With return, or not…..? That is the question

[Superbee Sean]

1968 Super Bee that will stick with a Carb, not F I. 3/8 sending unit with return, or 5/16 with no return……that is the question……

 

[moparedtn]

Nothing says you can't run 3/8" without a return. I am...

 

[MoparLeo]

Start and drive vs, start, warm-up, smell fumes....etc.

 

[hunt2elk]

3/8" line and no return is what I run on my strokers.....

 

[Kern Dog]

I had intermittent vapor lock and fuel starvation until I went with a Carter fuel pump that made 11 psi. I added a regulator that allowed 3-4 psi at idle and 7 at WOT. Everything over 7 psi goes to the 5/16" return line back to the tank.
Since then, this car runs fine even in 110 degree heat. I've driven it here in Sacramento in the summer and am amazed at how well it handles the heat. Zero vapor lock, no stumble, starts when hot and does not starve for fuel at WOT.
Good luck.

 

[moparedtn]

3/8" line and no return is what I run on my strokers.....

Yep. Can't say I've been experiencing any issues with cranking up (cold or hot), either.
I'd say that's as much to do with running alky-free gas as anything else.

 

[cosgig]

Start and drive vs, start, warm-up, smell fumes....etc.

I have the vapor separator on my car and have a lot of raw gas smell, are you saying that system could be the culprit? It wasn’t always like this, but it’s pretty bad now.

 

[Black_Sheep]

The GTX has had a 3/8” line with no return since I built it 23 years ago, no issues…

 

[Sixpactogo]

Main reason for a return line is to ease the vapor lock problem.

 

[Sixpactogo]

I have the vapor separator on my car and have a lot of raw gas smell, are you saying that system could be the culprit? It wasn’t always like this, but it’s pretty bad now.

You more than likely have a leak. Sometimes they are hard to find. I had a heavy presence of raw fuel and found a small leak at the fuel pump. Finally found it but it took some patience. It wouldn't leak at idle but would at fast idle.