308/328 Cohline Polyamide Fuel Hoses | FerrariChat

308/328 Cohline Polyamide Fuel Hoses

Discussion in '308/328' started by 360modena2003, Mar 8, 2022.

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  1. 360modena2003

    360modena2003 Formula 3

    Jul 11, 2009
    2,438
    Hello,

    One of my lines is leaking fuel, any suggestions where the 2mm ID plastic fuel hoses can be ordered?

    I have only been able to find hoses in polyurethane with 3mm ID and 5mm OD.

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  2. waymar

    waymar Formula 3

    Sep 2, 2008
    1,354
    Northeast, PA - USA
    Full Name:
    Wayne Martin
    Try Bellmetric they list M2x4 in the fuel hose section....
     
  3. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,829
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Also, Global Metrics in Belmont, CA can supply the Cohline polyamide fuel lines (and fittings) -- no website so you'd have to call (650) 592-2722.
     
  4. 360modena2003

    360modena2003 Formula 3

    Jul 11, 2009
    2,438
    I did see those, but the walls would be considerably thinner at 5mm vs 4mm OD.

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  5. 360modena2003

    360modena2003 Formula 3

    Jul 11, 2009
    2,438
    Thanks, will do.

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  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,829
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
  7. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,608
    California SF bay area
    Full Name:
    Paul
    Wall thickness is 2mm on either 2x4 or 3x5
     
  8. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,829
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Your math is off -- the wall thickness is 1 mm on both: wall thickness = (OD - ID)/2
     
  9. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,608
    California SF bay area
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    Paul
    ha,ha right there are two walls ;-)
     
  10. 360modena2003

    360modena2003 Formula 3

    Jul 11, 2009
    2,438
    Yes, that is the issue, 1mm vs 1.5mm wall thickness is a considerable difference.

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  11. 360modena2003

    360modena2003 Formula 3

    Jul 11, 2009
    2,438
  12. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,608
    California SF bay area
    Full Name:
    Paul
    How are you getting 1.5 mm?
     
  13. 360modena2003

    360modena2003 Formula 3

    Jul 11, 2009
    2,438
    2mm ID + ( 1.5mm + 1.5mm ) = 5mm OD



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  14. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,829
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #14 Steve Magnusson, Mar 9, 2022
    Last edited: Mar 9, 2022
    That might be difficult to find. On the US TR, the smallest Cohline tubing size is 3x5 -- are you sure that yours is really 2x5? At 2mm ID tubing, the male barb (with say a 1mm thru hole) would be rather fragile and easily broken. What is the Ferrari part number of the line you need? Maybe Maranello Concessionaires could supply it?

    The 2x4 line would certainly work OK as it's good up to a pressure of 44 bar (and your Bosch CIS system is something like 5.5 bar).
     
    waymar likes this.
  15. 360modena2003

    360modena2003 Formula 3

    Jul 11, 2009
    2,438
    Yes, I am very sure, see attached pictures.

    Specially mentioned for K-Jetronic.

    Image Unavailable, Please Login Image Unavailable, Please Login

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  16. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,608
    California SF bay area
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    Paul
    On Belmetric the 5mm OD line has a 3mm ID, not 2mm. Wall thickness is the same on either - 1mm.

    Belmetric/hose/gasoline
     
  17. 360modena2003

    360modena2003 Formula 3

    Jul 11, 2009
    2,438
    Yes, and this is why it is not the correct fuel hose.

    See the pictures I attached, THOSE are the correct ones.

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  18. RodC328gts

    RodC328gts Formula Junior

    Aug 17, 2021
    458
    Mexico
    Full Name:
    Rod C
  19. 360modena2003

    360modena2003 Formula 3

    Jul 11, 2009
    2,438
  20. kcabpilot

    kcabpilot Formula 3

    Apr 17, 2014
    1,608
    California SF bay area
    Full Name:
    Paul
    Hmmm...okay well, I did my entire system a couple of years ago. I got it from unobtainium and Belmetric. I've got some leftover scraps and bits so I guess I could go dig it up and see what it is. I just don't remember any 2x6. Which line are you talking about?

    I'm just saying that many people like myself have completely redone the entire system and nobody, as far as I know, has had any problem getting the hose.
     
  21. pshoejberg

    pshoejberg Formula 3
    Silver Subscribed

    Dec 22, 2007
    1,828
    Denmark
    Full Name:
    Peter H
    I have shopped at cohpro.com many times for cohline piping for all my injected Ferrari's. Super shop, fair pricing and they stock the original fab and correct sized piping for our injection system. Take very good care of the fitting especially when removing the old piping (Use a heat gun) and buy a special tool for installation of the new piping. There is a guy here on Fchat that fabricates and sell a tool for that purpose (See pic below). Be aware you normally need two pipe sizes for a complete 308 installation.

    Best, Peter

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