When running a return loop fuel system with a stock tank...

[doublekrossd]

I'm upgrading my fuel system this year to an electrical pump (A1000), big -10 lines, and a return style regulator. I have a 1/2" pickup and a new stainless tank. How have you guys plumbed in your return line? I thought about putting a sump in the tank and returning through the sending units pickup tube but something about cutting up a perfectly new tank doesn't appeal to me. Then I thought about just welding in the appropriate sized bung into the upper part of the tank to install a regular AN fitting. Any advice or ideas? Thanks in advance guys!

 

[toolmanmike]

I have heard of returning it downstream from the gas cap in the filler neck. Can you get a sender unit with a return line already installed? (Like from a early to mid 70's car)

 

[doublekrossd]

Not that I've found yet...

 

[vintage chromoly]

Well the bung in and be done with it.

My sender has a return on it, but it's 5/16" and wont flow enough for what you're doing.

 

[doublekrossd]

Well the bung in and be done with it.

My sender has a return on it, but it's 5/16" and wont flow enough for what you're doing.

Where did you get your sender? Maybe they have a larger size?

 

[dieseldazzle]

I've done all 3 depending on the application.

I really like the tanks inc setup i just put in a 70 chevelle. It returns through the fuel pump hat

 

[doublekrossd]

I assume by "fuel pump hat" you mean where the sending unit is goes? pardon me for my misunderstanding if this isn't what you meant. I was just over crawling around under the car and it kinda looks like welding a bung along the side of the sending unit (or in proximity) is going to be the way to go due to the lack of room to get around in the car. I also like the idea of splitting the fill hose/ neck and routing the return that way but then I'd have to route the fuel line around the axle leaf spring area and for some reason that's not seeming like a great idea...

 

[Outlaw525]

It's kind of hard to see in this picture, what I did was:

Installed an aftermarket sending unit with 1/2" pickup.
Drilled a hole in the tank above the level of the pickup tube outlet and installed a AN fuel tank bung for the return line. Has been working good- no issues or leaks.

I will try to get a better pic tonight.

 

[Dreamcatcher]

Is that pump noisy? I installed on in the Chevelle and it was very loud inside the car as well as outside. Even with magna flow mufflers you could hear it while running down the road.

 

[Yatzee]

Weld the bung if possible, use a bulkhead fitting if not but be very careful where and how you return the fuel. You cannot just dump the fuel back in the tank without consequences - turbulence and high fuming. A fuel guide pipe should be on the inside of the tank to direct return fuel.The outlet should be at least 1/2 off the bottom as not to stir up sediment on the bottom of the tank, and away from the float of the sending unit. Shooting the inlet of the return at an angle against the side wall of the tank at the front gentles the return jet and produces the least amount of fuming in the tank. Make a diffuser for the end of the return. I use a bulkhead fitting with soft copper line soldered into it on the tank side so I can reach in through the sender hole and bend it or at least view it's position. Altered stainless fender washers backed on both sides with rubber buna washers seals just fine if no one offers to weld on a fume infested tank. If you install it near the sending unit ( off to one side ) you can reach through the hole to hold one side of the bulkhead fitting with a wrench while you tighten the outside nut. Have had one installed for five years now without issue and it makes draining the tank a snap if you ever need to.

 

[dieseldazzle]

Agreed you can't just dump fuel back into the tank. I would use a bulkhead fitting and on one side attach a fitting and some aluminum fuel line that is 3/4 the length of the depth of your tank. This is the proper way to return it. If you look at all the quality tanks and or hats they have this feature.

I'll try to dig up some pics

 

[dieseldazzle]

I should say that you SHOULDNT just dump fuel (especially on efi cars with return style system) back into the tank.

 

[dieseldazzle]

If you look closely at both of these setups you will see the return side.

FYI I have first hand experience with both and the tanks inc deal is great. You do the measuring and cutting on the return.

Also FYI aluminum 1/4npt to -6 an fittings suck I had leakage with all then I went to steel (into steel pickup) and problem went away

 

[doublekrossd]

Unfortunately, I won't be able to get my hand inside the tank to tighten the nut on a bulkhead fitting. I'm gonna have to find a way to weld a tube onto the bung then weld the bung to the tank. I guess I've never heard of not being able to just dump fuel back into the tank, but I'll take you guys word for it. How would it be much different than just filling the tank?

 

[not so famous bob]

Unfortunately, I won't be able to get my hand inside the tank to tighten the nut on a bulkhead fitting. I'm gonna have to find a way to weld a tube onto the bung then weld the bung to the tank. I guess I've never heard of not being able to just dump fuel back into the tank, but I'll take you guys word for it. How would it be much different than just filling the tank?

put a new outlet for the new system. return fuel into a new , bigger stock pick up, cut the filter off and use the bigger-new suction tube for a return. it will be fine. I WOULD PUT THE NEW FITTING IN THE BACK OF THE TANK, DOWN LOW, AND THE PUMP BEHIND THE TANK. high as possible for road clearance. you wont be able to get it high enough to mess the draw up.

 

[ykf7b0]

Unfortunately, I won't be able to get my hand inside the tank to tighten the nut on a bulkhead fitting. I'm gonna have to find a way to weld a tube onto the bung then weld the bung to the tank. I guess I've never heard of not being able to just dump fuel back into the tank, but I'll take you guys word for it. How would it be much different than just filling the tank?

I installed a bulkhead fitting by drilling. I located it in a position I could start the nut on the inside with my longest finger and get a wrench on it too. Good luck!!!

 

[ykf7b0]

It was 1/2" also. The return really stabilized my fuel pressure and cut alot of the noise on an already quite Mallory 140 Series pump.

 

[oldmanmopar]

we cut a narrow them. go for it. Its only a tank.

 

[Yatzee]

I'm upgrading my fuel system this year to an electrical pump (A1000), big -10 lines, and a return style regulator. I have a 1/2" pickup and a new stainless tank. How have you guys plumbed in your return line? I thought about putting a sump in the tank and returning through the sending units pickup tube but something about cutting up a perfectly new tank doesn't appeal to me. Then I thought about just welding in the appropriate sized bung into the upper part of the tank to install a regular AN fitting. Any advice or ideas? Thanks in advance guys!

If you give it a bit of thought, you can reach through the hole for the sending unit by hand or with a large wrench. Give a bit of thought to where you mount the bulkhead fitting - directly below and slightly off to one side of the sending unit opening.The internal nut is going to be in the 3/4 - 1 inch range and a wrench for that size is fairly long. That's how I did it. I soldered a section of 1/2 inch soft copper into the bulkhead fitting and bent it by trial and error, each time setting the fitting in the newly drilled hole. When satisfied with the outlet position, I started sliding the copper tube through the hole, whilst at the same time feeding the inner washer and nut over the tube to thread on the bulkhead inside the tank. I then tightened the inner nut with a wrench, through the hole for the sending unit and held the fitting on the outside with a second wrench. Ratchet wrenches are perfect where space and movement are limited. My inner tube was 18' long and shot towards the rear against the left wall of the tank.

 

[65hemi]

My 1/2" sending unit had an extra tube that I removed and enlarged the hole. I installed a new bung and ran the return line through that.