Fuel System Setup

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Jasonmiester

Jasonmiester

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I have screw questions about my fuel set up. Wondering if I can get some advice.


Heres my drivetrane
dual quads on a 5.7 hemi
A833
3.91 gears 8 3/4

So I purchased a new tank, new sending unit
New filter, and all new 3/8 line, trying to figure out the correct plumbing.

1. I have been reading on the return line... Is this necessary ?

2. Is ok to have a filter before the electrical fuel pump? High flow one, even with sock filter on sending unit? Will this create too much restriction?

3. If the return line is not used, can I plug the regulator return line?

So here's the layout, any suggestions are appreciated.

3/8 sending unit, to small amount of rubber hose, to high flow fuel filter to small amount of hose to pump. From pump to steel 3/8 line to regulator with psi gauge to carbs.

Thanks in advance.
 
Jasonmiester said:
I have screw questions about my fuel set up. Wondering if I can get some advice.

Heres my drivetrane
dual quads on a 5.7 hemi
A833
3.91 gears 8 3/4

So I purchased a new tank, new sending unit
New filter, and all new 3/8 line, trying to figure out the correct plumbing.

1. I have been reading on the return line... Is this necessary ?

2. Is ok to have a filter before the electrical fuel pump? High flow one, even with sock filter on sending unit? Will this create too much restriction?

3. If the return line is not used, can I plug the regulator return line?

So here's the layout, any suggestions are appreciated.

3/8 sending unit, to small amount of rubber hose, to high flow fuel filter to small amount of hose to pump. From pump to steel 3/8 line to regulator with psi gauge to carbs.

Thanks in advance.
Click to expand...

A few, not screw...
 
Jasonmiester said:
Is ok to have a filter before the electrical fuel pump? High flow one, even with sock filter on sending unit? Will this create too much restriction?
Click to expand...

It depends on the pump and the filter. ANY pump is especially sensitive to inlet pressure drop and restrictions because it is already at much lower pressure than the outlet. What pump are you using, and have you read up on the specs?

What pump are you using?

Jasonmiester said:
1. I have been reading on the return line... Is this necessary ?

3. If the return line is not used, can I plug the regulator return line?
Click to expand...

Depends on the regulator. If it is strictly set up that way then you need the return. That should be detailed in the regulator destructions. What specific brand/ model regulator do you have?

But a return is a GREAT idea in any case. I don't use a pump which needs a regulator, but I still use a return, just for fuel boil/ vapor lock prevention, using a fuel filter with a built - in return orifice. They DO work, and they DO help
 
I am using a pump set up from procomp electronics.
140gph Free flow, preset to 14psi,
Regulator is adjustable from 3-14psi
Filter is a high flow, not sure on microns, but it only has the screen, no element.

Pump http://store.procompelectronics.com/p-2023-140gph-black-electronic-fuel-pump.aspx

Regulator, mine has return though http://store.procompelectronics.com...e-fuel-pressure-regulator-red-non-return.aspx

Filter, can't find the same on their site, but this is their eBay listing
http://www.ebay.com/itm/PRO-FUEL-DE...r_Truck_Parts_Accessories&hash=item27bd69f0f5

I also just purchased my sending unit, which is 3/8 and only has an vent tube, Besides the out let. I have read on how some people have tapped a nipple for the return line. Is this safe and efficient? Thx
 
Donoo. None of that stuff is showing actual specifications. Pump pressure?? Back pressure of filter?? Just guessing
 
67Dart273 said:
Donoo. None of that stuff is showing actual specifications. Pump pressure?? Back pressure of filter?? Just guessing
Click to expand...

Yeah I dealt with this guy through eBay, he's local. Very pleasant to work with.
The pump is 14 psi, so that's why I have the regulator. Not sure what or how to tell back pressure of filter is... I was planning to run a filter before carb. Is having the filter sock, and 2 filters too much?
 
when I did my fuel system on the dakota, the pump company recommended a filter before and after the fuel pump. One was like a 10 micron the other was a 100 micron filter. I had to run a return set up with the regulator, I would have otherwise too because it helps keep the fuel cooler. I would say contact the pump manufacture and see what they recommend for filters.
 
You definitely should use a "strainer " before the pump, no tighter than 80 micron, 100 is preferred. Of course a filter after the pump of 40 micron or tighter. Do your self a favor too and install a cut off valve before everything for ease of maintenance down the road. Try to install the pump so the inlet is below the outlet of the tank - the more the better. Always use a regulator - even if the pump has one play it safe with another.

The return line ... you will get a whole host of opinions on this. It will depend largely on the pump you use (some have internal bypasses, some don't). If you have one with an internal bypass my opinion is that you can run it without a return with no ill effects. Your best bet is to check with the pump manufacturer to ease your concerns on using or not using a return line. I run a Holley HP series currently and Holley feels this pump is just fine without a return line. I do not use a return and have no issues with it even in 95 degree weather.

The big "albeit" - you need to make sure you size the pump for the application. Bigger is not always better. A performance motor uses fuel at a rate of roughly 2X its Hp in #/Hr. If you do the conversion this equates to about 0.08 gal/hr per HP. If you have a motor making 500 hp X 0.08 gal/hr = 40 gal/hour (at WOT). Most pumps are rated at a "free flow rate" which does not account for pressure (why I don't know since every system is pressurized) - and of course does not take into account line loss, etc.
The bottom line - I believe, you can safely run a free flow rate that is about 1.5 to up to 2X what your motor will need at WOT and at 5-7 psi pressure. If you run a pump that is significantly bigger than this you "need" in my opinion, a return line - but then you have to ask yourself why you are using that large of a pump... A pump that is too large will not only cost more, be more noisey but will also be putting out a large flow - all the time. At idle when you are not needing much for the motor that flow is going right back into your tank like a water hose, with all of the turbulence and foaming, etc..
 
inkjunkie said:
IF this were true care to explain why damn near every EFI vehicle has a return line? Keep in mind that an EFI system will run like hell with aerated fuel......A bit of info on pumps & filters from Aeromotive.......http://aeromotiveinc.com/category/technical-documents/
Click to expand...

It's all how the system is designed and set up. Depends on how much flow is returning, under what pressure, at what point in the tank it comes in, how tight the tank is to atmosphere etc. OEMs have engineers that design these systems properly. What I was trying to address is what I see alot of in the hobby with people buying overly large pumps and careless routing of return lines. A pump that is too large with no return will tend to be noisy and run warm compared to one sized for the job. Conversely a too large pump with a large return line that enters near the pump suction line is asking for problems.
 
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