Fuel return line?

[Jasonm]

I'm at the stage of planning my fuel system layout and will be installing the EFII boost pump and prefilter, Red Cube transducer and Andair valve. I'm still undecided on whose fuel injection I'll be using but wanted to understand if I need to plan for a fuel return line. What are other builders doing?


Jason

[BobTurner]

Standard XIO-540 thru Vans...no fuel return line.

[N15JB]

If you use Airflow Performance injection system, return line is optional, but recommended for improved hot starting.

I have the return line with my AFP system, and use it with every hot start. Not sure what hot starts are like without purging, because I have never tried them with this engine, XIO-540 by Barrett.

[N427EF]

Install the plumbing lines and fittings for a return line no matter what your plans are at this point.
You'll spend less than $50.- in parts and a little extra work but your options
are now wide open.
Among other options you'll be able to set up a mogas fuel system that won't vapor lock.

[paul330]

Originally Posted by N427EF

Install the plumbing lines and fittings for a return line no matter what your plans are at this point.
You'll spend less than $50.- in parts and a little extra work but your options
are now wide open.
Among other options you'll be able to set up a mogas fuel system that won't vapor lock.

....... except Mogas is not approved for the IO540.......

[rleffler]

Like Jim, I have an Airflow Performance FI. The purge line is connected to a t connector at the right seat tunnel wall. You switch to the left tanks, turn the boost on, and warm fuel returns to the right tank. The nice part about this arrangement is that you don't have to plumb all the way back to the tank.

You can't beat the support from Airflow. Give Don a call and discuss your questions with him. I think you'll be sold after your done with that conversation.

[Jesse]

There are really a couple of options for a return line. One is to do as Bob said and just T it into a line from one tank or the other. For a purge line this works fine. The other option is to buy an double stack Andair fuel valve that returns the fuel to the tank that it is drawing from through separate lines. This is required if you are using the EFII fuel injection, which is constantly returning fuel while running. Of course, with the efii you would want two boost pumps and would not need the red cube.

[Walt]

I agree, install the plumbing back to the tank then its there if you need it.

Plumbing back to the tank also eliminates the need for any special "purge procedure" like having to remember to select a particular tank.

[daviid]

i am putting a return line in. i picked up some 3/8" tubing and I plan to run it in the tank all the way towards the fuel cap. I figured this will allow a few things. 1) any bubbles will rise out of the fuel by the time it gets to the fuel output & 2) it will allow the fuel to cool down as well.

are these issues now? i don't know but i figure it couldn't hurt.

[Jesse]

Originally Posted by daviid

i am putting a return line in. i picked up some 3/8" tubing and I plan to run it in the tank all the way towards the fuel cap. I figured this will allow a few things. 1) any bubbles will rise out of the fuel by the time it gets to the fuel output & 2) it will allow the fuel to cool down as well.

are these issues now? i don't know but i figure it couldn't hurt.

You just need to plumb it into the top half of the root rib. Bubbles will come out anyway and the fuel will cool down. You don't need to run it out towards the fuel cap.