Vapor/Fuel Return Question

[HDCharger]

I've got some questions on Fuel/Vapor Return.   This is on a 73 Charger.....Currently Setup:

The 1/4" Vapor return is running from the 4 port "can" in front and above the tank to the Charcoal Canister by the radiator, the two outlets that formerly went to the carb plugged.   I have the 3/8 sending unit with the return plugged.  3/8 line goes to a filter then to a Mallory 4140 on the frame rail at the rear and pushes fuel to the regulator up by the quick Fuel 950.  The return port on the regulator is plugged.  I am running about 6-7 psi out of the regulator into the carb.  Is this set up OK? 

If not can I use the 1/4" line and plumb it into the return port on the regulator and to the port on the sending unit?  What do I do this the vapor return in this case?  Thanks for the help.  Dave

[firefighter3931]

Sure, no problem running the mallory 140 as a dead headed unit but it will run cooler and make less noise if you run a return line. The return line needs to be the same size as the supply line so your 1/4in vapor line is insufficient. On a street driven car i'd opt for a full return system to make the pump run cooler and keep the fuel circulating. Less chance for vapor lock. 

On a track only car you can run the 140gph pump deadheaded no problem....heat soak on the fuel line is never an issue. 


Ron

[HDCharger]

 Thanks Ron.....   I will run a return line back to the port on the sending unit, do I leave the vapor line connected to the canister and does it actually do anything with the other two ports capped?

[firefighter3931]

You're welcome Dave   

When plumbing the return line back into the tank try to us a 3/8 fitting to reduce pressure. The return should be under the least amount of restriction possible. One way to do it is to remove the 1/4in return line nipple on the sending unit and weld in a 3/8 tube in it's place. This will keep fuel pressure from spiking and keep your pump happy 

The charcoal cannister is just emissions stuff...


Ron