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Fuel system return line question #1475135 07/27/13 11:03 PM 07/27/13 11:03 PM
Joined: Mar 2004 Posts: 314 Medina, OH D dart440_72 OP enthusiast
dart440_72 OP enthusiast D Joined: Mar 2004 Posts: 314 Medina, OH	Hello all, I am gathering the supplies to change out my BG280 to a Holly Dominator fuel pump. I have never run a return style system. I will be using -10 for the feed, is it ok to run -8 for return? Thanks 72 Dart 500" low deck Indy SR heads. 10.40 @129 best so far

Re: Fuel system return line question [Re: dart440_72] #1475136 07/27/13 11:07 PM 07/27/13 11:07 PM
Joined: Jan 2004 Posts: 581 Hamiltucky R RBDuster mopar
RBDuster mopar R Joined: Jan 2004 Posts: 581 Hamiltucky	That is is what I used.

Re: Fuel system return line question [Re: RBDuster] #1475137 07/28/13 02:22 AM 07/28/13 02:22 AM
Joined: Nov 2009 Posts: 3,082 St. Paul , Mn. tubtar master
tubtar master Joined: Nov 2009 Posts: 3,082 St. Paul , Mn.	With my BG 240 , they recommend a -8 feed and -10 return. Who am I to question why ? That's what I did. It sort of makes sense , as the -8 should be able to supply plenty of volume for a small block single carb deal like mine and the return will not provide any restriction.....so I guess on paper , it's all good. The manufacturer should be able to provide requirements for their stuff I bet.

Re: Fuel system return line question [Re: tubtar] #1475138 07/28/13 03:04 AM 07/28/13 03:04 AM
Joined: Feb 2004 Posts: 4,501 Gainesville,FL G goldmember master
goldmember master G Joined: Feb 2004 Posts: 4,501 Gainesville,FL	Quote: With my BG 240 , they recommend a -8 feed and -10 return. Who am I to question why ? That's what I did. It sort of makes sense , as the -8 should be able to supply plenty of volume for a small block single carb deal like mine and the return will not provide any restriction.....so I guess on paper , it's all good. The manufacturer should be able to provide requirements for their stuff I bet. I run the same feed as return,less extra fittings and hose to stock. Makes since to me.

Re: Fuel system return line question [Re: dart440_72] #1475139 07/30/13 10:20 AM 07/30/13 10:20 AM
Joined: Jan 2003 Posts: 13,365 Marion, South Carolina [><] an8sec70cuda I Live Here
an8sec70cuda I Live Here Joined: Jan 2003 Posts: 13,365 Marion, South Carolina [><]	Aeromotive A1000 pump on my cuda w/ a -10 feed and -8 return. Heard the same things you have and was concerned my -8 wouldn't work...called Aeromotive and the tech guy said it'd work no problem. That was almost 4 years ago. CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax

Re: Fuel system return line question [Re: tubtar] #1475140 07/30/13 12:04 PM 07/30/13 12:04 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	Quote: With my BG 240 , they recommend a -8 feed and -10 return. Who am I to question why ? That's what I did. It sort of makes sense , as the -8 should be able to supply plenty of volume for a small block single carb deal like mine and the return will not provide any restriction.....so I guess on paper , it's all good. The manufacturer should be able to provide requirements for their stuff I bet. You always want the return line to be bigger than the feed line. You want zero back pressure on the return line. -8 feed and -10 return would be good. Keep the 90 degree bends to a minimum on all lines. Fastest 300

Re: Fuel system return line question [Re: Crizila] #1475141 07/30/13 05:03 PM 07/30/13 05:03 PM
Joined: Aug 2004 Posts: 721 Seminole County FL to Plymouth... Barry70GTX super stock
Barry70GTX super stock Joined: Aug 2004 Posts: 721 Seminole County FL to Plymouth...	Does the return at the tank need to be above fuel level? I've noticed that low pressure race setups are above and factory high pressure setups are below. Will a low pressure high flow race pump for non fuel injection work with a return in the middle of the tank? NMCA NSS 67 Coronet

Re: Fuel system return line question [Re: Barry70GTX] #1475142 07/30/13 05:54 PM 07/30/13 05:54 PM
Joined: Nov 2009 Posts: 3,082 St. Paul , Mn. tubtar master
tubtar master Joined: Nov 2009 Posts: 3,082 St. Paul , Mn.	Quote: Does the return at the tank need to be above fuel level? I've noticed that low pressure race setups are above and factory high pressure setups are below. Will a low pressure high flow race pump for non fuel injection work with a return in the middle of the tank? With no scientific evidence , I am going to say yes. Plumb it into the filler neck or top of the tank for the same reason as using a larger line. You don't want the back pressure that forcing returned fuel to the tank through 1/2 a tank of fuel would provide. If you're using a cell , there will be a fitting located where ? Yes....on the top. I put mine on the top front on the pass side because that is the side the return runs down. An oval track deal would want a little more thought than that.

Re: Fuel system return line question [Re: an8sec70cuda] #1475143 07/30/13 06:00 PM 07/30/13 06:00 PM
Joined: Jan 2003 Posts: 6,266 Renton Washington T Triple Threat master
Triple Threat master T Joined: Jan 2003 Posts: 6,266 Renton Washington	Quote: Aeromotive A1000 pump on my cuda w/ a -10 feed and -8 return. Heard the same things you have and was concerned my -8 wouldn't work...called Aeromotive and the tech guy said it'd work no problem. That was almost 4 years ago. Same way my car is, no problem on pump gas, race gas or E85. -Dustin 67 Dart, 9 second, 392" G3 Hemi 68 Barracuda 340 F/SA

Re: Fuel system return line question [Re: Barry70GTX] #1475144 07/30/13 06:07 PM 07/30/13 06:07 PM
Joined: Jan 2003 Posts: 13,365 Marion, South Carolina [><] an8sec70cuda I Live Here
an8sec70cuda I Live Here Joined: Jan 2003 Posts: 13,365 Marion, South Carolina [><]	Quote: Does the return at the tank need to be above fuel level? I've noticed that low pressure race setups are above and factory high pressure setups are below. Will a low pressure high flow race pump for non fuel injection work with a return in the middle of the tank? Mine returns through the factory pickup tube...below fuel level. CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax

Re: Fuel system return line question [Re: an8sec70cuda] #1475145 07/30/13 07:26 PM 07/30/13 07:26 PM
Joined: Jan 2003 Posts: 7,131 Amarillo, Texas BBR master
BBR master Joined: Jan 2003 Posts: 7,131 Amarillo, Texas	I had a -8 feed and -6 return (which worked fine for an EFI application) and could not get the fuel pressure below 12 psi. Ended up putting a dead head reg between the return reg and the carb to knock it to 6psi. Fuel still circulates and keeps the pump happy. It's a bandaid, but it works fine and was cheaper than buying all new line and fittings for the return line. Drag Week 2011 - 77th place - DD Drag Week 2012 - 2nd place SRBB N/A Drag Week 2014 - Kapooya RMRW 2018 RMRW 2020

Re: Fuel system return line question [Re: Barry70GTX] #1475146 07/30/13 07:57 PM 07/30/13 07:57 PM
Joined: Oct 2003 Posts: 7,506 Az Crizila master
Crizila master Joined: Oct 2003 Posts: 7,506 Az	Quote: Does the return at the tank need to be above fuel level? I've noticed that low pressure race setups are above and factory high pressure setups are below. Will a low pressure high flow race pump for non fuel injection work with a return in the middle of the tank? Yes. 7795830-fuelcell.jpg (24 downloads) Fastest 300

Re: Fuel system return line question [Re: tubtar] #1475147 07/31/13 11:02 AM 07/31/13 11:02 AM
Joined: Aug 2004 Posts: 721 Seminole County FL to Plymouth... Barry70GTX super stock
Barry70GTX super stock Joined: Aug 2004 Posts: 721 Seminole County FL to Plymouth...	Quote: Quote: Does the return at the tank need to be above fuel level? I've noticed that low pressure race setups are above and factory high pressure setups are below. Will a low pressure high flow race pump for non fuel injection work with a return in the middle of the tank? With no scientific evidence , I am going to say yes. Plumb it into the filler neck or top of the tank for the same reason as using a larger line. You don't want the back pressure that forcing returned fuel to the tank through 1/2 a tank of fuel would provide. If you're using a cell , there will be a fitting located where ? Yes....on the top. I put mine on the top front on the pass side because that is the side the return runs down. An oval track deal would want a little more thought than that. I had searched for an answer to that and found nothing on it. I have a car with a stock tank and plumbed the return at the sending unit. 3/8 fuel line with 1/2 return. It was working fine until I filled the tank up. The pump started surging after the fill up. It's a Mallory 140 pump. Looks like I'll be moving the return. NMCA NSS 67 Coronet

Re: Fuel system return line question [Re: Barry70GTX] #1475148 08/13/13 01:37 PM 08/13/13 01:37 PM
Joined: Feb 2003 Posts: 1,942 Metro Detroit OUTLAWD top fuel
OUTLAWD top fuel Joined: Feb 2003 Posts: 1,942 Metro Detroit	I meant to reply to this a few weeks ago. I just sumped my tank, didn't want my return to be below fuel level for obvious reasons. Welded a tube into the filler neck. Hogged out the pressure relief of the cap to make it "vented". works great so far with a BG220 pump. 1/2 SS hardline front to rear. 7812704-IMAG0586.jpg (29 downloads) Faster, Faster until the thrill of speed overcomes the fear of death... 71 Swinger - slowly collecting dust/parts 66 Belv. II - just a streetcar 88 Mustang - turbo LS beater

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