Page 4 of 7 FirstFirst 1234567 LastLast
Results 31 to 40 of 64

Thread: Vernatherm

  1. #31
    Senior Member TroyBranch's Avatar
    Join Date
    May 2015
    Location
    Calgary Alberta Canada
    Posts
    273

    Default Re: Vernatherm

    I was out today. -21c. Oil cooler fully blocked off max oil was 164. To cold.

    On the first flight I had about 1-1/2" not blocked off, so 80% closed. A strange thing happened though. At the beginning of the flight oil temp starting rising nicely, got to 180 which surprised me, then all of a sudden the temp dropped quickly. Went right down to 154 before holding. Just like the vernatherm opened? Never saw that happen on any of my planes before.

    Remember, Dan is already blocked off 50% or so before he shuts it. No mention of the temps. Vernatherm is not holding temps like most assume. Dan , how hot is the oils getting for you fully closed?

    I since blocked off the top inlets on the cowling. I have no idea what they are even for. My thought is you have really cold air coming in there and hitting the top of the cooler, likely cooling the oil even more.

    Next mod is to get more air flow through the heat muffs. The heat really stinks at 0c. At -21c you might as well say it doesn't exist. . It is clearly an airflow issue. The air is hot, but it just dribbles out. I really think you would get way more pressure if the inlet was in the plenum.


    Sent from my iPhone using Tapatalk

  2. #32
    Senior Member Dan L's Avatar
    Join Date
    Jul 2010
    Location
    NW MT
    Posts
    568

    Default Re: Vernatherm

    I should have mentioned my actual temps. They were in the 150s and 160s. OAT was in the teens.

    Im not sure what it tells me. I remember that before I had a vernatherm at all I could see temps in the 130s in cold weather. At times I think I can see the vernatherm working. The temp might be steady at 165 and then drop about 10 degrees and soon climb back up where it was.

    Running the engine hard will push the temps up pretty quickly.
    Flying Carbon Cub EX #11 since 2011

  3. #33
    Senior Member Dan L's Avatar
    Join Date
    Jul 2010
    Location
    NW MT
    Posts
    568

    Default Re: Vernatherm

    I flew the EX with the shutter in place for about 5 hours the last few days in temperatures of about +10 to -5. And I experimented quite a bit with the shutter opened and closed at different power settings. I don't have an explanation for what I consistently observed and am putting this out here to see if anyone has an idea.

    Under these conditions I consistently saw a 10-15 degree temperature RISE with the shutter in the OPEN position. Closing it so almost no air would pass through the cooler would in less than a minute show a temperature drop. Opposite of what would seem to make sense.

    Any thoughts?

    image.jpg
    Flying Carbon Cub EX #11 since 2011

  4. #34
    Member DRL's Avatar
    Join Date
    Nov 2011
    Location
    Camarillo, CA
    Posts
    63

    Default Re: Vernatherm

    Just a guess, could the location of the temperature probe explain this phenomena? Or...when the shutter is closed, the vernatherm senses hotter oil, it then opens, increasing circulation and that gives a cooler indication. It seems your indications are a result of the interaction between the temperature probe, vernatherm and the shutter. You may have to take out the vernatherm to see what is actually happening.

    We have taped ours, but we are considering installing a vernatherm. The shutter may be better, so we are interested in how yours works. Husky's use a manual air blockage system and it seems to solve the problem.

  5. #35
    Senior Member ceslaw's Avatar
    Join Date
    Sep 2013
    Location
    Carterville, IL
    Posts
    384

    Default Re: Vernatherm

    I wonder if anyone has a diagram of the oil flow through the engine that would show the relationship between the oil cooler, vernatherm, thermostat, filter, pump, etc. That may also help solve the puzzle.

  6. #36
    Senior Member Dan L's Avatar
    Join Date
    Jul 2010
    Location
    NW MT
    Posts
    568

    Default Re: Vernatherm

    Quote Originally Posted by DRL View Post
    Just a guess, could the location of the temperature probe explain this phenomena? Or...when the shutter is closed, the vernatherm senses hotter oil, it then opens, increasing circulation and that gives a cooler indication. It seems your indications are a result of the interaction between the temperature probe, vernatherm and the shutter. You may have to take out the vernatherm to see what is actually happening.

    We have taped ours, but we are considering installing a vernatherm. The shutter may be better, so we are interested in how yours works. Husky's use a manual air blockage system and it seems to solve the problem.
    A good question. The only thing that would seem to change is the when the shutter is completely closed more cooling air will flow by the cylinders. That alone wouldn't seem to make an oil temperature difference.
    Flying Carbon Cub EX #11 since 2011

  7. #37
    Senior Member Dan L's Avatar
    Join Date
    Jul 2010
    Location
    NW MT
    Posts
    568

    Default Re: Vernatherm

    I was out loafing around today at low power settings 1600-1800 rpm and the outside temp was about 10. Opening and closing the shutter made no difference. The temperature stayed in the 155-160 range.

    IMG_1922.jpg

    A friend had called to tell me he'd seen a wolf on our place so that seemed like a good enough reason to go up for a look.
    Flying Carbon Cub EX #11 since 2011

  8. #38
    Senior Member TroyBranch's Avatar
    Join Date
    May 2015
    Location
    Calgary Alberta Canada
    Posts
    273

    Default Vernatherm

    I was out today to see what blocking the upper inlets would do. Rose the oil temp significantly as I expected. You want hot oil, block them too. I now have to take some tape of the oil cooler anything above -10c.




    Sent from my iPhone using Tapatalk

  9. #39
    Member
    Join Date
    Jan 2014
    Location
    Winchester TN
    Posts
    40

    Default Re: Vernatherm

    Troy.....your results seem to validate what you mentioned in post #31 regarding the upper inlets cooling the top of the oil cooler. What did you use to block the upper inlets?

  10. #40
    Senior Member TroyBranch's Avatar
    Join Date
    May 2015
    Location
    Calgary Alberta Canada
    Posts
    273

    Default Re: Vernatherm

    Quote Originally Posted by 3phase View Post
    Troy.....your results seem to validate what you mentioned in post #31 regarding the upper inlets cooling the top of the oil cooler. What did you use to block the upper inlets?
    Masking tape for now. If I build another one, I will order the cowling with these inlets not cut out.


    Sent from my iPhone using Tapatalk

Posting Permissions

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