is there a need for a fuel return line from regulator

[chevyart]

have a low 11 second 406 sbc and use a mallory 140 electric fuel pump running to front to a 2 port mallory regulator. one port to the carb line and other blocked off. everyone says i must have a return line back to cell by using the blocked off port. i have also been told that a return line is really not necessary with this 140 gal pump setup and a return line may actually hurt performance. what is right and when exactly is a return line needed thanks chevy art

[johnracer]

Your Mallory 140 pump has an internal bypass that negates the need for a return syle regulator. You can plug the bypass and run a return but you really don't need to......

Johnny

[cepx111]

x2

[chevyart]

if i ru n the bypass line back to the tank instead of just plugging up the extra port, will the be any performance loss(even a small loss) by doing this unnecessary step thanks art

[johnracer]

With your Mallory 2-port regulator, you should have 1 inlet port, 2 outlet ports, and a 1/8" npt port for a pressure gauge. None of those are return ports. If you unplug the other outlet and return it to the tank, you'll be dumping most of your fuel pressure and will definately lose performance.

I always run one outlet to each float bowl on a Holley.

Johnny

[Scooterz]

X2. I just did a return line on my pro-street car. You first need a bypass regulator specifically to complete a return line. The question is... do you need it? Why are you thinking you need a return line exactly? Is it a drag car only?

[chevyart]

thanks guys for all the replies. TO TELL THE TRUTH this is my buddies car and he will not listen to me he did all of the stuff i asked questions about(inmy name) now maybe he will disconnect it as one of you guys confirmed my suspicion about loosing performance by bleeding off vital pressure back to cell. he will see all these replies that you guys sent in thanks art

[rtm2964]

hey, art, i'm here