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Brand new Rotax 912ULS (7 hrs).

Dynon Sky View - records engine parameters.

In flight (hot engine/oil/coolant)  - We seem to have unexplained high pressure peaks (not fluctuations), followed by equally rapid reductions in pressure,  that may be associated with reduced power and rapidly rising oil  temperatures.

The peaks may rise to 70 psi - there is a sort of normal level around 55 psi

Any suggestions as to what might be the cause/remedy ???

  • Re: Oil Pressure Peaks

    by » 2 years ago


    Sounds more like a connection issue and not a real pressure issue.


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


    Thank you said by: Sean Griffin

  • Re: Oil Pressure Peaks

    by » 2 years ago


    Roger Lee wrote:

    Sounds more like a connection issue and not a real pressure issue.

    Please expand Roger.

    I would have thought that an intermittent restriction would have been most likely when moving from lower to higher RPM eg take-off .

    I am using Rotax supplied (Continental) oil hose with attention to minimum bend radius. I have one short length, oil cooler to pump, where the hose bends 90 degrees - have been contemplating fitting an external spring, just in case it is collapsing. 

    Otherwise the only other possibility, that comes to my mind, would be a sticking pressure relief valve - what would be the symptoms? and given this is a new engine, might I expect this to improve with use/ware?


  • Re: Oil Pressure Peaks

    by » 2 years ago


    Ah! "The penny has dropped" - Roger, you think an electrical connection.  BUT what of the rapid rise in oil temperature, at about the same time?


  • Re: Oil Pressure Peaks

    by » 2 years ago


    Real temps and pressure usually do not change at the snap of the fingers. It takes a few minutes to rise and sometimes longer to go down. The fact that it's brand new also has me looking towards an electrical issue vs a real one. It could be at the instrument, it could need a resistor inline, could be a poor ground, ect... 

    It's the fast up and down that says to me it isn't a real temp / pressure issue. New engine not likely a real problem. more like the installation of the wiring or instrument.


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


    Thank you said by: Sean Griffin

  • Re: Oil Pressure Peaks

    by » 2 years ago


    If you aren't already using this, check out https://www.savvyaviation.com/savvyanalysis/  You can create a free account, then upload your data logs for a nice graphical representation, which is VERY helpful.  If what you're seeing is more of a spike, and not a gradual change, I'd agree that it's more likely a measurement error of some sort.  

    Rusty


    Thank you said by: Sean Griffin

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