Fuel Tank Swap

[ken87cutlass]

...Thanks, for the pics and information. Now I can refinish the tank.

No problem. You doing tb injection or multiport?

Multi port, going with the Accel system. One of the guys on ROP is a dealer, he's setting me up a base map to get me going and I have a shop, Willy's Carbs, relatively close that I'll go to to get it fine tuned. I know, I said Will'ys Carbs but they have a chassis dyno and a really good FI guy also.

Out of curiosity, whats the reason anybody would switch from a standard cutlass tank to a GN tank? is there that much of a difference in volume for the trouble?

As was mentioned, the GN tank has a "bucket" if you will installed underneath the fuel pump hanger. The smaller bucket receives the fuel from the return line staying "full" and keeps the pump from sucking air. Not critical on a carb car because the carb has float bowls full of fuel. On fuel injected cars, if you suck air into the fuel line you will have problems with fuel starvation.

 

[ken87cutlass]

SO, to answer your question, if you want to run Fuel Injection, get one of these tanks, and the correct sender/pump hanger. (GN/FI monte)

Ok, got the tank figured out and came to the fuel pump hanger. I did not realize that the GN fuel return line was the 1/4 inch one!!!

I am running a 3/8's supply line to the front and was planning on running one to the back for a return. That begs the question of how to connect the 3/8 return line to the 1/4 inch return on the hanger? Is the 1/4 line sufficient or will this be a restriction that will cause problems?

 

[crucial118]

The 1/4 return was a restriction for my setup. It sent fuel pressure to around 100psi. I ended up running a separate 5/16 line back to the tank and drilled a hole at the top and installed a brass 5/16 barb fitting(from Home Depot) with a nut directly to the tank. I also used a little JB Weld around the fitting, on the outside, to make everything leak proof. This brought my fuel pressure back down. You could try a reducer fitting at the 1/4 line, but too many clamps = too many chances to leak.

 

[ken87cutlass]

The 1/4 return was a restriction for my setup. It sent fuel pressure to around 100psi. I ended up running a separate 5/16 line back to the tank and drilled a hole at the top and installed a brass 5/16 barb fitting(from Home Depot) with a nut directly to the tank. I also used a little JB Weld around the fitting, on the outside, to make everything leak proof. This brought my fuel pressure back down. You could try a reducer fitting at the 1/4 line, but too many clamps = too many chances to leak.

Got a picture of the fitting?

Did you run a solid line to the bottom of the tank like the original 1/4 line did? IIRC, the factory did this to keep the fuel from becoming aerated.

 

[crucial118]

I ran a -5 AN line from my fuel rail to the tank. That's how most plumb in race lines. No, I didn't run a line to the bottom of the tank like the original return line. I was a little worried about that when I installed just the barb fitting, but It seems to be working without it. The only thing I can think It might affect is the gauge float. Sometimes it goes up or down when I floor it, but it usually is pretty static. I guess you could always hook a 5/16 hose to the inside attachment and run that to the bottom of the tank. Hindsight is 20/20. I don't have any pics of the barb attachment, but if you go to Home Depot in the plumbing isle, you will see what I'm talking about.