Any one done dual tanks with an EFI V8

[JoshT]

The 85 Ranger I just picked up for a cab swap on my V8 project, may just become the recepient of the V8 swap instead. Was going to build an 86 SWB street truck, but for reasons I needed/wanted to replace the cab. Bought this 85 Long Bed today with the intent of dropping the cab over the 86 frame and the 98 Explorer 5.0L currently sitting on it. The more I think about this "donor" truck, the more I lean towards it being a "recepient" and building it instead. Largely because my first vehcile was the 1984 Long bed in my sig, and how similar to that truck this 85 is. Same original interior and exterior color, silver on blue. Same configuration, regular cab, long bed, bench seat. Though 20 years apart, they were within 5 miles of the same location when I became the owner. The 84 was at my aunt's house in Americus GA when my grand mother gave it to me, this one was less than 5 miles away straight line distance.

Anyhow, the question is about fuel system. This 85 Ranger is a 2.3L dual tank truck. That means it's EFI and already has electric fuel pumps which is an advantage. Unfortunately, I doubt that the stock 2.3L fuel system is up to the task of feeding the 5.0L.

Anyone done this with a dual tank Ranger before? How did you handle it?

Looking at parts listing on Rock Auto it appears that the in tank pumps are probably lift pumps, and there is probably a secondary high pressure pump in line between the switching valve and the engine. I guess I could keep the lift pumps in tank, replace the in line pump with a high performance aftermarket pump? Like maybe a Walbro 255lph inline pump.

85 high pressure pump: 40gph/95psi
98 Explorer pump: 50gph/120psi
Walbro GSL394BX (aka 190lph): 50gph/87psi
Walbro GSL392BX (aka 255lph): 67gph/87psi <- common in-tank pump rating for 5.0L Mustang crowd
Something else?

If I did upgrade woutl the fuel lines and rest of the sustem support the 5.0L? I'm intentionally ignoring age related issues here.

Other option that I see is to upgrade the individual in tank pumps to something like the Walbro 255lph, which would be relitavely easy since it already has in tank pumps. The challenge then becomes how to plumb the rest of the system to match since I understand from AllanD's old posts that the switching valve is the weak link in the system. I'd have to come up with something custom with hoses and check valves to repalce all of that. I can see this being an interesting idea leading to a dual fuel setup, IE: regular and race gas with. That's pipe dreams for down the road with aftermarket EFI and a flex fuel sensor. Still, something like this seems like my other option for keeping dual tanks, and I'll probably eventually end up here regardless. Just not sure exactly how to go about it, and would prefer to keep a stock style fuel system for now if possible/practical.

 

[Angie]

IE: regular and race gas with. << if this is the reason for the whole experiment I would say why bother? What compression ratio would your engine be at to justify the high octane for race only fuel? and then be running lower octane in the engine? the knock and ping for lower grade in high performance engines will destroy it.

just my $0.02.... cheers

 

[Roert42]

I would be interested to see what you come up with if you make a custom selector valve.

Do both pumps run all the time on a stuck setup or is there some kind of handshake that happens when the switch gets changed


Wouldn’t want the pumps to switch on and off at the same time, would want a slight delay for the second pump turning off to keep from momentarily dropping pressure.

Either way I would probably go with high pressure in tank pumps and remove the in line pump. Less parts to fail.

 

[alwaysFlOoReD]

My RV has the same system; in tank lift pump and on frame high pressure pump. Afaik the pumps are the same from f350 down thru ranger. My RV is F350 base with a 460 efi. I think your stock high pressure pump will work fine.
And there are other tank switching systems from other manufacturers. I found one from I think a Chevy that worked for me.

 

[RonD]

The in tank "lift" pumps are fine to use with an external high pressure pump between tank switch and engine
1988 and older fuel level senders also use a different signal that 1989 and up Fords, just FYI, so you want to keep those

Unless you will be super or turbo charging the V8 it will have plenty of fuel at 40 or 60spi, which ever the V8 computer needs

30gph can do up to 300HP
40gph can do up to 400HP

The stock 2.3l fuel system was fine up to 300HP, but ran 40psi so if the V8 Computer you are using is set to expect 60psi then change the regulator setup to increase the pressure
High pressure pumps will go to 80+psi unregulated

The pressure is only an issue to the computer's preset fuel flow calculations which is the injector rating in pounds per hour at XX pressure

GPH flow is for horse power calculations

You can put in 50 or 60gph pumps but it just sends more fuel back to the tank on the return line, if its using one

 

[JoshT]

IE: regular and race gas with. << if this is the reason for the whole experiment I would say why bother? What compression ratio would your engine be at to justify the high octane for race only fuel? and then be running lower octane in the engine? the knock and ping for lower grade in high performance engines will destroy it.

You aren't wrong. I was kind of talking out my ass with race gas. I'm also taking way down the road there. Right now I'm running a stock Explorer 5.0L, but I don't intend to stay that way. I don;t know what future engine build will be like, that'll largely depend on what I think after driving it for a while. I do think that build will involve aftermarket EFI, and that could support a flex fuel sensor and tuning adjustments to account for the cotaine change.

Probably never happen, just an idea that popped into my head. Even if I did do dual fuel setup like that, I definitely wouldn;t need/want to be buying 13 gallons of that special fuel. If I stick with building the longbed, I would like to keep the dual tanks since I've got it even if it is just regular gas in both.

I would be interested to see what you come up with if you make a custom selector valve.

Do both pumps run all the time on a stuck setup or is there some kind of handshake that happens when the switch gets changed


Wouldn’t want the pumps to switch on and off at the same time, would want a slight delay for the second pump turning off to keep from momentarily dropping pressure.

Either way I would probably go with high pressure in tank pumps and remove the in line pump. Less parts to fail.

I have no idea. Don't even have the truck here yet. Bought it yesterday, but don't have the means to get it home at the moment. Truck, but no usable trailer and couldn't get a uhaul in time. I had it towed to my cousin's house about 10 miles from where I bought it, but that's about an hour away from me. Hopefully I'll get my trailer ready in the next few weeks, or dad's will be free to go get it home.

Mechanically I imagine it would involve t-ing the supply lines from each pump together, with a check valve for each pump to prevent flow from one tank into the other. For the teturn you;d need some sort of switching vave to make sure it returned to the right tank.

Electronically you'd need a switch that changed the sending unit between the two tanks and controlled the return valve. For the pumps, you are right about needing a little overlap while switching. That is something I hadn't thought about, but I think it could be handled with a time delay relay to keep it running for a few seconds after power is switched. Something kind of like a turbo timer setup, except for a fuel pump.

My RV has the same system; in tank lift pump and on frame high pressure pump. Afaik the pumps are the same from f350 down thru ranger. My RV is F350 base with a 460 efi. I think your stock high pressure pump will work fine.
And there are other tank switching systems from other manufacturers. I found one from I think a Chevy that worked for me.

I'm not too sure about that fuel system, just what I'm puzzling together from browsing rock auto catalog for the truck. That does sound promising.

I've seen aftermarket EFI systems in street driven track cars that use dual tanks. Pump gas for regular driving, and switch to smaller "race gas" tank for the track. They use some sort of switching valve and a flex fuel sensor so switch between the tanks and adjust tuning in the ECU. Never paid much attention to them because I didn't even have thoughts about a dual tank configuration until yesterday. I wouldn't need a flex fuel sensor if gas in both tanks is the same, wouldn't do anything with Explorer EFI anyway, but the rest wiohould be about the same. Knowing the proclivity of those EFI systems and racers to recycle Chevy parts, it was probably some Chevy valve that they are using for that.

The question if I go that way. Do I replace the in tank low pressure pumps with high pressure, and delete the in line pump? Or do I stick with the low pressure in tank pumps and high pressure inline pump, just changing the valve?

The in tank "lift" pumps are fine to use with an external high pressure pump between tank switch and engine
1988 and older fuel level senders also use a different signal that 1989 and up Fords, just FYI, so you want to keep those

Unless you will be super or turbo charging the V8 it will have plenty of fuel at 40 or 60spi, which ever the V8 computer needs

30gph can do up to 300HP
40gph can do up to 400HP

The stock 2.3l fuel system was fine up to 300HP, but ran 40psi so if the V8 Computer you are using is set to expect 60psi then change the regulator setup to increase the pressure
High pressure pumps will go to 80+psi unregulated

The pressure is only an issue to the computer's preset fuel flow calculations which is the injector rating in pounds per hour at XX pressure

GPH flow is for horse power calculations

You can put in 50 or 60gph pumps but it just sends more fuel back to the tank on the return line, if its using one

Not too worried about the low pressure pumps working, but I wasn't sure if the high pressure pump and feed lines would be adequate. Got no intents to remove or replace the fuel level senders. If the do have issue, I'll be replacing with stock replacement components.

For now the engine is a stock 98 Explorer 302 with headers, 1.7:1 roller rockers and upgraded springs. I expect a little better than the stock rated 215hp, but probably no up to 300hp. Down the road after an engine build I would expect to be in the 350+ hp range. I really can't see needing or wanting more than that in a first gen Ranger.

Pretty sure the Explorer EFI is expecting 60 or 65 PSI. I know the Explorer was return style and from what I can tell the ranger is too. The pressure regulator appears to be on the fuel rail for both, so that shouldn't be an issue.

I get that higher flow means more return, but I didn't know if the stock pump would provide enough flow to begin with.

 

[RonD]

The dual tank switch with 6 ports was also a reservoir/filter so high pressure pump wouldn't run dry, no delay is needed

It was just a canister filter which you can add between a simpler dual tank switch and high pressure pump as well so pump never runs dry

Problem with all high pressure pumps is that they have no suction, they can't PULL gas from the tank, which is why they need to be IN the bottom of the tank or have a low pressure pump feeding them

 

[JoshT]

The dual tank switch with 6 ports was also a reservoir/filter so high pressure pump wouldn't run dry, no delay is needed

I was wondering about that. Like I think I said, I wasn't planning to use the dual tanks when I was buying the truck, so I didn't even look at that. Truck is an hour away, or I'd go out and look at it now. That was kind of what I was thinking about the stock setup, there was probably a filter/reservior that held enough to feed the high pressure pump while switching tanks.

Did you possibly mean:

It was just a canister filter, which you can add between a simpler dual tank switch and high pressure pump as well so pump never runs dry

I was wondering if possibly using a large inline fuel fiter might provide enough reservior for switching the tanks. Assuming that the factory reservior/valve combo were to fail, I'd probably look at something like this to replace them.

Holley EFI 534-39 Dual Tank Fuel Pump Kit

Dual Tank Fuel Pump Switching Valve Kit. Includes switching valve, relay, switch, and harness

www.holley.com

Obviously, I would just be after the valve since I've already got control switch and pump. I think I've seen the valve referenced as a Pollack 42-159 or 42-300P (same with harness and switch?) 6 Port Fuel Selector Valve. I guess the low pressure pumps provide a lot of flow but not pressure, so they can get fuel up to the high pressure pump pretty quickly once energized. So that valve and large inline filter would probably work to replace the factory valve and reservior?

Would the low pressure pumps in the tanks only be running when that tank is selected, or would they both need to be on full time? If the latter, I assume that the selector valve would need to bypass the unselected tank back into that tank's return line so fuel would circulate and the pump isn't dead headed.

Problem with all high pressure pumps is that they have no suction, they can't PULL gas from the tank, which is why they need to be IN the bottom of the tank or have a low pressure pump feeding them

Yep, I'm familiar with in-line high pressure pumps. Running one on my F-100, it's lower than the bottom of the tank and gravity fed by the tank. If I could, I'd run either a low pressure pump in the tank or feeding it, or put a high pressure pump in the tank. Unfortunately there's no real way to do either with the stock style tank in that thing.

Not even thinking about removing the low pressure pumps in the tanks on this Ranger as long as I've got a working high pressure pump in line. The only way I'd change that is if I completely removed the inline high pressure pump, then replaced the in-tank low pressure pumps with high pressure pumps feeding into the selector valve. That's not something I'm going to do unless I really needed to overhaul the entire fuel system.