks,

Brett

 

[MarsChariot]

This may help. It is a simple diagram that I put together for myself when I was wiring my Pollack vale and plumbing my fuel lines. You can use the stock switch.

 

[EricLar80]

All of this sounds complicated. What problem are you actually trying to solve that is worth potentially creating 5 more for?

 

[MarsChariot]

All of this sounds complicated. What problem are you actually trying to solve that is worth potentially creating 5 more for?

Well, Idon't know, but if you have to ask......

 

[DirtDonk]

What problem are you actually trying to solve...

Installing in-tank electric pumps in both stock tanks, including return lines to each.

Paul

 

[EricLar80]

Well, Idon't know, but if you have to ask......

I get the electrical circuit. I’m asking about the extra tank thing and it’s purpose. My point is that it sounds like this system will have 3 pumps and countless fittings. Lots of opportunity for something not to work correctly.

 

[lars]

If you want simple, as in no added electrical parts, 6 port manual valves are available. In which case you can keep the stock (or what ever you have) fuel level senders and use a frame-mounted high pressure pump.

After going through a couple of Pollak 6 port valves I installed one of these in the OEM fuel valve location since I got one for a bargain price in the course of my job:
http://www.andair.co.uk/product/duplex-fuel-selector-fs2020-d2/

Another option, less expensive and could probably made to fit in the stock location:
https://www.groco.net/products/valves-seacocks/fuel-valves/fv-6-port-series/fv-65038

Edit: just saw that bratengj above mentioned the Groco valve. Cool.

 

[DirtDonk]

Only two pumps if you keep it stock-ish. Three if you decide to go with the transfer pump and run the engine only from the main tank.
The auxiliary reservoir and pump are not needed for a carburetor, but if you're going to EFI that uses a high-pressure pump and want to keep the stock tanks and sending units, the reservoir is not a bad idea. No matter what, you are adding lots of stuff to accommodate the EFI setup, and retaining the stock tanks just limits your options.

There have been problems with some brands that seem to be due to the pumps running hot, but those also seem to be the ones that chose not to run a return line. Mandating the return line (rather than leaving it as an option) seems to have cured the FiTech issues, but there have not been a lot of sales of it after the initial offering either. So it's hard to tell if it was cured, or just that nobody is using it anymore!
I'd think the return lines cured the issue though.

But you're right. Still a lot of falafel to add to the vehicle, with lots of junctions that can leak. But with EFI and stock tanks you need a high pressure pump and you need a return line to both tanks. So you're kind of stuck trying to figure out the plumbing issues that crop up and coming up with various solutions.
Most of which are not easy using the stock auxiliary tank.

Seems like an electric switching valve between the two tanks and the stock low-pressure mechanical pump, then the new sump and pump, then the return lines to the switching valve, would be what you need.
Then you get to decide how you want to attach the return lines to the tanks after the valve.
This came up during that video linked above and is a fairly clever arrangement and one possible option: https://www.youtube.com/watch?v=W_swURooqVQ&list=TLPQMTcwNjIwMjHAlBJCrLT-BA&index=2 The "riv-nut" of fluid fittings.
Lots of ways to skin that cat though, so just one of many.

Paul

 

[lars]

Another tidbit.

I ran a stock aux tank for 20 years and 100k+ miles using Ford EFI. Thus I needed a return line (main tank was/is a NWMP 23 gallon tank that has a built in return).

I got some thin wall stainless steel tubing, 5/16" OD. Bored a hole through the stock sender cover plate near the supply line, then silver soldered a piece of the tube into it after bending it to the shape I wanted. Supported the new tube with a hose clamp to the old. Never had an issue with it. Only reason I replaced it recently was for more fuel capacity, valuable for the way I use my thirsty Bronco.

 

[Broncobowsher]

Remove the aux tank, install a 23 gallon main tank, don't mess with the dual tank BS.
That is the easiest way.

 

[th3fourn]

Thanks.

Thank you all for the input, I also was wondering do I have to have a certain diameter return line or is it ok to have a smaller diameter, my tank has two little I let’s where I believe before was a breather. Do I still need a breather or can it run without one.

Thanks,

Brett

 

[EricLar80]

Thank you all for the input, I also was wondering do I have to have a certain diameter return line or is it ok to have a smaller diameter, my tank has two little I let’s where I believe before was a breather. Do I still need a breather or can it run without one.

Thanks,

Brett

You should have a charcoal canister, not a breather per se, and you need one. Some get by without because their gas cap doesn’t hold any pressure.

You want the the return line to have “zero” pressure head so that pressure at the engine is correct. I wouldn’t recommend smaller but it may work if you don’t have a super high volume pump and the smaller section is not very long.

 

[th3fourn]

Thanks a ton, I believe with this surge tank you don't need the pumps in the rear that should be taken care by the pump up front. All I need to do per the supplier is make sure the return goes back to the tanks.

Thanks again,

Brett