Houston_t

I need to add a return line to my tank and was wondering if I could just use one of the vent tubes ? I have a 71 cutlass and it has 3 vent tubes built into the top of the tank.

MDchanic

If your car didn't come with a return line originally, why do you have to add one?

- Eric

Houston_t

Running a electric fuel pump and the regulator has a return on it

joe_padavano

The correct way to do this is to replace the sending unit with one that has the fuel return connection. An alternative in your case is to tee the return into the fuel line on the inlet side of the pump. You won't get the benefit of circulating hot fuel back to the tank but the electric pump will solve any vapor lock problems anyway.

oddball

Going into a vent line will cause a ton of cavitation in the fuel, as it'd be spraying into the top of the tank.
A different pickup (that properly discharges the fuel at the bottom!) would work. You could also weld/epoxy a fitting onto the bottom front of the tank.
I cut open my tank and welded in a baking pan (seriously!) to mount a Ford electric pump. Took lots of patience since the metal is so thin, but time, plus a final covering in epoxy and using a fuel tank sealer did the tricks.

Houston_t

I would had thought that going through the bottom of the tank may not had worked. I'm may just weld a fitting on the front lower as you suggested, it's a new tank so I'm not worried about welding on it. If I did go through the top could I just use a longer line that fed the fuel to the bottom of the tank ?

hookem horns

Get a sending unit with 2 lines like used on the stock big block cars, but does require dropping the tank. No big deal compared to welding the tank.
http://www.oreillyauto.com/site/c/de...1997&ppt=C0025

Houston_t

Thing is I just purchased the tank and sending unit, took a little over a week to get the sending uni shipped to my house so I figured I would modify mines rather than return it and wait for another one. I have a welder and steel 3/8 line sitting in the garage, I may just add a return line to my sending unit, gotta look at it when I get home to see if i have room.

joe_padavano

Again, if all you care about is giving the fuel bled off the regulator a place to go, it DOESN'T need to go all the way back to the tank, just to the inlet of the pump.

Houston_t

Thanks for the help joe, been doing so much reading up on this that I forgot you mentioned that. Think I'm gonna give your way a shot should cost me all of about 3 bucks.