Simple fuel systems

I was discussing the other day the complexity of the fuel systems when using twin tanks and fuel inection. Interestingly an Aeromotive agent suggested using only one pump for all.
Having thoughts would it not be much simpler, less time consuming,cheaper and reducing the amount of pipework running in what's already a reduced working area.
What do you think.... pro's and con's ?
Two tanks but only using one with the second tank as storage.
Tank 2 ( drivers side ) full of fuel with a small flow sized pump, nrv and filter. Switched on only when needed to top up the first tank. Simple -6 hose from tank 2 to tank 1.

Tank 1 an Aeromotive A1000 h.p. pump mounted anywhere as it can easily suck sufficient fuel from the tank with an nrv and course filter between the tank and the pump.
This directly feeds to a swirl pot, another fine filter and straight to the injectors.
The fuel regulator has a single return to the swirl pot and thereafter return to the no 1 tank.
Circulating fuel through tank 1 only.
No solenoids, no low pressure fuel pumps, less hoses, less cost, more space


What say you ?
 
You'd have to run the cross line against the back of the bulkhead, as running it throug the cabin would create more potential IVA issues than to shake a stick at I guess. That area is already tight Keith as you noted.

Interested why you primary feed on the passenger side not the drivers? I would have thought it would be better on the weight distribution in general to keep the passengers side as full as possible, otherwise you would have in general more weight on the drivers side (you + fuel); or have I had too much coffee this morning?

I personally have no such luxury (if I ever get back to the build again), as I am running a Holley 670cfm Street Avenger. Mine will just be two simple Carter pumps mounted int he sills and a changeover solenoid.
 

Ian Anderson

Lifetime Supporter
Keith
It will not work.
The long thin tanks will allow fuel to surge forward or back and leave the pickup pipe in the air (even for a couple of seconds) and this air will have to go past the fuel rail / injectors etc at some point causing either lean out condition (burnt valves possible) or engine stumble.

And the HP vane pumps do not take kindly to running in air even for a few seconds - they will get hot and noisy real quick and start spitting out bits of the vanes.

I too looked at running a feed and return to 1 tank only
LP to swirl then HP to feed the rail - return to Swirl and overflow back to left tank.

PL pump to feed fuel from Right tank to left tank to keep left tank topped up and get weight balance better with the fat gitwho drives my car balancing out agaist the light (empty) right tank.

I even figured a way or getting the transfer pump to run automattically by using a second fuel lever sender with a "reserve" light connector. Set the reserve light to come on at anything less than 3/4 tank and it will turn on the transfer pump to keep it at that level

All foor dfor thought

Ian
 
The CAV cars have a set up like this. Not quite the same, but they have a balance pipe between the two tanks and fuel can flow freely between the two. They then pump fuel from one tank and return it to the other.

I have looked into running such a set up in a Tornado, and its just too tight at the back of the car. The other option is to run the fuel line in the passenger cabin, but this poses large IVA problems.

The originals had a huge balance pipe just above the drivers knees, behind the dash. But this was to do with refuelling the cars quickly.

The biggest problems I have come across for the fuel system are the HP fuel pump, and the requirement to keep it supplied with fuel constantly. And the question of fuel return to the supplying tank.

The best I can come up with is: 2 LP pumps, 1 HP pump, 1 swirl pot and 2 solenoids. LP from tank to swirl, HP from swirl to injection, and solenoids to control the return to the supplying tank.

If anyone can come up with something simpler I would be very appreciative. And if you can come up with a way of getting that balance pipe across the car it would make life so much easier.
 

Ian Anderson

Lifetime Supporter
2 tanks
1 change over valve (I am using a Pollack)
1 LP pump
1 HP pump
1 Filter!

It is possible - it's on my car!

OK here goes
Tank to change over valve
change over valve to LP Pump
LP pump to swirl pot
Return from swirl pot to change over valve
Return from change over valve to tank

Then for the HP side

Swirl to HP pump
HP pump to filter
Filter to fuel rail / regulator
Return to Swirl

Simples!

Both pumps run continuously when ignition is on

Ian
 

Andy Green

Supporter
I've used the same system as Ian has described. The only change on my installation is 2 pre-filters in the tanks to stop any debris clogging the Pollack change-over valve. There are only 2 fuel lines which cross the vehicle (within the engine bay) and these are 10mm copper.

Again a lot of thought went into this as I wanted it as simple as possible.

Regards
Andy
 
Ian that's how did mine, worked well.
Only difference is I used a fuel filter on both pick up lines before the Pollack.
 
My plan is to run two LP to swirl, single HP from swirl to injectors. Return from injectors to swirl and overflow from swirl to both tanks.

Then I've designed a pump/gauge controller which will both smooth the gauge response, accurately map capacity to the gauge, show both tanks on one gauge and also 'pick' the highest tank to run the LP from. I just need to design the circuit board and get some made up.
 
I think we have missed the point here. The title says "simple". That implies easy to build. Easy to maintain No bother in operation. Reliable. And accurate fuel level reading. No muss no fuss. Adding a lot of electronics doesn't imply any of this. In fact it should be the opposite, unless you are a stickler for authenticity. Honestly onlookers won't know the difference
Here is what is needed:
One set of pumps(one high and one low pressure).
Constant fuel to the high pressure pump and injectors at all times(no air).
Easy to fill the tanks.
Accurate fuel gauge reading.
Constant even level of fuel in both tanks.

Here is how I propose that it is done.




Let's take a look at it.
This design is an alteration of how Dimi did his build.

First vents. All vent lines are connected front to rear. You need vents in the front and rear of both tanks. They can be joined so that you only need one roll over valve per side. Parking on a hill, up or down allows for equalization of the pressure at both ends of the tank, and the fuel won't be forced up the vent line.
Look at the top and bottom drawing. The end of the tank is sectioned off so that fuel stays around the pickup. The flapper valve allows fuel in but not out. Fuel sloshing around in the tank from braking, acceleration or hills, will not pull fuel away from the pickup. Same for the front of the passengers side. If one end is left "high and dry", the air will go to the swirl tank and exit out the top and back to the tanks. Both return and pickup lines are T'd together
All return lines should be at the reservoir end, thus supplying the pickups with fuel even with sloshing.
The mid tank crossover line will keep the two tanks even on their levels(relatively speaking).
The sender is a Centroid unit with no moving parts. Its length is trimmed to the depth of your tank. It is a slow moving sender of sorts and does not react to quick movements of the fuel level(hollow tube with very small vent at the top). This sender is unique in that when you set it up, it is available to any type of gauge you might have. Just have to order it according to the gauge's requirements. Its settings are adjustable. The high and low level are adjustable for accuracy. There is a setting that you determine for a low level alarm to a warning lite or whatever you want it to be, to alert you that the level is getting low.
Filling the tanks can be done from one side. The crossover will help with that. Yes you may have to wait a minute or two for the leveling to occur then you can continue filling. That waiting time can be used to answer any questions from curious onlookers wanting to know what your car is.

There is a little more discussion and some pics of my setup as it is now,,,, which will be altered this coming winter(need to drive it around a little before I put it up on jacks again).

Bill
 
Hi Keith, in keeping with the keep it simple thinking i only pull fuel of my LH tank for my EFI pump. Both tanks have their own fillers and breathers. I have a low pressure pump running whenever the EFI pump runs that savages fuel from the LH tank into a in tank swirl pot and the EFI pump pulls from the bottom of the swirl pot. The low pressure pump is a designe that will tolerate running without fuel for some time but I have not tried to test this out. The RH tank has a dash mounted swith to a low presure pump that pumps into the LH swirl pot,this is only used as a top up of the LH tank when nessasary. I do have a larger return line from the LH to the RH just in case i leave the dash switch on.
I only have one guage with a rocker switch to each sender unit for cheching tank levels . Hope this helps.

Darrell DRB #46
LS1 G50
 
Bill,
It's a very good idea, and one I would love to implement. The biggest problem we in the UK have is getting fuel from one side of the car to the other, as we cannot run a fuel line through the passenger cabin.
 

Ian Anderson

Lifetime Supporter
Hi Keith, in keeping with the keep it simple thinking i only pull fuel of my LH tank for my EFI pump. Both tanks have their own fillers and breathers. I have a low pressure pump running whenever the EFI pump runs that savages fuel from the LH tank into a in tank swirl pot and the EFI pump pulls from the bottom of the swirl pot. The low pressure pump is a designe that will tolerate running without fuel for some time but I have not tried to test this out. The RH tank has a dash mounted swith to a low presure pump that pumps into the LH swirl pot,this is only used as a top up of the LH tank when nessasary. I do have a larger return line from the LH to the RH just in case i leave the dash switch on.
I only have one guage with a rocker switch to each sender unit for cheching tank levels . Hope this helps.

Darrell DRB #46
LS1 G50
Darrell

What would happen if you inadvertedly left the transfer pump running?
Would it empty the RH tank and overflow the LH tank out the breather?

I managed to do that once when my first Pollack valve broke and it always did the return to the left tank even when drawing from the right! with the price of UK fuel I cannot afford to spill a drop!

Ian
 
Hi Ian if you read the third line from the bottom on my post I have a larger return line from LH to RH and my breather/fuel seperatosr are high up on the rear bulk head.Hope this helps. Explaining things is not my forte.

Darrell DRB#49
LS1 G50
 
Jon,
I don't know how the Tornados bottom is shaped but with a DRB the bottom is corrugated. This leaves a recessed area for the fuel line to be laid and stay protected. It also hides the fasteners for the seats and the crotch strap(s) for the six point harness. A hole has to be punched through the frame and the fuel line routed through it. You don't want any right angles if it can be helped, with the exception of the connection to the tank. That implies that the two holes through the frame are offset so the fuel line won't kink. If you don't have such a bottom then you can punch a hole through the frame work at or about even with the front of the engine bay compartment, and run the line just in front of the engine. The lines have to be fairly level in that the high spots will keep the fuel from flowing. My first iteration was to return fuel to the left hand tank only and let it passively go to the right hand one. I had someone else lay the line and they got lazy and ran it over a frame rail. The first time I turned the fuel pumps on I was greeted with a stream of fuel out of the left hand breather(no roll over valve in line).
Even with the system as I drew it, you have to have a rollover valve in place. Demon Tweeks has several to choose from. Get the one that passively lets air in and out, but stops any fluid flow. The reason is that even with a T setup, you may get more flow to one side than the other(think high speed turns). If that happens, the rollover will stop flow to that tank and force it to the other.
This all has to be thought out. You don't want to be worrying about which pump is running or which valve has been thrown or which tank is supplying the fuel. You may forget. Then you could be stranded. This system works and you don't have to think about it. Besides it is cheaper to build.



I failed to mention in my previous post that the sending unit of the fuel gauge has to be in the main tank area. If it is in the pickup area it will read full all the time until you are "completely" out of fuel.

Bill
 
In my 40 I have an internal pump(lift) in each tank to supply the surge tank at the rear of the main tank on the R/H side.
The surge tank would hold about 10-15 lt,it has a high volume pump internal.
The lift pumps are constantly on and the surge tank spills of at the top back into the R/H tank.
The 2 tanks are linked by a 3/4 hose at the rear lower corners.The line runs across the rear bulkhead in front of the engine.
The vents are in the filler necks that goes through a carby fuel filter and acts as a trap before going onto the charcoal canister.
There are larger 5/8 hoses from the top front of the tank going to the top area of the filler tubes.
I have one sender in the L/H tank as the tanks are linked and self level.
Both tanks are fitted with 2 deviders to section the tank into 3 areas,The deviders have doors that close under brakes to stop fuel running away from the lift pumps.
The lift pumps are an efi pump, I have had the tank pretty low at the track and the pumps have never buzzed.
I dont think there is a simple tank for a 40, they are long and narrow and you need to control the movement of fuel, your surge tank needs to be of reasonable volume so it holds enough to get you through the corner.

I did it this way because I was looking foor a simpler solution but it was still a lot of work at the end of the day.

JIM
 

Dwight

RCR GT 40 Gulf Livery 347 Eight Stack injection
Supporter
old thread but

has anyone installed an in-tank pump in one tank and a low pressure pump for the other tank?
I have a buddy that bought a aluminum tank for his 32 valve EFI motor in his 65 Ford Truck. The tank has a in-tank pump which gave me the idea that I can do the same on my GT 40.
Aeromotive sells kits for this conversion.
Here is part of their ad. Note they use a foam around the pump to control fuel slosh.
++++++++++++++++++++++++++++++++++++++++++
"Are you ready to make the switch to fuel injection, but don't want to run a fuel cell or a loud external pump? Aeromotive has you covered with these Phantom fuel systems. These systems are designed to add a whisper-quiet internal pump to your stock tank that is capable of delivering enough fuel to feed your fuel-injected street rod or musclecar, even in tanks as shallow as 6 inches! Each kit comes complete with an in-tank fuel pump, a black anodized hanger assembly, and an internal baffle system to control fuel slosh and keep the pump submerged. Make the stealthy switch to a Aeromotive Phantom fuel systems and take advantage of modern technology in your classic ride."


Dwight
 
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Ian Anderson

Lifetime Supporter
old thread but

has anyone installed an in-tank pump in one tank and a low pressure pump for the other tank?
I have a buddy that bought a aluminum tank for his 32 valve EFI motor in his 65 Ford Truck. The tank has a in-tank pump which gave me the idea that I can do the same on my GT 40.
Aeromotive sells kits for this conversion.
Here is part of their ad. Note they use a foam around the pump to control fuel slosh.
++++++++++++++++++++++++++++++++++++++++++
"Are you ready to make the switch to fuel injection, but don't want to run a fuel cell or a loud external pump? Aeromotive has you covered with these Phantom fuel systems. These systems are designed to add a whisper-quiet internal pump to your stock tank that is capable of delivering enough fuel to feed your fuel-injected street rod or musclecar, even in tanks as shallow as 6 inches! Each kit comes complete with an in-tank fuel pump, a black anodized hanger assembly, and an internal baffle system to control fuel slosh and keep the pump submerged. Make the stealthy switch to a Aeromotive Phantom fuel systems and take advantage of modern technology in your classic ride."


Dwight
I am not sure it will work in a GT40
From about half tank level braking into a roundabout my Facit LP pump sucks air. I van tell because instead of tick tick it goes bang bang

At quarter tank on a down hill it also sucks air

A sponge around the pump does not sound like enough of a reservoir of fuel

I may be wrong but know how easy it is for my tanks to have air at the rear outlets

Ian
 
Dwight,
Those pumps will work O K. You have to have the internal baffle system mentioned in the ad to keep fuel around the pump. If not you will fry the pump. The proplem you will have is that the tanks don't have a flat bottom. It is angled up to the side and that requires a flapper setup, or a series of fixed baffles that will slow down the flow of gas away from the pump.Here is mine.


Bill
 
One of my friend, rebuilding a mono replica with EFI engine, is going to use a in-tank HP pump to feed directly the EFI. It's an aeromotive phantom, with feed and return line on the same hanger + built-in foam and rubber baffle.
He had received the pump, and said me it looks really very nice.

The tanks will be filled with explosafe foam, to reduce fuel sloshing, and the 2 tanks will be connected with 8AN fuel line (running in the engine bay).

The car is still in building process (the engine is still on its crate !), I'll let you know if it works, and if it's so simple as it seems...
 
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Dwight all my pumps are intank.
Walbro do a small 500hp pump , its quite.
I run small efi pumps for lift pumps, never had a problem, I do have a tank with trap doors.

Jim
 
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