Let's talk FUEL LINE sizes

[Detonator]

I'm running 3 94s on a Nailhead, which need 2.5 to 3.5 PSI fuel pressure. Per the Bishop/Tardel book, it looks like I should be running 5/16 line. Here's my question: Can I run 3/8 line from the tank -- to the fuel filter -- to the fuel pump (Carter P4070) -- to the pressure regulator (Holley 12-804) -- to the fuel block -- and then step down to 5/16 line out to the carbs? I probably shoulda listened better in Physics... http://www.jalopyjournal.com/ubbthreads/images/graemlins/tongue.gif

[AnimalAin]

Yes. And furthermore, you will have enough capacity that if you change the setup to something else later, you can still hack it. I would never run the whole car in small line; just one more restriction if you decide to make more hp later.

[Detonator]

Thanks -- I kind of thought so. The filter unit, pump and regulator all take the larger fittings, it'll save me having to step everything down to 5/16 -- and avoid the possibility of more leaks http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif

[fab32]

I use a minimum of 3/8" from the tank to the engine compartment. That way there is no chance of low fuel supply. You can then step it down to whatever you need in the engine compartment. In rare incidences you might need a 1/2" supply line but it would only be when running dual electric fuel pumps,a tunnel ram with 2 large carbs on a big cube engine while drag racing.

Frank

[hotrodsnguns]

You can but after running the larger 3/8 line all that way, Why step it down??

[AHotRod]

YES!
Just be sure the pump is near the tank.