Breather/Inverted

Discussion in 'Pitts Miscellaneous' started by garyg, Feb 4, 2018.

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  1. Feb 4, 2018 #1

    garyg

    garyg

    garyg

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    So I have a Raven Inverted system but I don't think that the problem is necessarily from the Raven system. It seems pretty normal.

    The engine breather is a 1 inch straight nipple off the accessory case. Standard issue I am sure (size and angle). Which means the other end of the hose also needs to be a 1 inch nipple. I am attaching the oil separator to the right side of the engine like all of them I have seen.

    An AN842-16D (90 degree elbow) is readily available for 15.00 or so but I cannot use that one where I wish to place the separator as it hits the mount. I would have to go further forward but even there I may be dodging the mount. So I want to use a A844-16D (45 degree) but it turns out that is a rare and expensive part. I found new ones (some old stock) from 243 to 50 dollars. I found some as removed by one place that had 39 of them for 100 bucks each and one place that had 5 as removed for 20 each. So I have one coming. But....

    I ordered what seems to be the only hose choice (MiL6000D hose from ACS http://www.aircraftspruce.com/catalog/appages/mil6000.php?clickkey=7466) at 9 bucks a foot for the 1 inch ID. I have seen an older piece of this in the 3/4 variety and it seems flexible with an inner braided core and smooth exterior. The hose I received has a weird spiral cord on the outside and it has a very wide minimum radius as I cannot seem to get the radius needed without it attempting to kink.

    I cannot believe I am the first one to have this problem. Is there a better choice of hose? Aircraft or otherwise. I have found this at Summit:

    https://www.summitracing.com/parts/ppe-515101036

    any suggestions on this?
     
    Last edited: Feb 4, 2018
  2. Feb 4, 2018 #2

    Neil

    Neil

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    I use the Russell brand from Summit for everything hose related.
     
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  3. Feb 4, 2018 #3

    PittsDriver68

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    There is a 10 inch long spring that goes inside that breather hose to keep it from kinking. Aviat sells it. Don't have the part number handy. I will note that the spring needs to be stainless to survive all of the crud that a breather puts out. I think that the spring is 0.040 wire.

    My S-2A that mounts an IO-360-A1A has a straight fitting for the breather hose. With the anti-kink spring in the breather hose the turn towards the right side of the airplane is not a problem.

    Best of luck,

    Wes
     
  4. Feb 4, 2018 #4

    garyg

    garyg

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    I was thinking of an anti-kink spring but I figured on planes that would be unheard of to stick something like that in a oil hose. So I just looked at ACS for a spring and look what comes up:

    Since the Christen system only has size 10 hoses. Maybe Aviat has a bigger one? The -16 fitting on the engine would swallow a -10. The catalog at Aviat for the S2B shows AN842-12D, so they use only a 3/4 hose but they do not show a separate spring. The drawings for the S1-11B have a 1 inch breather pipe, same size as engine nipple. So I don't think they have a 1 inch spring unless the S2C gets a bigger one?

    I didnt find a useful Russell brand 1 inch hose. Only the PPE at Summit looks suitable (with unknown bend radius).
     
    Last edited: Feb 5, 2018
  5. Feb 5, 2018 #5

    garyg

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    Anyone else have a 1 inch breather nipple coming off the engine? If so, what hose are you using? No AN hose will work on this fitting unless the 0.875 can stretch to 1 inch (which I find very unlikely).

    I know all the Aztec engines have this size. Are these replaced with something smaller (-12)?
     
  6. Feb 5, 2018 #6

    Randy

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    Gary, I have the same problem you have. I am using 1" I.D. hose from Aircraft Spruce #6000-16. I have a 90* fitting on the slobber pot and I can make this hose work but it seems to be right at the limit before kinking. I would like to find something a little more flexible. I was hoping you would get the answer here and I would be home free :)
    Tonight I will search the planet for a spring that fits inside my hose or a more flexible hose.
     
  7. Feb 5, 2018 #7

    cwilliamrose

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    Can you change the fitting on the engine to accept a smaller hose? The S-1S plans refer to a "fitting for .75 I.D. hose" on the engine at the breather location. No part number is listed that I can find.
     
  8. Feb 5, 2018 #8

    garyg

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    ok. I can't believe we are the only ones. I am waiting for a couple of replies. I have some older 3/4 inch 6000 hose and it shows no sign of kinking at this angle. The new one is constructed completely different and it kinks on a whim. pretty much useless inside the cowling.
     
  9. Feb 5, 2018 #9

    garyg

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    Allen Barrett said I could change it but the drawings for the plane say 1 in tube down the fuselage. I wondered if it is a good idea to have 3/4 inch from the engine to oil separator and then 1 inch from there for 12 feet from the oil separator. Also, I don't think this stuff from ACS is capable of making the bend from the oil separator to the body tube. It is of poor design. Lycoming must feel that 1 inch is necessary for an I/O-540?
     
  10. Feb 5, 2018 #10

    cwilliamrose

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    You have to put the spring inside the hose or it won't work.
     
  11. Feb 5, 2018 #11

    garyg

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    Yeah, but finding a spring for a 1 inch tube designed for going inside it and off the shelf seems to be an issue in my looking.
     
  12. Feb 5, 2018 #12

    cwilliamrose

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    The S-2B parts book shows an AN840-12D fitting on the engine end of the breather hose. That, I believe is a 3/4" straight hose fitting. There's an Aviat P/N for the hose but no size is given. The breather fittings downstream of the pot are also -12 size. I'd go -12 myself since the S-2B is a known quantity. If the 1" aluminum line is already in the fuselage I might leave it and adapt to it between the pot and the firewall or maybe using the firewall fitting.
     
  13. Feb 5, 2018 #13

    cwilliamrose

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    You make a spring on a lathe with a bit of trial and error to get the size right.
     
  14. Feb 5, 2018 #14

    garyg

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    lathe? me own a lathe? and use it? and know what I am doing?

    I read somewhere that the 12 foot breather line in the fuselage must be 1 inch for a 540. So if I keep the breather in the fuselage, that will have to remain 1 inch.
     
  15. Feb 5, 2018 #15

    cwilliamrose

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    I think the S-2B has a longer breather than the S-1-11 but maybe not?

    Here a video on how it's done. We did it a bit cruder, we just fed the wire by hand. The way it's done below isn't much more work, you just need a plate with a groove in it. Any machine shop could do this and anyone with access to a lathe could do it, even with little skill on the machine;

    [ame]https://www.youtube.com/watch?v=b06f-zBFXOM[/ame]
     
  16. Feb 5, 2018 #16

    cwilliamrose

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    Here's a lathe-less method;

    [ame]https://www.youtube.com/watch?v=Us28iaPOitU[/ame]
     
  17. Feb 5, 2018 #17

    garyg

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    If I roll my own, what size/type of wire should I use and coil spacing?
     
  18. Feb 5, 2018 #18

    cwilliamrose

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    Wes mentioned the spring for the 3/4" hose being about .040" wire. I'd think for a bigger spring maybe .045" or .050" McMaster-Carr has a decent selection in 304 and a few sizes in 316. Don't get the soft stuff, that won't hold its shape, it's like safety wire.

    As for pitch, 1/4"-1/2 sounds about right. I'd use something similar to the 3/4" spring's spacing.
     
    Last edited: Feb 5, 2018
  19. Feb 6, 2018 #19

    acropilotbret

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  20. Feb 6, 2018 #20

    Randy

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    The results of last nights search - -
    Jegs / Earls / e9performance / ultrarev all have 45* fittings that would help get my hose around the corner.
    I also searched 1" auto heater hose and may have found a better solution on eBay. A 1" I.D. wire reinforced, flexible, coolant/heater hose. From the enclosed photo it looks to be much more flexible than what I have. Comes from England so it's sold by the meter and Euro but it is approx. $15 for 3 feet. I will probably order it today. I only need about 1/2 that amount so anyone that could use the rest let me know. Or, I can order multiple pieces and save on shipping.

    s-l500.jpg
     

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