8 stack system

[617cobra]

I have put an 8 stack system on a 351 cleveland. It is dyno tuned and put out 602hp/524tq. My question is this, while on the dyno we just looped a piece of rubber fuel line from one fuel rail on the front to the other. this of course looks... well lets just say not good. I was wondering if anyone had a better mouse trap. It was suggested to cap off the front of the fuel rails and put a T in the supply lines to feed back to the fuelpressure regulator and on back to the tank. That would involve 2-Y splitters, 2-T's and extra fuel lines. this would be a bit busy for my taste. I saw something on a momar injection system picture, that looks like a fuel block that connects the two fuel rails and also had a port for a fuel pressure regulator. the fuel rails are 1.25 inches center to center and too close for bending -6 tubing.

Suggestions??

[wkooiman]

Fuel injection or Webers?

If you are talking Webers, you can buy AN banjo fittings, and the routing isn't very difficult. I currently run a Carter electric with no regulator to a tee, and 2 lines, one for each side.

If you are talking FI, it depends on what you have. I have seen several. They all had fuel rails, but I don't recall how the return line was plumbed.

[Dwight]

[bobcowan]

I have seen that fuel block. But I think it's a custom piece, as I'v never been able to find one.

You need some kind of cross over or return at the other end of the fuel line. Otherwise the fuel will dead head, and that's not a good thing. Ideally, you want fuel flowing through the rails.

If you use a FPR that has two inlets, you can bring a return line back from the end of each rail. Something like Aeromotive.

You can see how I did this with some braided line. But the radius was too tight, and the hose eventually failed.



Then I looped it like this. The radius was big enough to maintain integrity. But every time I wanted to do something with the distributor, that hose got in the way.



So, eventually, I went with a pair of 180* fittings, and individual return lines back to the FPR.





My other thought was to use some 3/8" hard line, and loop it around kind of like a highway cloverleaf.

[albanycobra]

Here's mine. I ran he lines down the outside.

[617cobra]

Thanks for the replies. Nice job guys.

My 8 stack is FE. It was tuned by David with FAST systems here in Memphis. He told me I could come from the tank/pump up to a Y block, from the Y block to the back of each fuel rail where I can attach the supply lines to a T on each side that is connected to the fuel rails, and from the drop on the T, run back from each one to another Y block to bring it back to 1 line, then thru the fuel regulator and the return line back to the tank.

Has anyone run this setup? As I understand it, a return style system is more for the fuel pump, keeping it cool and flowing, than anything else and the above set up would seem to do that. I don't know how this type setup would be as far as dead heading..??

Bill

[Gaz64]

A lot of EFI cars these days run pumps with the regulator in the tank, fixed fuel pressure, dead headed.

As far as yours is concerned, I would do this:

Main line fit a tee of your line size say 8AN, the straight run is the main flow to the engine. The tee goes to the regulator, the regulator sets the fuel pressure and dumps the excess to the return line.

Aeroflow Male Flare TEE 8AN Black ALL Sides Male AN AF824 08BLK | eBay

After the tee on the straight run to the engine split the line with a y block:

8 AN Flare TO 6 AN Flare Union Billet Y Block Compatible Speedflow Proflow | eBay

Up to the rails -6 line. Cap the front ends of the rails semi-permanently.

AEM 2 604 High Volume Fuel Rail Port Plug 6 9 16" 18 | eBay

1 2" NPT Aluminium Port Plug Block OFF Blanking Allen HEX Socket Fitting Black | eBay

All examples of course.

Gary

[Dwight]

On my Eight Stack System I ran a fuel line from the in tank fuel pump to the regulator, fuel filter to number one injector, then two, three and four, from four to number five, six, seven, eight. From # eight, a return line to the tank. No tee.
My intank pump is in the driver side tank and the regulator is just above the tank on the bulkhead. It was easy to run a line from the regulator / fuel filter to number one injector without 90, 45 degree fittings.


Regulator before the injectors. The shortest lines with no 90 degree fittings is best.

IMHO
Dwight
I'll try to post a picture later.

[Gaz64]

Originally Posted by Dwight

On my Eight Stack System I ran a fuel line from the in tank fuel pump to the regulator, fuel filter to number one injector, then two, three and four, from four to number five, six, seven, eight. From # eight, a return line to the tank. No tee.
My intank pump is in the driver side tank and the regulator is just above the tank on the bulkhead. It was easy to run a line from the regulator / fuel filter to number one injector without 90, 45 degree fittings.


Regulator before the injectors. The shortest lines with no 90 degree fittings is best.

IMHO
Dwight
I'll try to post a picture later.

Dwight,

Your description doesn't make any sense, you have a return line after injector 8 with a free path back to the tank?

And your regulator is between the pump and the injectors?

By the sound of that, hows does it get fuel pressure?

[Dwight]

You are correct I made a mistake.

I'll go to the shop and look at it. I have not started the motor so it's a untested system.

On my Cobra I used the regulator to feed both rails and the return line is off the regulator also.

Dwight

[glenview289]

Dwight, I agree with Gaz64. When installing my Accel system (per their recommendations), I went from fuel pump, to the filter, to a hard tube down drivers side frame, to a braided stainless hose up to front of drivers side fuel rail, cross over to passenger side fuel rail at back of engine, down from front of passenger side fuel rail with a braided stainless hose to the regulator mounted on passenger side frame. This will guarantee the injectors and everything between the fuel pump and regulator will be at the desired set pressure. A return line from the regulator to the fuel tank completes the system. It was Accels thought that a loop system would keep the fuel pressure more consistent to the injectors than a dead headed system where the injectors pick up one after another down the fuel rail. Just more food for thought.
Bill

[Dumpling]

gessfordf has it or can make it for you.

[Dwight]

I checked this morning. I have a check valve on the return line before the tank. At the moment I forget the pressure setting on the check valve.

I'm using a Aeromotive regulator on the GT40 motor which has an in and two out ports. Also a 1/8" port for the pressure gauge. This is why I need a return line from the fuel rail.

The Mallery on my Cobra has an inlet port, two supply (out) ports and a return port to return the excess fuel to the tank.

It's my understanding that you want to regulate the fuel pressure down to what is acceptable pressure for the system. In my case 40 lbs. My fuel pump pressure is a lot more than 40 PSI.

If I have a hundred PSI on the injectors I will have to much fuel. A rich condition.

Dwight

Learning every day

[Gaz64]

Dwight,

I understand the front of your system, but the check valve you have in the return line?

There should be NO restriction between the regulator return port and the fuel tank.

To me, the check valve you are referring to would be in the main line after the pump as a non-return valve.

[Dwight]

I have the check valve in the line from the other tank. My mistake when I looked at the pictures in a folder.

I see my mistake now. Thanks

When I bought the GT 40 the fuel system was plumbed. I replaced the motor and fuel lines but hooked it up as I found it.

When I added the intank fuel pump I hooked it to the return port on the regulator.

Thank again for pointing out my mistake.

I have some work to do.

Dwight