EFI Return line location(s)

[luvbowties]

I've been experimenting with the Holley Terminator #550-405 system, and it is working well on our "trial-car". Now, I wanna put one on my '66 C10. Got a question/idea on modifying Holley's proposed fuel layout that would save me a ton of labor. Shown herein is a pic of Holley's proposed layout AND my proposed modification of their layout: I am hoping my proposal will work. Please look at the 2 and give me ideas, pros and cons, as to IF the change will work. The mod is simply moving the end of the return line [from the pressure regulator] from making it enter into the top of the tank(left picture), to making it enter into the line going from the tank to the fuel pump's pre-filter(right picture).

Thanks,
Sam

[Jeff La]

Generally the return is back into the tank to help cool the return flow before heating again through the pump. The closest to the tank you get the better if modding. I think it would probably work as long as you wouldn't let it idle for long periods of time which is when you recycle the most flow. Regardless you will be losing some cooling.

[66 C10 383]

I agree with the cooling of the fuel. Think of it this way, there had to be an advantage for the return to the tank rather than tap back into the main feed or the factory would have saved a good bit of money returning to a feed line.

Will it work? Yeah it should. Would it be better going back to the tank. Definitely.

[Captainfab]

I'm with 66 C10 383 here.

Yes it should work, but there is a better way to do it. There was a thread here a couple weeks ago about the correct position of the return line. I am of the opinion that it should return to the tank as far as possible from the pickup tube. If needed you can add another port to your tank without welding by using a bulkhead fitting.

Originally Posted by 66 C10 383

I agree with the cooling of the fuel. Think of it this way, there had to be an advantage for the return to the tank rather than tap back into the main feed or the factory would have saved a good bit of money returning to a feed line.

Will it work? Yeah it should. Would it be better going back to the tank. Definitely.

[Gumby]

feed it into the vent line[ enlarge vent inside ],
use a vented gas cap.

[Snailed]

That's not ideal but would probably work. I don't know that tank you have, but besides cooling the fuel, often the return flow is used to keep the sump full as well. On my truck I have the pump sitting in a 2 qt sump inside the tank that is kept full partially by the return flow. This is how many modern tanks are setup if they are not returnless.

I have routed some return lines into the fuel filler neck so the tank would not have to be removed. It works fine as long as you aim the flow back to the tank. You can also go into a vent line as mentioned or put a fitting into the level sending unit plate if you don't want to modify the tank.

[luvbowties]

Many thanks to each for the informative replies. I will be using all the info garnered here when I plumb the return. Definitely, it will NOT be as on the diagram I had tossed out for inspection, but rather all the way into the tank--probably into the fill pipe, as I try to visualize my present setup. A primary concern is being able to bypass having to drop the tank which would be a major/aggravating process due to many obstacles.

Thanks again for all the help.
Sam

[luvbowties]

To anyone who knows why and where: I notice my thread was "moved"; did I do anything wrong to cause this? If so, what can I do in the future to avoid such inappropriate action(s)? Also, where was it moved to.....(rather, to where was it moved)?

Sorry for violating any policies, unknown to me at this time, that may be responsible; I'm hereby attempting to learn and correct such actions. After all, it is from this forum that I learn soooooo many good and useful things. Please, please respond.
Thanks,
Sam

[chevy_mike]

Originally Posted by luvbowties

To anyone who knows why and where: I notice my thread was "moved"; did I do anything wrong to cause this? If so, what can I do in the future to avoid such inappropriate action(s)? Also, where was it moved to.....(rather, to where was it moved)?

Sorry for violating any policies, unknown to me at this time, that may be responsible; I'm hereby attempting to learn and correct such actions. After all, it is from this forum that I learn soooooo many good and useful things. Please, please respond.
Thanks,
Sam

I moved this thread as it was more related to an engine question, then specifically related to 60-66 trucks. Having a thread in the right area also will get you better replies and keeps from cluttering up forums with unrelated threads.

This thread is in the Engine forum. There are a lot of area specific forums (Suspension, Engines, etc.). Look around the whole site and you'll find all types of great areas. Also check the "Sticky Thread" area, there is a great FAQ thread which might be helpful for you.

[Gumby]

filler neck would work, id used a sealed gas cap in that case.

[luvbowties]

Originally Posted by chevy_mike

I moved this thread as it was more related to an engine question, then specifically related to 60-66 trucks. Having a thread in the right area also will get you better replies and keeps from cluttering up forums with unrelated threads.

This thread is in the Engine forum. There are a lot of area specific forums (Suspension, Engines, etc.). Look around the whole site and you'll find all types of great areas. Also check the "Sticky Thread" area, there is a great FAQ thread which might be helpful for you.

Thx, Mike, for letting me know what was going on, to where, and for the help.
Sam

[luvbowties]

Originally Posted by Gumby

filler neck would work, id used a sealed gas cap in that case.

Caught this last note too--thx for opinions.
Sam