fbpx

 

I have an AirCam (twin engines mounted on top of wings with no cowling)
I have thermostats and they show they are functioning well (readings right after a flight on the oil cooler show that the thermostat is by passing the cooling coils as it should since the temps are low)

Both engines show the same oil temp and only reach 120F after a lengthy taxi and warm up.
They don't get to 160F until 20 or more minutes into a flight and never exceed 165F

Is it possible that because the engines are so exposed (average temp has been 60F OAT) the oil temp is not going to reach a higher temp? I have a new temp sensor to try replacing one of them to see if that makes a difference. I was told not to put any sealant on the threads to ensure a better ground. Please advise.
  • Re: low oil temp readings

    by » 8 years ago


    You can try the new sensor, but if both are reading the same i doubt that
    s it. Try putting a piece of 2" aluminum tape across the oil cooler and radiator. This will help with the temps. Your exposed engines will take more to get them hot. You have total engine metal exposure giving up all that heat and is exposed to all the outside air.

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


    Thank you said by: Jonathan Marbach

  • Re: low oil temp readings

    by » 8 years ago


    I had heard of that approach, but the thermostats are doing their job and bypassing the radiators.
    I agree that its not likely the sensors or the reading would be different. The reading is taking place just before the oil pump and this has got to be the "coolest" point in the system. I would imagine the oil temp inside the engine is much warmer, right?

  • Re: low oil temp readings

    by » 8 years ago


    That's true, but if the real reading is 120F that's too low. If the thermostats are doing their job why is the temp only 120? The thermostat is set for at l set at 180 and some higher

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


  • Re: low oil temp readings

    by » 8 years ago


    The oil thermostat does not completely shut off oil flow to the oil cooler radiators. There is approximately 10% flow through the oil thermostat and oil cooler when the thermostat is "bypassing" the oil cooler.

    In colder temps you requires the aluminum tape to keep temps up.

    My first flight in winter 5F OAT with the oil thermostat a few years ago, produced only 140F oil temp, two strips of aluminum tape on the oil cooler brought oil temps to 215 F. This is with a cowled engine.

    Thank you said by: Roger Swanson

  • Re: low oil temp readings

    by » 8 years ago


    We may all be over-discounting the effect of the Oil tank.
    It accounts for over a square foot of cooling surface subjected directly to an 80 mile an hour wind.

    The oil temp should not be measured as it enters the engine.
    It should be measured at the oil pan as it exits the engine.
    You want to measure it at its highest point, not the lowest.

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


You do not have permissions to reply to this topic.