I experience vapor lock in the summer and noticed that I do not have a fuel return line at all on my '78. Can someone show me photos or tell me how to setup a return fuel line please?

I did all the engine bay cooling techniques without any real help. I do run headers and a mechanical fuel pump still. I burned up one electric fuel pump so I may beed advise on that too if I ned to go that route.

I replaced the original fuel tank with a 38 gal one.

Thanks

 

I'm unclear on what you're planning to do? Run a mechanical pump and add a regulator and return line?

If so, you'll need to pull the sender from the tank and braze a 5/16 or 3/8-inch return tube. Orient the end of the return tube pointing away from the pick up to avoid introducing bubbles.

 

I am trying to fix my vapor lock issue. I do not mind adding an electric pump back but not sure how to set it up exactly.

 

Below is a simplified diagram. Yes, run a regulator. Your system will have a return port at the regulator which goes back to fuel tank.

 

Perfect diagram! Thanks a million! One more question, does the return line go back to the tank or just circle around the regulator?

 

Nevermind, I did not read what you said correctly.

Thanks a million

 

Here's a better diagram:

 

If you stick with the stock style mechanical pump a fuel bypass can help also. With or without a return style regulator.

As posted above first step is installing a 1/4", 5/16 or 3/8" return nipple in the fuel sender at the tank. Braze or solder. A good radiator shop can do it.

To run the bypass without a regulator, you "T" the line between the fuel pump and carb. Install an orfice in the "T" with .050" diameter and hook the return line to the "T" and route it back to the added nipple at the tank in a second fuel line. You are basically introducing a small leak back to the tank. The hole in the orifice is small enough that it shouldn't hurt fuel pressure but it will keep some fuel circulating to keep things cooler and also get any bubbles or vapor headed back to the tank.

If your vapor lock happens while running the bypass will help a lot. If it vapor locks only after stopping and heat soak, bypass may help but may not be enough.

 

Thanks guys. It does seem to vapor lock more when i stop but it does do it on super hot days just driving. Now i do tow a camper with this too.