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copper fuel lines

Discussion in 'The Hokey Ass Message Board' started by bodymanmp, Dec 14, 2010.

  1. bodymanmp
    Joined: Dec 2, 2004
    Posts: 1,656

    bodymanmp
    Member

    is it OK to use copper lines for fuel lines??????????
    like on a 3x2 set up??????????
    do you double flare them???????????
    want to use from fuel pump up
    what do the experts say??????????
     
  2. Engine-Ear
    Joined: Jun 12, 2008
    Posts: 706

    Engine-Ear
    Alliance Vendor

    Man, you used up your question mark quota for the year!

    I wouldn't use copper unless you double-flair it, but it's so soft that you'll probably compress the DF after a couple of removals-n-retightens and you may have leaks (bad).

    Try it, be careful and stay observant for fuel leaks!!
     
    catdad49 likes this.
  3. lowsquire
    Joined: Feb 21, 2002
    Posts: 2,567

    lowsquire
    Member
    from Austin, TX

    sure. I use the olive and compression fittings. this avoids having to flare it. only use copper between points that are fixed in relation to each other, if you have to go engine to firewall, use rubber or braided flexible line.

    [​IMG]
     
  4. TagMan
    Joined: Dec 12, 2002
    Posts: 6,294

    TagMan
    ALLIANCE MEMBER

    I would never use copper for fuel lines. Any vibrations work-hardens copper, making it brittle and prone to cracking. In the case of using it for a fuel line, that would more than likely cause a fire and burn your ride up (and passengers, if they weren't quick).

    In any event, pressure is low on a fuel line, so double flaring is not required. I've us3ed compression fitting on many, many cars, with no problems.
     

  5. thunderbirdesq
    Joined: Feb 15, 2006
    Posts: 7,092

    thunderbirdesq
    Member


    x2...

    I used the same fittings as lowsquire on my flathead.

    Only from the fuel pump to the fuel block and then to the carbs in short lengths. Worked great... For about 6000 miles. In the middle of a 600 mile road trip at a 3am fuel stop I noticed one of the fittings was weeping slightly. Tried to tighten it and it just got worse. Took it apart and the compression sleeve was loose on the copper line. Checked the others and they weren't far behind. Major PITA, nothing was open, I was in the middle of nowhere, it was cold, lol! Had to wait until 8am when the local parts store opened up. Sucked... I wouldn't use copper for fuel lines again unless it was a parade car or something. Cunifer is a good alternative that looks like copper and is more resistant to work hardening.
     
  6. KrisKustomPaint
    Joined: Apr 20, 2007
    Posts: 1,107

    KrisKustomPaint
    Member

    Every air compressor I have ever seen had a copper line running from the pump head to the tank, I'm sure some newer stuff uses rubber lines, I've never seen one of those fail and those things vibrate like crazy! i would think that they see a lot more vibration than an engine. Being fuel though I would check it on a regular basis for cracks, and use a soft copper for the lines.
     
  7. KrisKustomPaint
    Joined: Apr 20, 2007
    Posts: 1,107

    KrisKustomPaint
    Member

    Just out of curiosity, what grade of copper where you using?
     
  8. ChromePlaterJosh
    Joined: Feb 15, 2009
    Posts: 667

    ChromePlaterJosh
    Member

    FYI, you can get steel lines copper plated and have the best of both worlds.
     
  9. thunderbirdesq
    Joined: Feb 15, 2006
    Posts: 7,092

    thunderbirdesq
    Member


    Stock early ford fuel lines and fittings available from any restoration parts house.
     
  10. TagMan
    Joined: Dec 12, 2002
    Posts: 6,294

    TagMan
    ALLIANCE MEMBER



    Only difference would be that if the line cracked on an air compressor, it probably wouldn't catch fire.

    But feel free to use whatever you like. My comments were only my opinion and worth every penney you paid for it..............:rolleyes:
     
  11. Jeff Norwell
    Joined: Aug 20, 2003
    Posts: 14,809

    Jeff Norwell
    MODERATOR
    Staff Member

    There's the ticket!:)
     
  12. thunderbirdesq
    Joined: Feb 15, 2006
    Posts: 7,092

    thunderbirdesq
    Member

    I don't think so!



    These guys have cunifer tubing for those who want the copper look with more vibration resistance.

    http://store.fedhillusa.com/about-us.aspx

    Chromeplaterjosh's idea sounds quite nice too!
     
    Big Swede likes this.
  13. KrisKustomPaint
    Joined: Apr 20, 2007
    Posts: 1,107

    KrisKustomPaint
    Member

    Agreed...

    I'm no shining example of safety, and an admitted pyromaniac. Fires make for good stories. Heard a lot of stories about stombergs catching fire. A whole lot more than stories i've heard about copper lines causing fires. I'll probably run copper on my model A, but thats a long ways off.
     
  14. TERPU
    Joined: Jan 2, 2004
    Posts: 2,372

    TERPU
    Member

    Copper is just fine, But use the compression fittings and make sure you leave enough hanging out of the fitting to allow for proper flow and compression. Double flaring copper is a bad idea. It tends to stress alot easier and the folds are where it cracks typically on the seam. Single flaring copper is how it was done on older aircraft and an acorn fitting and nut is the fastening method. That way there's alot of surface area clamped down. Nothing looks prettier than 00 steel wool shine on copper fuel line.

    Tim
     
  15. JeffreyJames
    Joined: Jun 13, 2007
    Posts: 16,628

    JeffreyJames
    Member
    from SUGAR CITY

    Yeah they actually sell rolls of it too but it's expensive like $200 a roll! I'll probably have mine copper plated or chromed when it comes time.
     
  16. thesupersized
    Joined: Aug 22, 2004
    Posts: 1,367

    thesupersized
    Member

    I believe Mac's auto parts and/or Dennis Carpenter sell lengths of copper plated steel line, ...this will give you the look of copper line, while not having to worry about the line cracking due to vibrations. their prices aren't too bad.
     
  17. F&J
    Joined: Apr 5, 2007
    Posts: 13,222

    F&J
    Member


    You mentioned the acorn fitting..

    I had some NOS fittings from my Dads repair shop from the 50s. There were some fairly long, very tapered brass nuts for copper tubing. My guess is the the length of the fitting helps to support the line far away from the flare or that compression bead.

    The modern short brass nuts for the compression bead, seems to make the beads wear or crush the copper line if there is vibration.
     
  18. darkk
    Joined: Sep 2, 2010
    Posts: 456

    darkk
    Member

    I've used plenty copper line in the day...
     
  19. inlinr6
    Joined: Oct 27, 2009
    Posts: 344

    inlinr6
    Member

    keep a fire extinguisher close.
     
  20. thunderbirdesq
    Joined: Feb 15, 2006
    Posts: 7,092

    thunderbirdesq
    Member

    That's exactly what happened in my case. I don't like the look of copper lines enough to endanger my car and life over it. I like to drive it, not wonder if it's gonna burst into flames!:D
     
  21. J scow
    Joined: Mar 3, 2010
    Posts: 489

    J scow
    Member
    from Seattle

    Speaking from a automotive education "technical" standpoint... NO absolutely never!!!

    BUT!!! I plan to use them on one of my cars.... Some times its fashion before function.
     
  22. gas pumper
    Joined: Aug 13, 2007
    Posts: 2,957

    gas pumper
    Member

    up til way after WW2 when the AN became surplus and Aeroquip was availible resonable $, copper was on cars and trucks and buses. fuel, oil, water and air for brakes, too. I worked on a lot of late 40's, early 50's trucks and buses and even the lines from the chassis to the engines were hard lined in copper.

    Bendix fittings for air had super fine threads and real long nuts with compression fittings. Everything else was long nuts and flare joints.

    Very few stress relief loops, too. usually only on 1/4 and 3/16 lines. All the bigger stuff, just straight runs.

    I really don't know where the fear of copper comes from. I've replaced a lot more rotten steel lines than broken copper. Factory stuff became steel because they only cared about the first 3 years, then your on your own. Steel is a lot cheaper for them.
     
  23. F&J
    Joined: Apr 5, 2007
    Posts: 13,222

    F&J
    Member


    Yes. those short nuts are not the best.

    I am positive that Chrysler Corp used the long nuts on their hyd brakes starting in the late 20s, and they also used them on the oiling fittings and fuel fittings.

    But I have worked on same age antiques and some cars had short brass nuts, and most seem to leak...then crack when you keep trying to tighten them.

    Now That I think about it, the long ones are not for compression beads, just flared line. They can't be obsolete, because i think I've seen them in the last few years on other things besides cars.
     
  24. Wheelie
    Joined: Nov 26, 2008
    Posts: 234

    Wheelie
    Member
    from Dallas

    I have a natural gas line behind my house that has copper tubing running to my backyard grill. I assume this is just as or more than flammable gas so I don't think it matters what you run through it as long as you don't route it poorly or use crappy fittings.
    I think with the proper routing and fittings you should have no problem. Plus most of the old cars from the 60's i.e. corvette, had copper line running to the oil pressure guage and that runs at a higher pressure than fuel lines and they work fine. The all use a compression type fitting.
     
  25. FAA file excerpt
    This aircraft mechanic didn't have good luck with copper fuel line.

    The airplane was an experimental First Strike Bobcat built by the pilot, serial number 412. The registration number N412LF

    was issued on February 23, 1995.

    The pilot kept a logbook which he used to record his progress during the building of the airplane. The log entry on May 17,

    1995, indicates that an Airworthiness Inspector from the Federal Aviation Administration had inspected the airplane. The

    inspector did not issue a Special Airworthiness Certificate on May 17, 1995, but instead listed numerous items that needed to

    be corrected on the airplane before the certificate could be issued. On May 22, 1995, the pilot noted in his logbook that he had

    corrected two of the discrepancies involving the fuel line and carburetor. One entry stated that he had installed a rubber retainer

    over the fuel line. The second entry noted that he had installed a carburetor retainer that secured the carburetor to the engine.

    The logbook indicates that the pilot had completed all the corrections by May 24, 1995, and had written a letter to the

    Airworthiness Inspector informing him of the corrections. The Airworthiness Inspector re-inspected the airplane on June 21,

    1995 and issued a Special Airworthiness Certificate. (See attachments)

    Wreckage and Impact Information

    The Federal Aviation Administration inspectors reported that the airplane was destroyed on impact with the ground. There was

    no damage to the propeller and the propeller had stopped in a horizontal position. The fuel tank was ruptured with no presence

    of fuel in the tank. The fuel strainer contained approximately 1/2 cup of aviation grade fuel when drained. A continuity check

    was performed on the engine and it revealed that the engine rotated freely, had normal valve operation, and had compression

    on both cylinders. The magneto rotated freely and produced spark at each of the two spark plugs.

    The two spark plugs showed no evidence of excess fuel when removed. All control surfaces were found intact and found to be

    operational with the exception of the left aileron due to the separation of the aileron push rod mounting block.

    The inspection also revealed that the copper fuel line from the carburetor to the strainer was broken at the carburetor ferrule

    fitting
    . The fuel line from the carburetor to the firewall consisted of about a six inch copper tube attached to a flexible hose. The

    carburetor and copper fuel line were removed for analysis by the National Transportation Safety Board.

    An examination of the carburetor and fuel line was conducted by the Materials Laboratory Division of the National

    Transportation Safety Board. The inspection revealed that the copper fuel line separated in the area immediately adjacent to a

    ferrule nut. An examination of the fuel line revealed fine crack arrest markings indicative of fatigue fracture mechanism. The

    fatigue cracking originated at the outside diameter surface of the tube; however, due to the extent of damage, the exact

    position of the fracture origin(s) could not be determined
     
  26. dorf
    Joined: Dec 5, 2008
    Posts: 1,087

    dorf
    Member
    from ohio

    velly intelesting thanks all
     
  27. Wheelie
    Joined: Nov 26, 2008
    Posts: 234

    Wheelie
    Member
    from Dallas

    So he should get his fuel lines inspected by the FAA? :)
     
  28. shmoozo
    Joined: Aug 14, 2007
    Posts: 671

    shmoozo
    Member
    from Media, PA

    That sounds like a viable alternative for a guy who really, really wants to have fuel lines that look like they are made of copper.

    Would it make sense to form and fit the steel lines from the fuel pump to the carbs before you take them out for copper plating?
     
  29. Wheelie
    Joined: Nov 26, 2008
    Posts: 234

    Wheelie
    Member
    from Dallas

    Most likely the plating will crack and peel off if you bend it after plating. It's like bending tubing with chrome on it. So to answer your question, most definitely bend it and fully mock it up prior to plating.
     
  30. Drive Em
    Joined: Aug 25, 2006
    Posts: 1,748

    Drive Em
    Member

    The work hardening "myth" makes me laugh. Any metal - steel, aluminum, brass and copper will work harden if not secured correctly. Also, the dual inlet chrome lines sold for Holley carbs are chrome pated copper, and I am sure there are still a ton of those in use.
     

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