Kitfox Aircraft Stick and Rudder Stein Air Grove Aircraft TCW Technologies Dynon Avionics AeroLED MGL Avionics Leading Edge Airfoils Desser EarthX Batteries Garmin G3X Touch
Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 29

Thread: Cooling air inlet duct opening.

  1. #11
    Senior Member
    Join Date
    Nov 2017
    Location
    Bailey, CO
    Posts
    225

    Default Re: Cooling air inlet duct opening.

    So, my duct has a bow downward, so the assembly didn’t want to fit under the upper surface. I did some trimming to accommodate the fittings as well as move it forward. I am just going to do some glass work to build a contoured surface that will fit over the top and keep the air going through the coolers. A picture is worth a thousand words. Thanks again.

  2. #12
    Senior Member efwd's Avatar
    Join Date
    Jun 2015
    Location
    Yorba Linda, CA
    Posts
    2,817

    Default Re: Cooling air inlet duct opening.

    Yeah, that is what I was talking about adding Cowl Baffel. As you can see, in mine, I have restricted flow over the top of the oil cooler and I probably have significantly reduced that one inch worth of radiator between the oil lines. Wonder if it will matter when the summer arrives? I enjoy the fiberglass stuff so it will entertain me to make the correction.
    Eddie Forward
    Flying
    SS7, 912iS, Garmin G3X

  3. #13
    Senior Member
    Join Date
    Nov 2017
    Location
    Bailey, CO
    Posts
    225

    Default Re: Cooling air inlet duct opening.

    I am reconsidering moving the oil cooler to a lower position. Does anyone know the specifications of the stainless steel used to make the brackets? I might try to source locally if I can find some.

    Steve

  4. #14
    Senior Member Cherrybark's Avatar
    Join Date
    Dec 2015
    Location
    Near Tyler, TX
    Posts
    509

    Default Re: Cooling air inlet duct opening.

    As usual, a search of the forum turned up the answer to the next stage of my build - mounting the radiator, oil cooler, and getting the ducting set correctly. This thread answered my questions and I really appreciate Eddie's pictures.
    Carl Strange
    Flying
    SS7, 912iS, Oratex, G3X

  5. #15
    Senior Member Flybyjim's Avatar
    Join Date
    Jul 2013
    Location
    Marysville, Pa.
    Posts
    585

    Default Re: Cooling air inlet duct opening.

    I am ready to set the duct flange in place in the lower cowl. How much space did you allow between the duct and the radiator? The instructions state "same spacing top and bottom" The photo in this thread looks like it is against but I'm wondering about vibration issues.

  6. #16
    Senior Member
    Join Date
    Dec 2017
    Location
    Mapleton,UT
    Posts
    1,224

    Default Re: Cooling air inlet duct opening.

    I had the same concern and I was assured the rotax don’t vibrate like the lycoming or continentals. I was advise to not set it too close making it hard to remove cowling. I ended up setting mine about 1/8” to 1/4” of space. I used a paint stick and set it onto of a paint stick for spacing.

    Last edited by Shadowrider; 01-19-2020 at 08:08 AM.
    Dustin Dickerson

    Building 7ss STI x 2
    Oratex
    29" shock monster
    EP912STI 155hp
    Garmin
    N33TF......FLYING!
    N53TF......FLYING!

  7. #17
    Senior Member HighWing's Avatar
    Join Date
    May 2009
    Location
    Goodyear, AZ
    Posts
    1,743

    Default Re: Cooling air inlet duct opening.

    Didnt catch whether this was mentioned or not. But in some research I did, I read that for maximum efficiency, the edges should be sharp - not rounded.
    Lowell Fitt
    Goodyear, AZ


    My You Tube Channel

  8. #18
    Senior Member efwd's Avatar
    Join Date
    Jun 2015
    Location
    Yorba Linda, CA
    Posts
    2,817

    Default Re: Cooling air inlet duct opening.

    I set the lower cowl at 1/8 inch from the bottom of the radiator. My NACA ducts you see in the previous post, are very close, if not touching and I don't find any kind of chaffing. It may have been me that recommended some additional clearance of the NACA to radiator simply because this is where I have some issue with lining up the lower cowl when installing. The clearances I have add challenges to getting to duct to slip up over the oil cooler. I have damaged the delicate cooling fins on the oil cooler. I don't have any cooling issues as I thought I might have. I use an 18 inch long (or about) segment of fire sleeve to block the air flow that was slipping around the radiators bottom edge. It helped cooling a bit. Enough so that it keeps my temps down under redline.
    Eddie Forward
    Flying
    SS7, 912iS, Garmin G3X

  9. #19
    Senior Member Cherrybark's Avatar
    Join Date
    Dec 2015
    Location
    Near Tyler, TX
    Posts
    509

    Default Re: Cooling air inlet duct opening.

    Those fins on the oil cooler are very delicate and a strip of firesleeve is a clever way to close the gap while protecting the fins. I assume the firesleeve is attached to the fiberglass cowling. How did you go about that?

    I've been a little concerned about long wait times for engine warmup without a thermostat. What have you been experiencing Eddie?
    Carl Strange
    Flying
    SS7, 912iS, Oratex, G3X

  10. #20

    Join Date
    May 2016
    Location
    Lindsay, TX
    Posts
    40

    Default Re: Cooling air inlet duct opening.

    Carl, my 912iS doesn’t have a thermostat, and it warms up quickly. I’ve flown on frosty mornings and it takes less than 10 minutes to get to operating temperature. In Texas I don’t think you have anything to worry about. Those living where it really gets cold may benefit from having the thermostat. My challenge was plugging all the drafty openings in the turtle deck.

    John

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •