Fuel system idea

68converted

Member

Nov 19, 2003

772

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Colorado

Feb 12, 2006

#1

• Feb 12, 2006

• #1

This is what I was thinking. Does anyone have any ideas, concerns, that could tell me if this will work.

http://i48.photobucket.com/albums/f210/68conve

 

Dark Knight

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Feb 1, 2000

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Chandler, Az.

Feb 12, 2006

#2

• Feb 12, 2006

• #2

OOPS... no photo...

 

68converted

Member

Nov 19, 2003

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Colorado

Feb 12, 2006

#3

• Feb 12, 2006

• #3

Lets try that again
View attachment 487590
http://i48.photobucket.com/albums/f210/68converted/Fuelsystemidea.jpg

 

68converted

Member

Nov 19, 2003

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Colorado

Feb 12, 2006

#4

• Feb 12, 2006

• #4

Maybe some more info. The main crux of the system is the "T" at the return line. One side going to "refeed" the pump when needed and when the "re-feed" is not needed, fuel continues to the tank. The reason for the "T" is that we have no baffles in our tanks, and I don't want to run a header tank.

 

iskwezm

10 Year Member

May 24, 2005

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Rowland Heights,California

Feb 12, 2006

#5

• Feb 12, 2006

• #5

so your pressure feed line goes to the engine then the regulator??????

 

D

darkhorse70

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Dec 7, 2000

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Austin, TX

Feb 13, 2006

#6

• Feb 13, 2006

• #6

I think your fuel pump will suck air from the "return" side of the tank, since the return line enters the tank at the top, above the liquid level. That would produce bubbles in the line going to the engine, causing it to run very lean and hot. This would especially be a problem at startup, before pressure has built up enough open the regulator bleed-valve.

 

Dark Knight

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Feb 13, 2006

#7

• Feb 13, 2006

• #7

http://www.barrygrant.com/bgfuel/default.aspx?page=85

 

302 coupe

Founding Member

Mar 2, 2000

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Macon, Ga.

Feb 13, 2006

#8

• Feb 13, 2006

• #8

looks like you're trying to regulating the return line, which is incorrect. Also appears that the return line is plumbed into the feed line, which is also incorrect. You need to regulate the feed line, and the return line needs to dump into the tank. I think you're trying to over-design it.

 

red65

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Apr 12, 2003

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Ann Arbor, MI

Feb 13, 2006

#9

• Feb 13, 2006

• #9

302 coupe said:

looks like you're trying to regulating the return line, which is incorrect. I think you're trying to over-design it.

Click to expand...

Regulating the return is OK for an EFI application which, I think, is what he's trying to do. However, the purpose of all this extra plumbing escapes me too...

 

Hardtop68

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Aug 23, 1999

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Wherever they need me

Feb 13, 2006

#10

• Feb 13, 2006

• #10

I think that DARKHORSE70 is correct... avoid adding that line that connects filter inlet to regulator outlet...

 

68converted

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Nov 19, 2003

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Colorado

Feb 13, 2006

#11

• Feb 13, 2006

• #11

On an EFI application, the return line is not pressurised, and the return feed actually goes to the drain hole. Sorry for that error in the drawing. The regulator holds a specific pressure of fuel in the line and returns what is not needed to the tank. The reason to "T" into the tank outlet line (in my simplistic theory) is that I am trying to avoid the "air sucking" problem with the non-baffled tank. At that point in the system, the line is still non-pressurized, so, all I am doing is providing another source of fuel to the inlet line of the pump. If the fuel is not needed it would continue on to the tank. Right?

 

68rustang

Active Member

Jan 17, 2003

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Cleveland, OH

Feb 13, 2006

#12

• Feb 13, 2006

• #12

Two reasons I can think of that you wouldn't want to do what you are showing.

1) Heat, the fuel is going to warm up as it is pumped to the engine and back. Sending it back to the engine without letting it cool down in the tank isn't the best idea.

2) Your pump will draw from whatever source has the least resistance. Having two inlets give you twice as many opportunities to suck air.

 

starchiefus

Member

Dec 17, 2003

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7

San Diego

Feb 13, 2006

#13

• Feb 13, 2006

• #13

Hi.
Read this article......
http://www.mgbconversions.com/techroom/MYMGB302Conversion/efifuelsystem.htm

Its what I'm doing for my Mustang EFI conversion using Megasquirt, your basically adapting a spin on fuel filter into a surge tank, so it will not suck any air.

Hope this helps./Steve

 

68converted

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Nov 19, 2003

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Colorado

Feb 13, 2006

#14

• Feb 13, 2006

• #14

In that example, the parts I have missing are the big fuel filter and a low pressure/highvolume primary pump. The part about the EFI pump not pulling fuel is BS though. I pulled my Bosch pump off of a wrecked 745 beemer. The pump was about 10 inches above the tank. All the specs sheet say that it will pull fuel from a source over 12 inches below and 18" away. Not so sure about that setup for safety sake. I got a lot of info off the bronco site and never saw that one. I will have to look into the idea though. Thanks much.