fuel return to sump?

[roadrunner451]

Has anybody tried running your regulator bypass fuel line to your bottom -8 fittings on your fuel cell (or sumped fuel tank) or should i drill a hole in the top of the fuel tank. I figured it would be much easier to run it to the bottom fitting ,but im not sure, ill be running about 6lbs of fuel pressure for a NOS set up THANKS FOR YOUR HELP.

[John_Heard]

Return it to the top of the cell is the best way.

[sunsation540]

i have always used the open pick up in the bottom of the tank the upper one for a vent, BUT HERE WE GO the fitting is a # 8 and i drill it out to 1/2 in di and use a 9inch piece of aluminum tubing pushed through it with a flair on the end to seal the fitting so the fuel slosh is not an issue if you don't run foam the fuel being returned in the top of the tank brings bubbles with at as well..ran a hilborn set years ago and learned the hard way.

[John_Heard]

I'd have to see it to believe it. You would think the people that would have the worst problems with this are the ones that are bypassing a ton of fuel, like Outlaw 10.5/Pro Mod belt driven alky. Everyone I've ever seen is dumping it back in at the top of the cell. Bubbles have a hard time getting to the bottom of a cell is my belief.

[John_Heard]

Just an example -

[sc racing]

This is not race related but we put a corvette LS2 in a 33 ford at work used a stock replacement fuel tank had the feed on the bottom and the return on the top.

[TubbedTruck67]

You always want to return at the top of the tank. Theres going to be bubbles no matter where its returned. Plus the fact that you dont want to return hot fuel about an inch from where you pulling cooler fuel.

[Stickshifter 55]

In theory the fuel returned to your tank should NOT be aerated in the first place. It is the returning fuel that is creating the bubbles and such it should be located as far from the pick up as possible. I have always run a bypass fuel system both with my carb set up and with my current fuel injection set up. I returned my fuel to the top mostly because it was easiest to do for me. If I ever suspected any bubbles being pulled into my fuel pump the first thing I would have done would have been extending the return with a tube to have the fuel return to the bottom of the tank. Keep in mind this could possibly stir up debris in the bottom of the tank and create problems you didn’t have before. Since I had no fuel issues I left it as simple as possible

[sunsation540]

keeping the inlet away from the outlet is why i use the extended tubing from the bottom never had a problem with a return system that had more than 2.5 gallon tank . the return in the top is not a problem as long as it is not over the outlet..as for the notice of mech belt driven pumps vers elec the elec runs wide open all the time.. the mech pump runs off engine rpm usualy 10lbs per 1000 so at idle most again most return over 2 lbs idle ck valve.. so only 8 lbs being returned as the rpm increases so does the fuel consumption the amount of return goes down then with the use of high speed bypass you can return at pre set pressures with jets installed in the return some where from .080 .100 for a high speed so put that jet size in a #8 line and the pressure goes way down.. alot of wording.. for top returns and bottom returns when properly installed will work.. note the return on a mech fuel injection is to sensitive to return in the bottom of the tank as the weight of the suspended fuel will cause it to run too rich at idle and cause the barrel valve to have no or little effect.