What do i need for my EFI Fuel line setup?

[swinger74]

Hello, i have a a 74 dart with a mild 383. I have a new fuel tank with competition engineering fuel sump and 3/8" fittings. (http://www.summitracing.com/parts/cee-4040) I was heard good things about the walbro gsl-392 fuel pump, but thats where my knowledge ends.

What fuel line do i need (size and material? rubber/braided/other?)
Do i just block off the other 3/8 fitting on the sump?
Can i run the return line to the sending unit?
What fuel filter and regulator do i need?
Am i missing anything?

Thanks
Ryan

 

[BillGrissom]

I think you could use either the 2nd 3/8" fitting or the sender's 5/16" fitting for return. The later seems easier since you have that in the factory line. I used 3/8" tube for supply to my Walbro EFI pump in my 65 Dart, but 5/16" is fine since Magnum engines used that. You need a simple high-flow carb-type filter before the fuel pump. You can find a $4 metal one w/ 3/8" tubes at auto parts. After the EFI pump, you need a good high-pressure EFI type. I used the $20 Wix filter/regulator for Corvettes (56 psi, fixed), as many rodders do. It has 3/8" inlet and outlet and I recall 5/16" return, all quick-connect fittings (male & female). However, your TBI or fuel rail may have a built-in regulator. I put my EFI pump on the frame rail in the engine bay. People say that won't work, but mine works fine in 2 cars.

 

[swinger74]

Bill thanks for the reply. Right now my fuel rails have no regulator. So you just used rubber efi line for the whole setup? The return line comes off the regulator? Do i need to run a return line from the engine?

 

[moparlover]

http://www.holley.com/types/Billet%20Fuel%20Pressure%20Regulators.asp

they have different psi ranges (not sure what you need, carbs are 7psi but EFI varies)

but for each of those regulators on that page, they have an instruction sheet with diagrams on the lower right part of the page. good stuff there. it requires adobe pdf reader to open the instructions.

 

[71Scamper]

Bill thanks for the reply. Right now my fuel rails have no regulator. So you just used rubber efi line for the whole setup? The return line comes off the regulator? Do i need to run a return line from the engine?

I would run as much steel line as possible. NHRA/IHRA limits you to only 3 feet of rubber line. Plus in way of safety your better off with mostly steel line. I would also use 3/8 even though the magnum can run on the 5/16. This leaves room for improvement. If you decide later to build your engine up some more and it starts to have the appetite for more fuel, you won't be limited by the smaller line.

Yes, you will need to run a smaller return line from the regulator. What the regulator does is only let in the predetermined amount of fuel psi/volume to the fuel injectors and dumps the excess back to the fuel tank.

 

[85glht]

My only comment is to NOT use the second fitting in the sump for your return. With the two fittings being so close to each other, you have the possibility of airating the fuel.

 

[swinger74]

thats what i was thinking if i used the second hole, so i should just cap it? What is everyone using for their fuel line? i dont have any fuel benders/tools either so i will probably have to pick up a couple as well.

Ryan

 

[inkjunkie]

EFI vehicle I built a while ago I just used the filler neck for a return point. Took the appropriate size aluminum tubing and had a fitting tig welded into it, cut the oem hose and slid this into it with clamps. Used the oem pick up/sender with a Walbro style inline pump. Motor had factory efi so I just used all of it for the regulator and rails. Used hose and fittings from a local hose supplier. Fittings were brass (?) an fittings, cost about 20% of the anodized stuff. Fuel return idea.....http://www.moroso.com/catalog/categorydisplay.asp?CatCode=32029

 

[85glht]

thats what i was thinking if i used the second hole, so i should just cap it?

Yup, just cap it.

 

[BillGrissom]

Bill thanks for the reply. So you just used rubber efi line for the whole setup?

No. I used minimal rubber. I bought coils of steel tubing on ebay, 3/8" & 5/16". I used the later for tranny cooling lines too. "Just used rubber" would be a mis-nomer since that would be very expensive ($5/ft for EFI hose) and a lot of work to support it, plus the danger.

The return line comes off the regulator?

Yes. The Corvette filter/regulator has 3 ports: inlet, outlet, return. All are quick-connect type I recall. You can find many photos and posts on rodder sites, or search for my post w/ photos.

Do i need to run a return line from the engine?

Only if you use a regulator in your TBI or fuel rail. With a separate regulator, only 1 tube goes to the engine. You can put the regulator anywhere after the high-pressure fuel pump. It is just a spring-relief bypass. One advantage of having it on the fuel rail is that most control pressure relative to manifold pressure, which the filter/reg does not. However, if your computer senses MAP, that can simply be part your "fuel map" or equations.

 

[swinger74]

So i think i am making this alot harder than it needs to be. the way i have it in my head is using braided stainless from the sump to a filter to a fuel pump then the regulator, then hard line up to the last foot then braided to the fuel rail. Is that right? or am i over complicating things?

This is what i am looking at.

fitting from the sump http://www.summitracing.com/parts/ear-840106erl/recommendedparts

Braided line http://www.summitracing.com/parts/sum-220984/recommendedparts

to this http://www.summitracing.com/parts/sum-220690

to this filter http://www.summitracing.com/parts/fra-960001/overview/

to this pump http://www.summitracing.com/parts/vpn-gsl392/recommendedparts
with these fittings http://www.summitracing.com/parts/rus-670470

to this fitting http://www.summitracing.com/parts/sum-220690
to this regulator http://www.speedwaymotors.com/LS1-Fuel-Filter-Fuel-Regulator-Kit,41791.html

than hard line to the fuel rail? is there a better way?

Ryan

 

[jbc426]

So i think i am making this alot harder than it needs to be. the way i have it in my head is using braided stainless from the sump to a filter to a fuel pump then the regulator, then hard line up to the last foot then braided to the fuel rail. Is that right? or am i over complicating things?

This is what i am looking at.

fitting from the sump http://www.summitracing.com/parts/ear-840106erl/recommendedparts

Braided line http://www.summitracing.com/parts/sum-220984/recommendedparts

to this http://www.summitracing.com/parts/sum-220690

to this filter http://www.summitracing.com/parts/fra-960001/overview/

to this pump http://www.summitracing.com/parts/vpn-gsl392/recommendedparts
with these fittings http://www.summitracing.com/parts/rus-670470

to this fitting http://www.summitracing.com/parts/sum-220690
to this regulator http://www.speedwaymotors.com/LS1-Fuel-Filter-Fuel-Regulator-Kit,41791.html

than hard line to the fuel rail? is there a better way?

Ryan

I used a surge tank set-up. A low presure pump fed through a fuel filter-water separator from 3/8ths pick-up in a new tank through 3/8ths line to another fuel filter-water separator to the surge tank mounted up front, and back through 3/8th line to a 3/8ths return line in the fuel sending unit( I silver soldered in the 3/8th return where the 5/16ths fitting was). This all flows at high volume, but at very low pressure - about 0psi with a constant circulation of fuel from the tank to the surge tank.

The front mounted surge tank has a Duetschworks 200 internally mounted EFI pump that circulates the high pressure fuel through the billet fuel rails and back into the surge tank through a pressure regulator. I have mine set at 45 psi.

This system is extremely resistant to the introduction of virtually ANY air into the high pressure side even with a low fuel level at high G's.

I'm using a stock tank. It's all that's necessary, but a baffeled & sumped tank would be even better for high horsepower drag or road race cars with slicks.