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Technical Installing fuel lines

Discussion in 'Traditional Hot Rods' started by terry k, Jan 21, 2020.

  1. Bandit Billy
    Joined: Sep 16, 2014
    Posts: 12,286

    Bandit Billy
    ALLIANCE MEMBER

    These were stainless clamps that I used on my roadster to hold the fuel and return lines to the rail. They look nice.
    upload_2020-1-22_12-9-39.png
    On SS line I like them because they polished up real nice. On the aluminum fuel line I showed earlier in my truck I used those adell clamps because I thought they would protect the line better and I had them lying around. Mostly because I had them lying around. @31Vicky with a hemi are they really that nasty?
     
    ekimneirbo, olscrounger and Blues4U like this.
  2. Idk man.
    They make them every day, they sell them by the boatload, They get used everywhere in a lot of different applications , And I’m sure the manufactures bank account and his house is a lot bigger than mine- so what the fuck do I know other than I don’t like them. It’s my opinion. Great treadmill parts.

    The holes are too small, not really wide enough to drill bigger holes and they are made out of thin stuff, some have extra thickener tab spot welded on that falls off, they look like crap right out of the box (probably my own issues) and look really crappy after some weather exposure.

    I think any OEM line clip set from the reproduction places is way better. Mopar are clean and simple, GM will get you where you need . Don’t tell anyone but Sometimes I’ll Take a look at the high end euro luxury stuff to see other ways. Here’s a rubber isolated clamp set for Mercedes just as an example


    91A6244B-B386-4E3A-9BFB-B28146B52779.png
     
    Last edited: Jan 22, 2020
    -Brent- and VANDENPLAS like this.
  3. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 4,217

    ekimneirbo

    Here are some pics for anyone unfamiliar with the differences between 37 degree and 45 degree flares. 45 is used in a lot of plumbing fittings but can be made to work for fuel lines. Often you are stuck with the brass look on fittings. Using a 45 degree flare on the end of a tube will necessitate using a fitting that has some type of 45 degree flare inside. That often reduces the size of the hole the fuel or fluid flows thru. I believe using the non-flared 45 with compression sleeves around the tube will allow less if any reduction in flow . Using the 37 degree fittings is comparible to what the military uses and doesn't impede flow. Thats what they use in aviation and it works well. It really depends on how much flow someone needs. I always go with 3/8 and don't worry about having to redo it later. The cost between doing 3/8 and 5/16 is pretty insignificant. Also, if using 37 degree stuff, 3/8 is easier to find stuff for. I know I had a hard time finding sleeves for 5/16.....so when I found some I bought a bunch. I use them for a return line in an OT fuel injection system. Nuff said !
    37 Degree Flare x1.JPG

    45 Degree Flare x1.JPG

    Flare Splice.JPG
     
    deathrowdave, Baron and Cosmo49 like this.
  4. Baron
    Joined: Aug 13, 2004
    Posts: 3,636

    Baron
    ALLIANCE MEMBER

    I usually run 3/8 steel tubing in side the frame rails. Make it in two pieces with one line connector, so if need be, both lines can be removed separately. Use line clamps secure it to the frame. I put the inlet just in front of the rear A cross-member(right where the gas tank is located), and it exits under the right motor mount bracket with easy access to the fuel pump.

    Sent from my SM-G950U using The H.A.M.B. mobile app
     

    Attached Files:

    Last edited: Jan 28, 2020
    ekimneirbo likes this.
  5. manyolcars
    Joined: Mar 30, 2001
    Posts: 9,176

    manyolcars

    I use 3/8 stainless tubing too. When I got my 39 Ford pickup,it had copper tubing. The fuel filters stopped up frequently with a fine copper powder
     
    Baron, Special Ed and ekimneirbo like this.
  6. big duece
    Joined: Jul 28, 2008
    Posts: 6,830

    big duece
    Member
    from kansas

    Does anyone know if the flare fittings for Hilborn injectors are 37 degree like single flare or AN flare?
     
  7. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 4,217

    ekimneirbo

    AN fittings (as well as their industrial twin brothers JIC) are 37 degrees. I would expect that the Hilborn would use 37 degree fittings. Getting a handle on threads and fittings can be difficult because in addition to the basic comparison pictures I posted above, there are some variations in the shape of the flares used on tubing.
    First, just understand that the two most common ones people use on fuel systems are 37 degree and 45 degree.

    Newer OEM vehicles have their own system of push on connectors with o-rings used for fuel systems.

    Brake systems have some additional types of flares they employ. Don't worry about trying to learn about them until you need to work on brakes. It just somewhat confusing to discuss all of it at one time. Again, just try to get familiar with the (JIC) AN fittings.

    Something a lot of HAMB'ers might like. Discount Hydraulic has some good handy reference info for your shop.
    First they have a PDF file you can save to your computer or print out. Big Duece will be interested in pages 4&5.
    https://www.discounthydraulichose.com/mm5/thread_guide.pdf

    Additionally they have a set of very nice reference charts . These are large well made wall charts.
    https://www.discounthydraulichose.com/free-thread-id-guide.html
     
    Last edited: Jan 26, 2020
    Jet96 likes this.
  8. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,523

    Roothawg
    Member

    Timely thread. I was just researching tubing straighteners and stainless tubing. I was wondering if you guys used annealed tubing for your stainless? I really want laser straight tubing with minimal joints on my next build.
     
  9. Blues4U
    Joined: Oct 1, 2015
    Posts: 7,589

    Blues4U
    Member
    from So Cal

    The reduction in size in a fitting like that is really pretty insignificant. In effect it is a type of orifice, and will not result in a reduction in flow except in cases where the system is operating at the edge of of sufficient flow already. Most auto fuel systems supply far more flow than is needed for the application, with the excess often returned to the tank. This is why pressure regulators are needed. Now, if the reduction in diameter exists over a length of tubing that is different, that can result in insufficient flow, but that's not what we're talking about when discussing fittings. If your system is that near to the edge of insufficient capacity that a 45* fitting would cause a problem you should probably look at redesigning the entire system with more capacity in mind.
     
    2OLD2FAST likes this.
  10. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 4,217

    ekimneirbo

    There are several versions of tubing straighteners available and they are reasonably costly for what you get......but mine does a very good job. The same one is available at several sites so shop around. Can't remember where I bought mine.
    If you are going to use steel or stainless, get one of the flaring tools like I mentioned that flares eccentrically......they help a lot especially with stainless. ;)
     
    Roothawg likes this.
  11. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 4,217

    ekimneirbo

    The difference in diameter between the inside of a piece of 3/8 tubing (.300) and the fitting in question (.275) is .025 .
    If my calculation is right, that accounts for a 15% reduction in the flow area along with possible disruption of smooth flow caused by the reduction.
    Bends in the tubing and multiple fittings further work against flow. I just wanted Rodders who plumb their systems with pipe type fittings to know that they won't get full flow . Every homebuilt Hot Rod is going to have its own set of fuel system needs. Since Murphy seems to reside at my shop, I always find it prudent not to give him any unnecessary opportunity.
    If using AN (JIC) Fittings, I don't think AN makes 5/16" fittings.........but JIC does. So anyone wishing to run 5/16" fuel lines will want to check that out before buying their fuel line. I had good luck on the 5/16" sleeves at the following company on Ebay. https://www.ebay.com/usr/clearwaterhydraulicsllc?rksid=p2057872.m2749.l2754
    I could find all the other 5/16 components except for the sleeves. Wanted to use them for a return line . Its best to try to buy JIC stuff in semi"bulk" quanities. 16 (all they had on hand) cost me $16. Sixteen 5/16" nuts with the shoulder also cost me $16.
    The sleeve & nut for a 3/8 line came as a set from another vendor .https://www.ebay.com/usr/*jeremiah*?_trksid=p2057872.m2749.l2754
    A purchase of 20ea 3/8 nuts and sleeves cost me $40
    Now those are representative of what I bought. If you try buying onesy/twosey.........you'll spend way more as you find you need them. Sleeve Nut.jpg
     
  12. AZbent
    Joined: Nov 26, 2011
    Posts: 279

    AZbent
    Member

    A word of caution, if you are going to use the AN type fittings, don't follow the graphic in post #24. The nut is backwards. I saw it and just started to laugh. A coworker heard me and asked why I was laughing. I showed him the picture and asked him what was wrong, he spotted it in a about a second.
     
  13. Beanscoot
    Joined: May 14, 2008
    Posts: 3,053

    Beanscoot
    Member

    Dead straight lengths of stainless steel tubing are a common item in industry for use with Swagelok fittings. But I don't know if that grade of tubing is "flarable".

    Fuel flow in lines and through fittings and elbows is a peculiar thing. You can have 3/8 or 1/2 fuel lines and then it ends up at the carb where it goes through a pair of 0.097" needle and seat valves (Holley 600 cfm) or perhaps a 0.110" needle and seat in a 735 cfm Holley.
     
    57JoeFoMoPar likes this.
  14. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,523

    Roothawg
    Member

  15. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,523

    Roothawg
    Member

    I saw that. I thought it was my old man eyes.
     
    Hot Rod Grampa likes this.
  16. No, but when I’m making new lines I try not to kill the last bit dead flat. Leave that for the conformity of the seal.
    Joining new to old I’ve had to loosen and tighten the fittings repeating several time to get a seal.

    If you look at the mechanical attributes involved and simplicity of manufacture process especially the female side the ISO bubble is way way better.
     
  17. Y’all take this for what it’s worth ,
    I like stainless fuel lines, but I don’t like the flairs and fittings. A friend of mine lost a fresh Hemi GTX to a fire caused at a stainless fuel fitting. Shifting thru the remains it was hard to tell of the fitting gaulled, loosened or the inverted flair split. Those lines were purchased as a pre bent kit . Nobody thoroughly inspected those lines prior to installation, but good gravy everyone and their brother did seventy two times after the fire.
     
    reagen likes this.
  18. There are 5/16" AN fittings available; just kind of hard to find sometimes. Mostly used in aircraft O2 systems and NAA hydraulic systems.

    And about Adel clamps; if they are the good ones, you'll get 1 chance to get them compressed and get the washer and nut started on the bolt. Miss that chance and you'll have to let your fingers regain their strength before trying again... They do make tools that help with the installation if you have the room to get them in place.

    There is a place in Hell for people like Mr. Adel.
     
    ekimneirbo likes this.
  19. Roothawg
    Joined: Mar 14, 2001
    Posts: 24,523

    Roothawg
    Member

    I always either safety wire mine or use wax string to tie them until I get the screw or bolt started.
     
    warbird1 likes this.
  20. I used to run miles of that tubing at work with swagelok fittings, one time I took a piece home to try a flare. My tool wouldn't do it, the clamp wouldn't hold tight enough to push the cone in to make the flare.
     
  21. Beanscoot
    Joined: May 14, 2008
    Posts: 3,053

    Beanscoot
    Member

    The other option is to use Swagelok fittings as well....
    It's a great opportunity to spend more money on one's car.

    Of course it's also an idea to just use the tried and true inverse flare fittings and plated steel "Bundy" or Cunifer type tubing.
     
  22. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 4,217

    ekimneirbo

    I haven't used one but don't think I need one....so far. I spent quite a bit of money on good tools for bending and flaring. I notice on the pop up that they have a Fragola 37 degree flaring tool. They want $214 . I paid about $90 from Precision tube in Indianapolis I think. As for the flare smoothing tool, I figure if I have a problem I'll try my air tool with a sanding cone and a quick rub. I think for the most part you won't have a problem. The eccentric flare works the metal more slowly than one that just pushes the whole flare at one time. It helps prevent splitting. Stainless is harder to work than just steel or aluminum. It generally shows up when doing some form of double flare. When I started fooling with all this flaring stuff, I wanted to see how well it held and made a pressure testing fitting to test the fuel line before I installed it. To test the fittings themselves, I put them on a short 30" tube. Any loss of pressure would immediately be apparent on such a small reservoir. Put a 100 lbs of pressure in the tube and a week later it hadn't moved. Checked my fuel line and then put it back on the short tube and aired it up again. Six months or so later I picked it up and it was still over 95 lbs.
     
    Roothawg likes this.
  23. theHIGHLANDER
    Joined: Jun 3, 2005
    Posts: 10,245

    theHIGHLANDER
    ALLIANCE MEMBER

    I'm there too. I took a cue from Packard. Heavy sheet metal, bend over a tube, leave a tab, punch a hole, radius the corners a bit or shape the tab end to taste. I make several at a time but don't have anything to show a pic of. I said Packard because such a clamp is found all over the car, some double like the sheet metal one shown above. Anyone can use Adell clamps...:cool:
     
    31Vicky with a hemi likes this.
  24. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 4,217

    ekimneirbo

    Here is a little more info that may help HAMBers..........
    Above there are examples of the 45 degree Flare common to NPT (National Pipe Tap) fittings and flares.
    The 45 degree flare is a Double flare that is done in two steps . First the initial flare is made on the tube. Then a second operation is performed that folds the flare back on itself.......doubling it. That seats in a fitting that has a 45 degree flare inside for the tube to seat against.

    There is another flare that is called a Bubble flare. Basically its done like the double flare but the tube isn't pushed all the way back so it doubles. I have only seen these used on smaller tubes, so I don't know if larger (1/2") sizes are available. Let me know if there are larger (1/2") ones. I'll include a picture below so people can see what they look like. Also a chart that some might want to print out and stick on a cabinet door.

    Then there is the 37degree single flare used with a sleeve to push it against a 37 degree seat. These are AN or JIC.
    AN is a military Spec while JIC is the same design but in an industrial spec.....usually made of steel.

    DSCN1751.JPG
    Flare types 001.jpg

    Flare Chart.JPG
    Hope this helps some ............
     
    reagen likes this.
  25. Lil'Alb
    Joined: Sep 22, 2013
    Posts: 255

    Lil'Alb
    Member
    from brier, wa

    Last edited: Mar 18, 2020
  26. In tank fuel pump, Gates (Goodyear?) modern fuel rubber hose for about 20" to the 3/8 NiCopp lines (supply and return)running to the firewall area. Held to the frame with stainless line clamps. I do have a mid 90's Ford fuel filter in line with the Springlock fittings. From the hard line ends to the fuel log, ss braided teflon (or ptfe, don't remember) that also have the Springlock fittings on the log end.
    www.purechoicemotorsports.com in Lake Havasu has tons of specialty fitttings like adapters for metric to AN, and Springlock to AN. A few years back, I was there for a bunch of fittings I needed. They were out of one in particular, so he made me one while I waited as it was already programed into their NC lathe. Good people, know their stuff.
     
  27. Beanscoot
    Joined: May 14, 2008
    Posts: 3,053

    Beanscoot
    Member

    That brake supplier has a lot of good fittings, but it's kind of hard to find them on their site, and interpret the descriptions of those without images.
     
  28. hot 37
    Joined: Sep 7, 2012
    Posts: 6

    hot 37
    Member
    from Wisconsin

    GM is using plastic/nylon - found this out the other day, wife's car had leak on gauge floor. local garage fixed problem with plastic! Checked it out on E-bay and U-tube, latest new product. I installed it my 36 hot rod. ran one line through box frame to fire wall then 3/8 steel to carb.
    -
     
  29. Almostdone
    Joined: Dec 19, 2019
    Posts: 892

    Almostdone
    ALLIANCE MEMBER

    I did similar to LM14, but I used 3/8 steel ‘brake’ line from NAPA. Modern rubber hose from tank to pre filter, then electric fuel pump, another section of rubber hose (to reduce vibration and noise from the pump), steel line from there to a post filter, steel from there to pressure regulator near firewall. I’ll finish with a short section of rubber for vibration reduction, then steel from there to a firewall-mounted fuel block. I spaced the post filter and regulator at about the length of the tubing to result in as few connections and new flares as possible.

    Size dependent on fuel need. My brothers with drag cars used 1/2 inch. They also used flexible hose. I prefer solid on a hot rod, and it shows some workmanship (hopefully).

    Decent tubing bender and flare tool + a little practice beforehand = not too much in the bent tubing scrap pile.

    I used these clamps (come in different sizes, seem to hold well, look sanitary, affordable).
    https://www.speedwaymotors.com/Stainless-Steel-Single-Brake-Line-Tube-Clamps-Bag-12,1975.html
     
    Shadow Creek and wackdaddy like this.
  30. lostone
    Joined: Oct 13, 2013
    Posts: 2,820

    lostone
    Member
    from kansas

    I'm with 31vicky, don't care for alot of the line clamps out there.

    Like to find something small, hidden, and easily installed.
     

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