Fuel tank and pump setup with return style regulator.

[NickV]

Hello,

Have a gallonswirl tank out of my 40.
Has a newer wet pump with regulator.
Both my low pressure pumps fed in to float control valves thru the top.

Ran a Holley with it turned down.
Believe it's about 6 inches wide and maybe a foot tall.
Has side plates on the bottom to attach.
Was mounted behind ps fuel tank in hall.
Will locate it if it would work for ya.

Pay the shipping...

Hey Bob, you mentioned you previously used the same setup and had float control valves to turn on the transfer pumps as needed to keep the surge tank happy. Do you have details on the switched used? And why did you change up your system just out of curiosity?

 

[Ian Anderson]

I had thought the same thing way back but never did it as I used a Pollack change over valve and it worked. I was going to get a fuel gauge sensor with an adjustable “reserve” / fill up now light trigger and use that , through a relay to power the transfer/ crossover pump.

I never did it as once the second tank is empty I could figure an automatic way to stop the transfer pump for running flat out only pumping air and thus burning out.

Manual transfer switch is ok till you leave it on and overfill the other tank and spew fuel everywhere.

Ian

 

[NickV]

I had thought the same thing way back but never did it as I used a Pollack change over valve and it worked. I was going to get a fuel gauge sensor with an adjustable “reserve” / fill up now light trigger and use that , through a relay to power the transfer/ crossover pump.

I never did it as once the second tank is empty I could figure an automatic way to stop the transfer pump for running flat out only pumping air and thus burning out.

Manual transfer switch is ok till you leave it on and overfill the other tank and spew fuel everywhere.

Ian

Thanks for sharing! I've been reading about these valves. Seems like this could be another good option. Thanks for the tip!

Also good point about burning out the transfer pump if the tank runs dry.... and about overfilling due to a manual switch. I should be more honest with myself that I could easily forget to turn it off LOL.

Would you share more about your change over valve set-up?
Did you go with a 6 port return style or just a 3-port?
My only concern with the change over valve concept is that the pumps would need to turn on / off when a tank is selected / un-selected. But these Pollack valve seems to actually do that after looking at wiring diagrams... This way both pumps wouldn't need to always be running and grinding on the same fuel when not in use heating it up.
It looks like the switches can also be incorporated to change over fuel level sending units?

Thanks again for the input.

 

[Ian Anderson]

Thanks for sharing! I've been reading about these valves. Seems like this could be another good option. Thanks for the tip!

Also good point about burning out the transfer pump if the tank runs dry.... and about overfilling due to a manual switch. I should be more honest with myself that I could easily forget to turn it off LOL.

Would you share more about your change over valve set-up?
Did you go with a 6 port return style or just a 3-port?
My only concern with the change over valve concept is that the pumps would need to turn on / off when a tank is selected / un-selected. But these Pollack valve seems to actually do that after looking at wiring diagrams... This way both pumps wouldn't need to always be running and grinding on the same fuel when not in use heating it up.
It looks like the switches can also be incorporated to change over fuel level sending units?

Thanks again for the input.

I used a 6 way valve And only 2 pumps. (I sucked the fuel through the Pollack)

So
Fuel tank to filter to Pollack to Low Pressure pump to Swirl Pot With a return via the Pollack to the same fuel tank.

Then from the Swirl to a High Pressure Pump, to fine filter, to fuel rail, then pressure regulator and return to swirl.

You could also do the same with a change over switch, two Low pressure pumps couple of non return valves and a to and from the swirl.

Tank to filter to pump through non return valve to T connecting two tanks to swirl exit swirl to T and from their th rough Solenoid and back to tank..
So when you click upgrade change over switch it powers to the pump and solenoid on that side, switch the other way and draw from other tank.

More bits to fail and also the solenoid has to be powered to be open so an additional current draw and call me overly cautious but electric and solenoid generates heat and hence potential source of fire.

The Pollack only has power to it for perhaps 3 seconds as the valve changes ….after that no more current draw till you switch the other way..

One last thing you may consider is on the return from the swirl run it through a fuel cooler /radiator.. the pumps running generate heat and it also absorbs heat from fuel rail, the swirl takes on heat from ambient under the rear clip. The fuel can actually get reasonably warm, especially idling in heavy traffic.

Ian

 

[NickV]

Hey Ian,

Fantastic information. Cant thank you enough. I hadn't considered running a single pump to suck through the selector valve and eliminate the third pump... definitely something to consider.
Also I share your consideration of heat in fuel... it may be an issue...

I think a solenoid switch is also out due to the constant power draw.

Do you happen to remember what fuel pumps you ran? I am hoping to not cause a bottle neck with this valve but not able to confirm flow rate. Stock my engine had a fuel pump rated for 255 lph, but I may throw a little more fuel at it given it has some upgrades to flow more air... My pump has a -8AN inlet and the final fuel filter has a 3/8 NPT inlet/outlet. So since the selector valve supply needs a 3/8" ID hose I think the hose will flow enough fuel... but I am wondering if the internals of the valve can flow enough as well. May be something that I need to role the dice on. Just thought I'd ask to verify what your pumps were so maybe I could confirm a flow rate proven to work. Unfortunately I can't seem to find any schematics or details on these valves...

I think I have narrowed down to the following two options pictured below. Let me know if I missed something crucial or if I am misunderstanding your method.

My final concern is that having the secondary fuel pump so far from the tanks ( as drawn on the right) will require a lot more scavenging while trying to get fuel moving... maybe check valves would help hold fuel in the lines?

Thanks,
Nick

 

[Ian Anderson]

Info on my fuel pumps.
Low pressure was Facit Red Top.
Main fuel pump Bosch 044
Engine was mild at only 260 HP

If you are worried about the valve being restrictive then your diagram one is the way to go.

Ian

 

[Sean Starkey]

Hey Sean! Wanting to join in on this fuel discussion....
I am working out my fuel system for my RCR right now as well and stumbled on this recent post as well as your posting in the Fuel technical forum... (the car shows up this fall hopefully)

I was considering the exact same solution you were previously with the equalizing line. However I read you opted for two low pressure pumps feeding each tank into a swirl pot. I am doing EFI so I will definitely need a swirl pot/surge tank like you chose.

I too was having doubts about the equalizing line concept.
I think it is a good point that if the line was damaged or started a leak there would be no stopping it (vs a pump pulling fuel up out of a tank)
Also I plan on doing lots of performance driving, so I think I would also worry about additional fuel starvation as now g forces can push fuel side to side away from the primary tank on long turns. Of course a small check valve may remedy this... and maybe it would not even be an issue as there will be a swirl pot and a small equalizer line can't flow much fuel...

Regardless I think I have also abandoned the concept.

I am now considering a low pressure "transfer pump" feeding the other "primary" tank. The transfer pump could just be on a manual switch. I would push fuel over as needed. The primary tank would transfer fuel to a swirl pot which would feed a high pressure pump and regulator for EFI. Currently I have the regulator sketched out to feed back to the surge tank. I would then have a return line also back to the primary tank to prevent an overflow. Sounds like a lot of lines though...

Your solution also interests me as it is a slightly different take. However I have a few questions about it.
I am not sure I am understanding how your fuel pumps will be switched on/off as needed. Either they will be always on with a return line to prevent overflow... or you have switches with floats. Would you please explain?

Side question... were the aeromotive low pressure pumps specifically rated to scavenge air momentarily upon turning air as they suck fuel up line? I am not finding much about it. Not too worried about it, just surprised to not hear more about this. Typically fuel injection pumps are fully submerged these days to mitigate dry starts. Would you please share the part #'s you chose? My fuel injection system stock had a fuel pump rated for 255 lph so trying to exceed this # and let my regulator do its thing.

Hi Nick,

I abandoned the cross over line. Although I found on Jason's thread that he made it work successfully by using a SS bar to protect it. And it looks good. Link : https://www.gt40s.com/threads/jasons-coyote-powered-rcr40-downunder.26333/page-12

As far as my fuel pumps. I plan to have a On-OFF-ON toggle switch to run 1 pump at a time. I will have high flow check valves to keep from pushing fuel to the opposite tank. Some surge tanks have floats in them to cycle the pump on and off.

The Aeromotive fuel pumps are 11209 pumps. they have a flow rate of 90 gph/340 lph each. Aeromotive says to mount them close and below the tank. They also say don't run it dry. I have used them before mounted about 1 foot above the fuel tank and had no issues with them. Since I will already have check valves in the system to prevent flow going back to the tank, I believe it should work well for my application. For the surge tank I got a AEM 50-1005 pump with a flow rate of 106 gph/400 lph.

Regards,

Sean

 

[NickV]

Hi Nick,

I abandoned the cross over line. Although I found on Jason's thread that he made it work successfully by using a SS bar to protect it. And it looks good. Link : https://www.gt40s.com/threads/jasons-coyote-powered-rcr40-downunder.26333/page-12

As far as my fuel pumps. I plan to have a On-OFF-ON toggle switch to run 1 pump at a time. I will have high flow check valves to keep from pushing fuel to the opposite tank. Some surge tanks have floats in them to cycle the pump on and off.

The Aeromotive fuel pumps are 11209 pumps. they have a flow rate of 90 gph/340 lph each. Aeromotive says to mount them close and below the tank. They also say don't run it dry. I have used them before mounted about 1 foot above the fuel tank and had no issues with them. Since I will already have check valves in the system to prevent flow going back to the tank, I believe it should work well for my application. For the surge tank I got a AEM 50-1005 pump with a flow rate of 106 gph/400 lph.

Regards,

Sean

Hey Sean,

Thanks for sharing the info. I like your check valve concept.
Also happy to hear that these pumps can hold up to momentary dry starts when not gravity fed... certainly a concern of mine.

One question... How do you plan to handle your fuel return? You'd need to make sure the overflow from the surge tank is passed to whichever fuel tank is in use right?

Thanks,
Nick

 

[Brian]

Rather than add the complexity of diverter valves and check valves, my plan was to have the surge tank only return to one tank, so the secondary tank's (without the surge tank return) pump would half act like a jockey pump.

My thought was a home brewed micro controller module that would read the 2 fuel lever senders, and proportionately run the 2 tank pumps trying to equalize the tanks and also send out a single fuel level signal to the gauge that would indicate the average in the cockpit.

So in reality, the main tank would run near flat out and the secondary only intermittently to try to track the fuel level of the main tank.

With the surge tank being near the hot engine and the heating of the fuel by being pumped then passing around the fuel rail then through the regulator and back to the surge tank you need the surge tank returning to a main tank and being refilled with cool fuel or even with EFI, you could run into vapor lock like pump cavitation issues. For that reason, I don't like the float or switches to keep the surge tank full.

 

[Neil]

Rather than add the complexity of diverter valves and check valves, my plan was to have the surge tank only return to one tank, so the secondary tank's (without the surge tank return) pump would half act like a jockey pump.

My thought was a home brewed micro controller module that would read the 2 fuel lever senders, and proportionately run the 2 tank pumps trying to equalize the tanks and also send out a single fuel level signal to the gauge that would indicate the average in the cockpit.

So in reality, the main tank would run near flat out and the secondary only intermittently to try to track the fuel level of the main tank.

With the surge tank being near the hot engine and the heating of the fuel by being pumped then passing around the fuel rail then through the regulator and back to the surge tank you need the surge tank returning to a main tank and being refilled with cool fuel or even with EFI, you could run into vapor lock like pump cavitation issues. For that reason, I don't like the float or switches to keep the surge tank full.

A few digital logic gates can give you what you want, a microcontroller is a bit of overkill.

 

[Brian]

I'm sure it is, but thought it might get a few other little features like PWM the tank pumps for soft starts since they'll be cycling.

 

[Sean Starkey]

Hey Sean,

Thanks for sharing the info. I like your check valve concept.
Also happy to hear that these pumps can hold up to momentary dry starts when not gravity fed... certainly a concern of mine.

One question... How do you plan to handle your fuel return? You'd need to make sure the overflow from the surge tank is passed to whichever fuel tank is in use right?

Thanks,
Nick

Nick,

I finally nailed down how I plan to build this fuel system. I needed to gather all the parts to see how it was going to work, and figure out what was needed. Attached is a sketch of my plan.

You are correct, the biggest hang up I had was returning the fuel from the surge tank to a fuel tank.

I am going to use the passenger tank to feed the surge tank and return to that same tank. I will weld another bung in the passenger tank for the return line. I will then use a pump to transfer fuel from the driver tank to the passenger tank. The surge tank will run a 044 pump to the return regulator back to the surge tank.

I will post some pictures once I get it all completed, hopefully this weekend.

Regards,

Sean

 

[Trevor]

I used a 6 way valve And only 2 pumps. (I sucked the fuel through the Pollack)

So
Fuel tank to filter to Pollack to Low Pressure pump to Swirl Pot With a return via the Pollack to the same fuel tank.

Then from the Swirl to a High Pressure Pump, to fine filter, to fuel rail, then pressure regulator and return to swirl.

You could also do the same with a change over switch, two Low pressure pumps couple of non return valves and a to and from the swirl.

Tank to filter to pump through non return valve to T connecting two tanks to swirl exit swirl to T and from their th rough Solenoid and back to tank..
So when you click upgrade change over switch it powers to the pump and solenoid on that side, switch the other way and draw from other tank.

More bits to fail and also the solenoid has to be powered to be open so an additional current draw and call me overly cautious but electric and solenoid generates heat and hence potential source of fire.

The Pollack only has power to it for perhaps 3 seconds as the valve changes ….after that no more current draw till you switch the other way..

One last thing you may consider is on the return from the swirl run it through a fuel cooler /radiator.. the pumps running generate heat and it also absorbs heat from fuel rail, the swirl takes on heat from ambient under the rear clip. The fuel can actually get reasonably warm, especially idling in heavy traffic.

Ian

Hey Ian, do you have a diagram for this showing where the Pollack is? I like the idea of only 2 pumps. Would the pump be something like a FAC-40290 to be able to suck that well?

 

[Ian Anderson]

Trevor

i ran a Facet Red top as my low pressure pump and a Bosch unit as my high pressure.

My engine was 3.9 litres Rover based and 256hp so mild compared to a lot on here so you will need to chose your pump according to what your engine will drink at full throttle.

Quick sketch attached.

worked for 15

years though I did have the original pollack valve fail after about 8 years, it kept returning to the same tank but the replacement price was low and easy enough to change out.

Ian

 

[Ian Anderson]

And for some reason the photo is upside down

 

[Neil]

What is a "Pollaock Valve"?

 

[Ian Anderson]

What is a "Pollaock Valve"?

Pollak, 6-Port Fuel Selector Valve with Switch - Welcome to Oilybits U.K.

Pollak, 6-Port Fuel Selector Valve with Switch, alternative to Pevekoil Valve, 3 6 Port Changeover Valve, Biotuning, Tank Selector Valve, Switchover valve Oilybits U.K. Order Online with Confidence.

www.oilybits.com

 

[Liam39]

Why not run a high pressure, in-tank, starvation protected pump in each tank, through a pollack 6-port valve and eliminate the surge tank/3rd pump?
There are various options for in-tank pumps which avoid fuel slosh starvation issues from Summit - inc Aeromotive, Holley and Summit's own branded one.
It seems simpler than running a surge tank and quieter than an external 044 pump.

Pardon Our Interruption

 

[Ian Anderson]

Why not run a high pressure, in-tank, starvation protected pump in each tank, through a pollack 6-port valve and eliminate the surge tank/3rd pump?
There are various options for in-tank pumps which avoid fuel slosh starvation issues from Summit - inc Aeromotive, Holley and Summit's own branded one.
It seems simpler than running a surge tank and quieter than an external 044 pump.

Pardon Our Interruption

Most fuel tanks would work that way but in a GT40 the tanks are long and narrow, not square footprint but HP pumps do not take to running dry…..a few seconds and the close tolerance rotors die ……….noisy pump at first but slowly will not be able to generate the required pressure.

In my car from half tank down I could hear the Facit red top sucking air when slowing and the fuel sloshed forward. The red top could handle drawing air and return to normal pump mode Once stopped or back on the loud pedal.

only thing I have seen that may change my mind is Hydramat, but that was not available in2005/2006 when I was building my car.

Ian

 

[Neil]

Pollak, 6-Port Fuel Selector Valve with Switch - Welcome to Oilybits U.K.

Pollak, 6-Port Fuel Selector Valve with Switch, alternative to Pevekoil Valve, 3 6 Port Changeover Valve, Biotuning, Tank Selector Valve, Switchover valve Oilybits U.K. Order Online with Confidence.

www.oilybits.com

Ah so! Thank you.