installing air intake to servo/Firebolt nose bowl

Discussion in 'Steen Skybolt' started by taff, Jun 17, 2018.

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  1. Jun 17, 2018 #1

    taff

    taff

    taff

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    I am waiting for a lot of things to do with the Lycoming engine.
    So I thought I would start the job of getting fresh air into the fuel injector servo.

    Taking a look at what I have to work with, maybe someone has gone this way in the past and could share with me some ideas/photo's.
    Attached, a couple of photo's to show what I have.
    All ideas and pix greatly appreciated.

    DSCN8134 (1280x960).jpg DSCN8138 (1280x960).jpg
     
  2. Jun 18, 2018 #2

    mjk51

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    I fabricated a square flange. A short piece of SCAT tubing. A round flange bolted to the Bendix. The square flange has slightly tapered sides and it pockets nicely with the square opening on the nose bowl. I did not attach the square flange to the nose bowl. It has a goodly amount of tension and should float with any cowl/engine movement.I looks like you have a 90 degree adapter on your your servo. A 100 degree angle adapter might give you better alignment. Or perhaps a spacer between the angle adapter and the case.
    . Side.JPG front.JPG
    mount1.JPG
     
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  3. Jun 18, 2018 #3

    taff

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    Thanks.
    I like this idea. I have an aluminum plate I can cut down and drill to secure to the front face of the servo,
    I can weld on aluminum tube. This is a good start.
    Cheers.
     
  4. Jun 18, 2018 #4

    Vic Zubot

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    I used a Van's snorkel which takes in the air through a K&N filter in the cowl intake. Makes for a very clean front end.
     
  5. Jun 18, 2018 #5

    Vic Zubot

    Vic Zubot

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    IMGP6759.JPG IMGP6699.JPG IMGP6715.JPG IMGP6759.JPG
     

    Attached Files:

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  6. Jun 18, 2018 #6

    Vic Zubot

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    My Citabria uses a hose set up as in the previous post.
     
  7. Jun 18, 2018 #7

    taff

    taff

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    Thanks Vic.

    But I don't have the available space to install the filter there.
    A couple of photo's to show my space.
    One of yours for reference.

    IMGP6696[1].JPG DSCN6640 (1280x960).jpg DSCN6642 (1280x960).jpg
     
  8. Jun 20, 2018 #8

    taff

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    So far, I have come up with 2 possible options to install a air filter for my servo.

    Option 1 is an intake tube and attach a cone shaped K&N filter.

    Option 2 is build a frame that is riveted to nose bowl. Then make a flat filter that is held in a removable support. This is then screwed onto the frame, very much like the Citabria.
    Behind the filter I will still use the intake tube.

    I am still looking for and would appreciate other ideas :)
    DSCN8147 (1280x960).jpg DSCN8148 (1280x960).jpg DSCN8146 (1280x960).jpg DSCN8150 (1280x960) - Copy.jpg
     
  9. Jun 20, 2018 #9

    PittsDriver68

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    Just be aware that all of the air that goes around your engine intake and under the engine will create pressure that defeats the flow through the cylinders, raising the CHT's. So some sort of seal to prevent that flow will be needed if you have not already thought of it.

    Best of luck,

    Wes
     
  10. Jun 20, 2018 #10

    Cameron

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    Just a thought and I'm obviously biased...but it looks like you could do an arrangement similar to what the Eagle has. I like the flush filter frame the best of the two options that you showed...I just think it looks cleaner. But if you used it, and had a filter mounted to it, then you could also mount a rubber sheet (inner tube rubber works well) to the back side of your nose bowl, with an appropriately placed 2" hole in it. Then, you could have a tube mounted to the front of the servo that sticks through the 2" hole in the rubber sheet. This will provide the seal that Wes is talking about, and also allow for engine movement.

    Just a random thought.
     
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  11. Jun 20, 2018 #11

    taff

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    Thanks.
    I was thinking of the need for a seal, but haven't had ideas yet of how I am going to do it.
    I'm thinking about closing the area somewhat with fiberglass and then ?
     
  12. Jun 20, 2018 #12

    PittsDriver68

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    That's the challenge. The seal design needs to allow for the front of the engine to move 1" to 1 1/2". I am trying to figure out how to improve the S-2A's setup, which allows a lot of air leakage into the lower engine area.

    Best of luck,

    Wes
     
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  13. Jun 20, 2018 #13

    taff

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    1 and half inches, I didn't realize that much.
    So your thinking that there could be 3/4" movement on all sides of the tube?
    DSCN8147 (1280x960) - Copy.jpg
     
  14. Jun 20, 2018 #14

    garyg

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    It looks like the servo does not align with the nose bowl? all the ones I see appear to be symmetrical. Is there a reason for this offset?
     
  15. Jun 21, 2018 #15

    taff

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    You are correct.
    The inlet of the servo and the recess in the nose bowl are not in line.

    Only thing I can think of is that the original sump (that once held a carburetor) has the access point that unfortunately is not aligned with the nose bowl.
    I had to cut and weld an offset in the tube to find the center of the bowl recess.

    Who said this was going to be easy!
    It seams that I am jumping through hoops with many things. :rolleyes:

    DSCN8151 (1280x960).jpg DSCN8152 (1280x960).jpg
     
  16. Jun 23, 2018 #16

    Dave Baxter

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    Eric The one on my engine, and also on my sons 540 does not move that much maybe with worn engine mounts and multiple snap rolls it would, Wes should know? I would think that unless one was going to do unlimited acro, 3/4 of an inch should be enough? But then I do very limited acro. Dave
     
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  17. Jul 4, 2018 #17

    taff

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    Update on air intake
    I changed the aluminum tube for a 4".
    I used a Citabria flex coupling that I can join the servo side with the air entering side.
    A couple of photos to show the progress.

    DSCN8159 (1280x960).jpg DSCN8160 (1280x960).jpg DSCN8165 (1280x960).jpg DSCN8166 (1280x960).jpg DSCN8169 (1280x960).jpg DSCN8170 (1280x960).jpg
     
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  18. Jul 4, 2018 #18

    taff

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    All Parts Complete So Far

    Sending in a couple of photo's to show what I have so far.
    I think it's workable, in as much as getting enough air into the servo and having the front face as a push in after the nose bowl is in place. And importantly, not allowing air to enter into the lower engine bay plus allowing the flexibility of engine movement.

    I robbed the basic idea from the Citabria I had.
    Now I need to conjure up a filter and frame to complete my air intake.
    DSCN8179 (1280x960).jpg DSCN8182 (1280x960).jpg DSCN8183 (1280x960).jpg DSCN8185 (1280x960).jpg DSCN8188 (1280x960).jpg DSCN8191 (1280x959).jpg
     
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  19. Jul 6, 2018 #19

    taff

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    Air filter ?
    So I got a lot of good ideas during my intake design and now I am pondering over what air filter I should install.
    I see the one that mjk51 has constructed (photo copied and pasted below) and I like the simplicity of that.
    I could find stainless screening of two gauges like the example and sandwich them in a picture frame and secure it to the intake face.

    This should stop the big stuff like horse flies etc. but I am concerned about the small stuff like dust.
    Is there a thin sticky filter weave that can be cut down to size that could be suggested?
    front[1].JPG
     
  20. Jul 6, 2018 #20

    cwilliamrose

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    My S-2 has a Bracket air filter element cut down to fit in the available space. A support screen was added behind the element. I can get some photos since I have it apart now. The airplane was previously based in El Paso where dust is a big consideration. Not so much here....
     

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