I just picked up an Earls 140 fuel pump for the truck and after a bit of research I'm thinking about doing a return style fuel system. Seems like it may have multiple benefits from what I've read. I'm still trying to work out the details though and would like to hear how you guys have your fuel systems setup, what specific components, line size, etc. you are using and what the respective ET or HP is. As always, appreciate the help. Feel free to post pics. -Trent

Before I went EFI, I used a low pressure return regulator, 3/8 supply 3/8 return, worked great

I followed the manufacturer's instructions , even though they didn't make a ton of sense to me. B.G. HR 240 pump.
-8 from tank to carbs , -8 to bypass regulator , which is past the carburetor and -10 return to the tank.
The pressure stays right where daddy likes it under load and not that I am at a level where it will make a big difference , but the fuel is always tank temperature , and doesn't head up sitting in the under hood area.
I insulated the lines where they are near potential heat sources , and I did that with my last deal that didn't use a return.
I never had a problem with re-starts or boiling fuel in that one either.

I used to run the Aeromotive 11203 "street rod" pump w/ -8 line from a sumped stock tank to a deadhead regulator. It worked great running mid 9s at 140 mph, but on the street I had vapor lock issues w/ pump gas. At the track I never had any issues w/ vaporlocking, just had issues driving it on the street.

Switched to the bigger Aeromotive A1000 pump w/ a -10 feed and used my old -8 line for the return. Obviously I used the matching Aeromotive return style regulator up at the carb. Didn't run any faster (didn't expect it to) but it did help a LOT w/ the vapor locking issues I was having before.
I've since added a fuel log w/ a total of 3 regulators for the nitrous. Very happy w/ this system.

I'm considering seriously changing mine from a dead-head to a bypass setup, but haven't nailed down the specifics. The way I've heard my Mallory 140 complain when the engine's been forced to idle for extended periods tells me something needs to change. A way to adjust the fuel pump speed to engine RPM / demand would be helpful, too, even w/ a dead-head regulator.

[quote=tubtar]I followed the manufacturer's instructions , even though they didn't make a ton of sense to me. B.G. HR 240 pump.
-8 from tank to carbs , -8 to bypass regulator , which is past the carburetor and -10 return to the tank.

This is what I use as well, except I replaced the BG pump with a Mallory 250 when it locked up at the strip. This arrangement works just fine for me with street / strip use.

Mark

I am sold on return style fuel systems for my usage/application (mostly street, track only when I can squeeze it in).

My Garbage currently makes just shy of 500 to the rear wheels, I'm using Mallory branded pump and regulator with
-8 AN braided hose to and from the regulator, -6 to the bowls. Sorry I don't remember the part numbers.
-10 would be preferable per the pump manufacturer but I didn't want to deal with the additional bulk.

I first prototyped it with the cheap Carter of the day/late 80s (4594? whatever the direct connection book said to get, is what I had),
I ran it deadheaded for a long time but then tried a rubber return line with about a .060" restrictor.
The difference was noticeable, the pump did not heat up anywhere near as badly as before on the street.

The next version had an upgraded pump and regulator but at first, I could only afford hard lines at the time.
I made the lines best as I could. I was quite shocked to find that on a 90+ degree day the fuel lines would feel cool to the touch, enough to "sweat".

Later I upgraded the electrical system to include a fuel pump relay instead of direct switch.
By then, I had used the system enough to be 100% sold on it.
After that the braided hose and all that came into the picture.

Do you need all this? I think a really simple deadheaded system is just fine for an awful lot of drag cars. Especially ones that show up
to the track on a trailer, where nothing is really allowed to get hot for any length of time.
(That's not what I have).

I assume you're describing figure #3 as referenced below. It doesn't make much sense to me either so I may call Holley tomorrow and ask a few questions about it for clarification unless it comes to me pretty quick. I'm also trying to understand why some systems utilize a larger return than the supply while others run the same or even smaller with a restrictor. I was original leaning towards an Earls 12847ERL regulator but need to do more research on all the details before I pull the trigger on one. In all honesty, I'm not sure that the buy in cost on that particular regulator makes a lot of sense unless I'm just set on having all Earls components. There's probably a better choice one way or the other. Just need to decide what that is.

Im 8 up 10 back to tank with reg after the carb. Mallory 140 with their regulator. Been running this setup on past 2 cars for 15 years. No other way I would do it

While you have a Holley tech on the phone, ask them why they still recommend power valves open at half the idle vacuum.

This is the correct way to do it. Return should be larger than the feed , reg before the carb .
This is how mine is done and as prescribed Magna.

Either figure 2 or figure 3 will work. We use both styles depending on what fits the best. Both styles seem to work just fine on the typical performance car. I've used both styles for EFI also.

For years and years i ran a blue, then when it became a 9 second car a Holley Black pump deadheaded.
Drove it a ton on the street and raced it a bunch at the track. Never a peep under any circumstances.
I finally cave to peer pressure( some of it on here... lol) and switched to a much bigger system that also was return style.
The car ran identically to how it did before.
Whatever you decide to do, if the car gets street driven, make sure whatever pump you run is designed for continuous duty use.
That isnt always the case. Check.

I used the Morosso log fuel regulator. I liked that the fuel was unrestricted to the carb inlets. once it reached 8 pounds the relief opened and the excess went back to tank (front mounted cell) steady circulating till full throttle.

This is the approach that I had in mind.

Makes no sense to me why the return line would need to be bigger than the feed line; there's already going to be a reduction in volume from filling the carb, so having it the same size should be sufficient... IMO.

EDIT: Not sure of the manufacturer, but here's another schematic that's similar to what I posted above.

Return line should be bigger than feed line so the the regulator does its job. An equal size return line can cause x amount of pressure by itself rendering the regulator useless

Placing the regulator after the carb insures fresh cool fuel at all times to the carb

Its not about the fuel system making the car faster. Its about the life of the pump. Not having a single fuel related issue when its 1 million degrees outside. There is always someone from Michigan that says its a worthless upgrade. But down in the south it's the best thing you can possibly spend an extra $100 on

I now like and use the Magnafiuel pumps on all my cars that need a good high-volume fuel system, I plumb them as instructed and have no more problems with fuel delivery
No need for a return line from the front of the car also

I've ran Holley Blue pumps and have the billet black on it now and have never had any issues in hot weather, yes it gets hot here in KY too. I had a junk Magnafuel 275 that was plumbed like the diagram Brad posted. It lasted about two years before a bearing locked up. After a complete rebuild it started leaking the first summer, junk.

That system should work just fine on most cars. I think that you could even put the regulator in the trunk next to the fuel cell and dead head the pressure line to the carbs and have it work okay. That is the way my Duster is setup and it works. Some people don't like the long dead head section but it is under pressure so it should be fine. Most OEM cars are that way, even the high performance ones.