Electric fuel pumps w return lines?

[Geo's66]

hey guys- do return fuel lines need to also have electric fuel pumps vs mechanical?

I've got the 600hp fast times motor running in my 78 Monte- but experiencing fuel boil I believe making it really difficult in traffic.. No return line at all now, mechanical pump in it now too..

Just curious if I go this route is it necessary.. I'm inclined to go that route as sometime in the next sour years probably EFI the setup anyway-

Thanks!!

 

[V8 Rumble]

I have the fitech efi and use the corvette fuel filter that has the the built in regulator and return. This has been working great!

https://m.summitracing.com/parts/wi...ZMRei-V8NqWt-QWjuBCR2dAVZVDruUN0aAgDzEALw_wcB

 

[drogg1]

It depends but generally an electric fuel pump will generate a fuel pressure too high for a carburetor and so you will need a fuel pressure regulator. It is best practice to run a return line with this to return the bypassed fuel from the regulator to the tank.

 

[565bbchevy]

First I am curious as to what mechanical pump you are running?
I run a Paxton 300 electric pump in my Monte it has a bypass that comes off the pump and goes into my fuel cell and up front I have a BG 4 port regulator that is set for carb pressure, I have never had a fuel issue even sitting in Dream Cruise traffic (not moving).

 

[Injectedcutty]

It depends but generally an electric fuel pump will generate a fuel pressure too high for a carburetor and so you will need a fuel pressure regulator. It is best practice to run a return line with this to return the bypassed fuel from the regulator to the tank.

That is unless he gets a holley "red" pump which is electric and maintains carb fuel psi at 7lbs. I ran one on a relay for years before I efi'd my sbc and it never let me down!

 

[Geo's66]

I don't know what's on motor now- will find out but it is mechanical.. Just don't have build sheet w me.

Graham Jones built an awesome Dart small block w rollers, etc..

We suspect the fuel boil IS the issue- I'd assume I'll go EFI anyway(should've 1st), so I'll get the electric pump while having the return line from in-line hooked up..

You guys also use phenolic spacers or should the return line be sufficient?

 

[Geo's66]

First I am curious as to what mechanical pump you are running?
I run a Paxton 300 electric pump in my Monte it has a bypass that comes off the pump and goes into my fuel cell and up front I have a BG 4 port regulator that is set for carb pressure, I have never had a fuel issue even sitting in Dream Cruise traffic (not moving).

Tell me about this system?- I'd like to learn which is best way to go and do this once if possible- thanks

 

[565bbchevy]

Tell me about this system?- I'd like to learn which is best way to go and do this once if possible- thanks

You can build a nice dependable carb fuel system but if you plan on going EFI in the future you would basically be wasting your money.

 

[fleming442]

I disagree. The only money "wasted" is the regulator, and if you buy the right one, all you have to do is change the spring from carb to EFI.
I put a Spectra Premium tank with in tank pump in the red car with a Mallory regulator. I ran -8 supply and -6 return. The problem came when I couldn't get the pressure below 9psi. The return in the sensor was too small, so I teed off to an unused vent port. It works well, and if I ever put a Sniper or FITech on, all I have to do is pull the regulator.
I'm using a GN sender and pump on the Pig project with -6 supply and return.

 

[565bbchevy]

I disagree. The only money "wasted" is the regulator, and if you buy the right one, all you have to do is change the spring from carb to EFI.

I was referring to a set up like mine since that is what the OP asked me about, which is an external mounted electric pump that is dedicated set up for a carburetor and can not be used for an EFI system so I feel it would be a waste of money if EFI is in his near future.