Return line to fuel tank

[DoubleV]

OK thinking ahead about the strong possibility of needing to upgrade my fuel system. Currently just running a stock Carter mechanical rated at 120gph. Not certain this will reliably feed my Qjet all the way down the 1/4.

Lots of options available, some better than others. The absolute best way of course is to run an in the tank electric with a regulator. Of course that's the most expensive and the most PITA way to go too.

One thing that concerns me is the return line being too small. So my question, can't you use the return line AND the vapor return line? This would save a ton of hassle bending a new line which I would probably never get bent right....

 

[Fox80]

What I am doing with fuel injection is running an external electric fuel pump, a three pipe sender, using the "vent line" that originally ran to the vapor canister as the return line. I then used the third pipe on the sender for a vent with a mount above the trailing arm mount next to the body in the rear of the car

 

[455'ed80Regal]

^^^^What he said. Use the 5/16 evap line as your return line and you should be good to go.

 

[DoubleV]

Using the vap return line ( since it's bigger than the fuel pump return line ) seems like a no brained to me as well. Then I read about how Joe Blow had to bend his own line because the factory return line is too small and I start to wonder.

 

[ZZ4CutlaSS]

Only issue I see with using a return line that originally was used for the vapor canister system. Is your fuel tank will have no way to vent and it will build excessive pressure. I went thru this a few years ago, even tried a vented gas cap with no luck.

 

[pencero]

If you pressurize a tank that was not designed to be pressurized and it's not baffled you're supposed to take the gas cap off so it releases pressure somewhere else. Something has to give, duh. If anything buy a newer style gas tank w baffled so it's done correctly instead. If you don't, you could blow apart the gas tank or have reliability issues because of inconsistent pressure. Plastic gas tank is better psi. Some Fleetwood cadillacs have the plastic replacement gas tank kits if you can find one. That model has the fill tube behind lic plate same thing as cutlass / mc. Without a new gas tank the electric fuel pump is only a recipe for short term reliability. You could build the whole setup in a gas can and only put miles on it when you're racing and use a battery tray setup to secure it somewhere, then use the mech setup daily otherwise. Lots of people do that around here so they can daily drive w/o putting miles on their expensive setup. Certain gas can brands are made of thicker plastic than others and effective at holding enough psi to support 1/4 mile runs. Then all you do is drill out the hole for releasing pressure near the handle w/ a small screw and put a valve there so you can set the pressure analog style. Of course I did all that w/ a really small electric pump. It happened to fit this particular pump like a glove which was a mere coincidence. A great coincidence for me since we didn't want to redo the gas tank on that car but did just want to do some runs w it and then we just switched it back to the stock after that for mileage again. It took about 10-15 minute to switch back / switch forth. It just took a few test runs at a 'track' (an abandoned subdivision) to get all this working correctly and maybe 2 hours then we had a decent car. The batter tray we used still had room for 1 battery and we wired a extra 1 into the system so that the fuel pump would have power from a very close source instead of power comes all the way from the battery up front. That was the key benefit to this system. When power has to travel really far to push electric pump thats not ideal.