Oil hose / inverted

Discussion in 'Firewall Forward & Fuel System' started by death trap, Mar 21, 2018.

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  1. Mar 21, 2018 #1

    death trap

    death trap

    death trap

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    Getting ready to install a Raven Inverted System . I’ve used Pre Made Fragola 6000 PTFE Hoses from Summitt Racing for Oil Cooler lines but can’t find any info on using them on suction lines . Anyone had an oil line collapse under suction ?
     
  2. Mar 21, 2018 #2

    Bond007

    Bond007

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    Yes,I have seen oil line collapse, reminder all three oil lines going to the shuttle valve are suction lines ,so be careful what u use .
    I personally like 303 stratoflex.
    Danny 007
     
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  3. Mar 21, 2018 #3

    PG-

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    Yes they can collapse, the teflon does not seem to bond to the outer part of the hose. There is a lot of suction at high RPM, remember, the oil pump moves oil based on RPM and a lot of it goes back to the sump via the relief valve. The pump still moves all that oil....

    The problem with this hose showed up as lower oil pressure at high RPM on one flight, and lower still on the next.

    IMG_7164.jpg
     
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  4. Mar 21, 2018 #4

    garyg

    garyg

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  5. Mar 21, 2018 #5

    PG-

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    Those are certified hoses, I will take a picture of the band and hose type tomorrow....
     
  6. Mar 21, 2018 #6

    garyg

    garyg

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    I looked up the specs on AE701(http://www.eaton.com/ecm/groups/public/@pub/@eaton/@aero/documents/content/ct_195961.pdf) and it has this note on one page: NOTE: Hose not intended for vacuum application use. See Mil-H-83797.
    Hoses that may see intermittent vacuum pressure require an internal
    support coil. Contact Eaton for additional information.

    I looked up Fragola 6000 lines and it has something that says min radius of 15 inches, which seem like an eternity. They seem to be very high pressure lines.
     
  7. Mar 21, 2018 #7

    death trap

    death trap

    death trap

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    Looks like they make some Springs that can be installed inside the hose . Dry Sump race cars have the same issue .
     
  8. Mar 21, 2018 #8

    PittsDriver68

    PittsDriver68

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    Christen originally tried using 601 hose and went back to Aeroquip 303/Stratoflex 111.

    I will note from practical experience that the oil pump is not happy if there is a spring in the hose that feeds it. Create turbulence in the flow.

    This is a case where going outside the proven path will likely make the project take more time before first flight.

    Best of luck,

    Wes
     
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  9. Mar 21, 2018 #9

    garyg

    garyg

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    Spec for the 303 10:

    Hose Inner Diameter: 0.50 inch
    Hose Outer Diameter: 0.92 inch
    Maximum Operating Pressure: 1,750 psi
    Minimum Burst Pressure: 7,000 psi
    Minimum Bend Radius: 5.50 inches
    Vacuum Service: 28 in/Hg
    Weight of Hose: .36 lbs/ft

    so pressure way up, vacuum way down (same as racing AQP) but an increase of bend radius over Racing AQP from 4.0 to 5.5 inches. So that could make it tough for some things. and you have to buy the mandrels for 303 but the non-Eaton aren't to bad a price.

    The drawings for the S1-11 use -303 from the brake lines so I bought the stuff and the fittings but the mandrels were very expensive and I didn't see the aftermarket mandrels so I switched to a different Aerquip hose.
     
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  10. Mar 25, 2018 #10

    PG-

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    I know this was called "crappy hose" in a previous post, and in those photos it looked pretty crappy!

    Here are a few more. In talking with the smartest fluids guy I know, "Vacuum Service: 28 in/Hg" is about the most you can get with a gas. However a fluid is a differant story, especially if the fluid is thick, like cold aeroshell 80. The limit on the vacuum is then when pump cavitation begins. With a gear pump you can really pull it down. He also mentioned that the collapse failure will occur on the inside of the bend, ours did, and the larger the diameter the more likely to fail. Another point is the teflon inner hose does not bond at all to the outer body.

    I was told to think about a drinking straw in milk verses a milk shake.

    I'll stop now...

    IMG_7518.jpg

    IMG_7519.jpg
     
  11. Mar 25, 2018 #11

    death trap

    death trap

    death trap

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    Fragola got back with me and recommended the 3000 hose (not the 6000 from summitt ) , also spoke with Tom at TS Flightines about some hoses . Interesting stuff .
     

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