Author Topic: Where to return fuel  (Read 14572 times)

Offline BK

  • Sr. Member
  • ****
  • Posts: 311
    • View Profile
  • Your Best Time: 8.45 / 5.30
  • Your Track: Empire Dagway
  • Your Vehicle: Late 70's FED
Where to return fuel
« on: January 26, 2015, 07:25:48 PM »
 If I run my return line on the top rail of my car it would need to rise up a couple inch's to go in the top of the tank. I'm thinking that's not good. It would still be lower than the pump and check valve.
  I could put a bung in the back of the tank and keep the line pitched down all the way. The pump and check would be a few inch's above the top fuel level. But the return line would be below the fuel level most of the time.
 The other choice would be to return it to the feed line to the pump.
 Thoughts on the best scenario or other ideas.

Offline Totally T

  • Full Member
  • ***
  • Posts: 147
    • View Profile
    • NDRL
Re: Where to return fuel
« Reply #1 on: January 26, 2015, 08:04:36 PM »
I had a manifold with one return going into tank. Fitting was higher than the pump.

I have since made a manifold that goes into the feed line to the pump that all the returns feed into...its below the pump.
Troy Wilson
Nostalgia Drag Racing League

Offline Spud Miller

  • Global Moderator
  • Sr. Member
  • *****
  • Posts: 332
    • View Profile
    • Fuel Injection Ent., LLC
Re: Where to return fuel
« Reply #2 on: January 27, 2015, 08:52:09 AM »

 No need to worry about keeping things running downhill. Pressure will get it all there. When pressure/flow stops, the check valve closes (it's supposed to anyway) and it's like putting your finger over one end of a straw. The fuel will likely stay in the line behind the check valve even if it is downhill to the tank.

 If it's your main check valve (with a pill inside), it might be nice to have it a bit higher than the level of the fuel just because you won't spill as much when you change the main pill.

 Returning fuel to the pump inlet is perfectly acceptable and can save you a bunch of hose. Sometimes the need to purchase fittings with return ports can cancel out any hose savings however.

 Spud

Fuel Injection Enterprises, LLC
     Mechanical Injection
     Magnetos
     EFI Conversions

dreracecar

  • Guest
Re: Where to return fuel
« Reply #3 on: January 27, 2015, 09:58:13 AM »
I have been running all returns into the inlet for years, never had any issue doing it that way
and the fitting to do that is only around $40

Offline coupemerc

  • Sr. Member
  • ****
  • Posts: 307
    • View Profile
  • Your Best Time: 3.86@188 (1/8 Mile), 5.97@233 (1/4 Mile)
Re: Where to return fuel
« Reply #4 on: January 27, 2015, 01:13:55 PM »
My fuel returns are connected back to the main fuel line. I have not run my car yet but I know that the two fastest J/F guys on the planet have been doing this with zero problems.

Offline George

  • Hero Member
  • *****
  • Posts: 518
    • View Profile
  • Your Vehicle: 1964 Mercury Comet Super Stock/ M automatic
  • General Location: Midwest USA
Re: Where to return fuel
« Reply #5 on: January 28, 2015, 11:20:23 AM »
My fuel returns are connected back to the main fuel line. I have not run my car yet but I know that the two fastest J/F guys on the planet have been doing this with zero problems.

What size is the hard line ? I 'm guessing it's #12 braided line? I am going to something similar on ours. It's the connection to the tank that may take some fabrication. I will probably use .035 SS. Thanks. George

Offline coupemerc

  • Sr. Member
  • ****
  • Posts: 307
    • View Profile
  • Your Best Time: 3.86@188 (1/8 Mile), 5.97@233 (1/4 Mile)
Re: Where to return fuel
« Reply #6 on: January 28, 2015, 02:58:07 PM »
George, you are correct. The hard line is 1" and it is broken up into several segments joined together by rubber hose. The braided hose portion of the main fuel line is #12. The returns are #6. Hope that helps. Chuck

Offline George

  • Hero Member
  • *****
  • Posts: 518
    • View Profile
  • Your Vehicle: 1964 Mercury Comet Super Stock/ M automatic
  • General Location: Midwest USA
Re: Where to return fuel
« Reply #7 on: January 28, 2015, 04:26:23 PM »
George, you are correct. The hard line is 1" and it is broken up into several segments joined together by rubber hose. The braided hose portion of the main fuel line is #12. The returns are #6. Hope that helps. Chuck

Thank you Chuck. I ordered 1" .035 wall 316 SS . What kind of hose and clamps did you use? I run a filter with a shutoff and will return to one end of it with # 6. Your ride is looking good. Please keep us posted. Thanks again. George

Offline Totally T

  • Full Member
  • ***
  • Posts: 147
    • View Profile
    • NDRL
Re: Where to return fuel
« Reply #8 on: January 28, 2015, 07:00:14 PM »
George I can get pics of mine tomorrow if it will help. I came off the tank with a -16 into the manifold which is just about a foot long. Another piece of hose mounts goes to the pump from there. If your tank has a hose bung, you can adapt to AN flare for ease if needed.
Troy Wilson
Nostalgia Drag Racing League

Offline George

  • Hero Member
  • *****
  • Posts: 518
    • View Profile
  • Your Vehicle: 1964 Mercury Comet Super Stock/ M automatic
  • General Location: Midwest USA
Re: Where to return fuel
« Reply #9 on: January 29, 2015, 04:17:12 AM »
George I can get pics of mine tomorrow if it will help. I came off the tank with a -16 into the manifold which is just about a foot long. Another piece of hose mounts goes to the pump from there. If your tank has a hose bung, you can adapt to AN flare for ease if needed.

Thanks Troy, on our FED we will have 6' of hard line from the tank to a large filter/shutoff. It will take some custom fabrication to connect the two and that is not a problem as Doug (driver) can make almost anything.  I am concerned about the hose material needed at both ends  Also I want to use something better than hose clamps to attach the hose. Thanks. George

Offline coupemerc

  • Sr. Member
  • ****
  • Posts: 307
    • View Profile
  • Your Best Time: 3.86@188 (1/8 Mile), 5.97@233 (1/4 Mile)
Re: Where to return fuel
« Reply #10 on: January 29, 2015, 10:13:53 AM »
George, I'll check out the hose and clamp type for you tonight ... or tomorrow at the latest. Work is presently getting in my way! I can tell you that the rubber hose and clamps were originally put on the car at N&P.

Offline Spud Miller

  • Global Moderator
  • Sr. Member
  • *****
  • Posts: 332
    • View Profile
    • Fuel Injection Ent., LLC
Re: Where to return fuel
« Reply #11 on: January 29, 2015, 01:48:50 PM »

 Radiator hose from the auto parts store works great. Many foreign cars use 1 1/4" and other sizes and have molded in bends that you can cut out and leverage. They're methanol and nitro proof but not gas proof. Some of the parts store hoses come with a spring molded in to prevent collapsing too.

 If you use worm-gear type clamps, it'll chew your hose up and eat into it. Using the smooth hose clamps (like some folks use for motor mounts on a dragster) work great. Hose shops usually have those in a bunch of sizes.

 Spud

Fuel Injection Enterprises, LLC
     Mechanical Injection
     Magnetos
     EFI Conversions

Offline George

  • Hero Member
  • *****
  • Posts: 518
    • View Profile
  • Your Vehicle: 1964 Mercury Comet Super Stock/ M automatic
  • General Location: Midwest USA
Re: Where to return fuel
« Reply #12 on: January 29, 2015, 01:56:43 PM »
Hey, thanks guys. George

Offline coupemerc

  • Sr. Member
  • ****
  • Posts: 307
    • View Profile
  • Your Best Time: 3.86@188 (1/8 Mile), 5.97@233 (1/4 Mile)
Re: Where to return fuel
« Reply #13 on: January 30, 2015, 07:27:07 AM »
George, The hard line on my car is a little over 10 feet long. It is broken up into 4 segments. The segments are connected together by rubber hose that looks to me like it is radiator hose. The only marking I could find on the hose was "25.4 mm ID" and the clamps are regular hose type. Chuck

Offline Totally T

  • Full Member
  • ***
  • Posts: 147
    • View Profile
    • NDRL
Re: Where to return fuel
« Reply #14 on: January 30, 2015, 06:45:40 PM »
Ive saw the radiator hose used as well as the stuff the pro teams used...Spuds correct as both will work but I would spring for the aircraft clamps.

Heres mine..

Troy Wilson
Nostalgia Drag Racing League