We recently decreased prop pitch on our 912 ULS from WOT 4800 rpm to 5200 rpm. Runs fine, but oil temp is running significantly hotter. Previously averaged 160-185 even with prolonged climb. Now ranges about 20 degrees hotter and does not tolerate as steep a prolonged climb angle before reaching Yelllow on the Oil Temp gauge. Once in level flight it cools down, and lower ambient air temp of course moderates the effect. Is it most likely the change of prop pitch and the increased engine rpm that has caused the change?  Thanks

Dave G.

  • Re: Oil Temp and prop pitch relationship

    by » 3 months ago

    Is 5200 wide open throttle (WOT) all you can get in flat and level flight? If it is you're severly over pitched and over pitching for anything under 5500 WOT will increase oil temps. That said in the hotter summer months there is nothing wrong with going into the yellow arc area for take off climb. That is actually pretty normal. Yellow just means keep an eye on  me so I don't go into the red. Seeing 230F - 245F in climb out is normal and okay, but once in level flight the temps should drop back down to around 215F - 225F. The oil temp most times are tied to prop pitch, but the big factor is engine and cowl setup that controls air flow over the engine and through the coolers. Some aircraft are just setup better to allow more air cooling.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-574-1080 Home (TRY HOME FIRST)
    520-349-7056 Cell

    Thank you said by: RotaxOwner Admin

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