Closed Loop Return

[rcdallas]

I'm curios about using a closed loop return; hopefully someone will have some insight.

I can think of a couple such as closing the loop will increase the fuel temp at injectors; sending it back to the tank really isn't necessary.

Anyone know how much of a temp increase one would yield?

Would the extra increase of temp actually be harmful as far as longetivity on the fuel pump?

I went ahead and closed the loop on my super duty this morning and now after reading some recent posts, I wonder how well my factory pump will do on my current setup.

-Randy

[chopperbob]

I would also like to know. I have a 3 way valve on my return but still have it returned, hav'nt switched it to the filter yet, I guess
I'm waiting for something, but I dont know what.
Bob

[rcdallas]

From what I am coming up with it's probably a mixed issue speculated type thing. That or in layman terms it's a poor mans way of heating the fuel/oil.

I don't have hard apple to apple test data, but I believe I rose the temperature at the stock fuel filter 20 degrees closing the loop.

I am thinking the best way to find out is to actually see if the ford fuel pump has temperature ratings listed for it to determine the longetivity.

I am not sure why a return line even exists, execpt for gelling purposes of adding a little extra heat to the fuel tank.

I think it'd be a good idea to run a 3 port valve (ac-delco brand) on the return; that way when in a hot climate such as Phoenix you can switch it off, or if your in cold Michigan you can switch it on.