fbpx

 

Hi everyone,

I am doing an installation of a 912UL, and I look that the oil temperature sender, which is right after the pump, which is right after the oil cooler (in the sequence of fluid flow).
Of course, the oil that comes in has just been cooled by the oil cooler, so its temperature will be representative of the effectiveness of my cooling installation.

But I would also like to know what is going on inside the engine, by monitoring the temperature of the oil EXITING the engine, going back to the reservoir. Putting a sensor on that line would give me a temperature reading of the INSIDE of the crankcase, which I find as important. Especially knowing how hot the oil gets in that engine!

I've done a search on this subject, without results.
So I would like to have your opinion on this subject. Would it be worth it? Has anybody tried it already?
I understand that an inline adapter would be necessary to be able to install a sensor. Or it could be integrated in the outlet fitting underneath the engine.

Thanks
  • Re: Why don't we monitor crankcase temperature?

    by » 6 years ago


    This was changed on the 912iS engine on where the oil temp is measured.
    For your purposes and since 1990 it hasn't been an issue and I wouldn't worry about it. It's that way for most of the 912's out there.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell


  • Re: Why don't we monitor crankcase temperature?

    by » 6 years ago


    OK thanks for the reply.
    But just for the heck of it, while I'm redoing everything, I think I'll make myself a dual-sensored switchable oil temp gauge setup! ;-)

  • Re: Why don't we monitor crankcase temperature?

    by » 6 years ago


    This was changed on the 912iS engine on where the oil temp is measured ...


    Yes! the 912is sensor is at the rear of the crankcase and measures the oil while still hot.
    If you insist on measuring the oil at its hottest, remember that the bottom of the block has multiple oil return ports.
    You are only using one of them.
    It would be easy to adapt a temperature sensor to fit into an unused port.
    It would be bathed in the Hot Oil as it is being scavenged from the bottom of the "Oil Pan".

    Bill Hertzel
    Rotax 912is
    North Ridgeville, OH, USA
    Clicking the "Thank You" is Always Appreciated by Everyone.


  • Re: Why don't we monitor crankcase temperature?

    by » 6 years ago


    I have done this with another engine...
    a good thing to do if you are an engine developer. However once the system is working you find that the difference between the IN and OUT oil is only 1-2 degrees. Similarily with water temp we measured the temps a 6 points including into and out of the radiator and the difference is only a couple of degrees. Naturally this is counter intuitive, but generally the reason is that you get benefits by over sizing the pumps, oil and water. Oil pump needs oversizing to produce the pressure you need hence the flow is high. Water, the race guys figured out years ago that over-sizing solves hot spots cavitation and microbubble problems. I cannot remember the oil flow numbers but for water it was 120L /minute therefore we had a complete cycle ...ie all the water flowed from the radiator through the engine and back again in less than 3 seconds, so practically the temp was the same everywhere..illogical as it seems

    Therefore for a production engine like a Rotax it is not needed and unlikely to give you a result anyway

    Thank you said by: Ken Ryan

  • Re: Why don't we monitor crankcase temperature?

    by » 6 years ago


    Thanks Glenn. Very interesting. Counterintuitive until one thinks about it!

You do not have permissions to reply to this topic.