Piper J3
Well Known Member
Let’s talk Oil Temperature in RV-12 with 912ULS….
I recently discovered a crack in the muffler and was able to find an exact replacement exhaust system with only 70TT. Exhaust system is identical to original that I just replaced and it’s in pristine condition. My 12 is an early SN with muffler located close behind the oil cooler.
Rotax originally allowed using Mobil 4T 10W40 Full Synthetic Oil. I continue to use this oil and now have 750TT with no problem.
With original exhaust I would sometimes see 240F oil temp in climb on a hot day. With new exhaust I see 250F oil temp at 85F OAT. Both CHT and EGT are relatively unchanged at ~ 200F and ~1290F.
I am in contact with Mobil Oil tech support and also Rotax with no definitive answers yet. They say they’ll get back to me in a couple of days, but could be like telling a child “later for sure”.
I’ve been searching the internet (I know… not good idea) and see automotive recommends 230-260F oil temps and I also see where Full Synthetic Oils can tolerate 300F.
250F is approx. mid-range yellow arc on Dynon D180 with Van’s preset limits for Oil Temp.
I observe that oil pressure does not fall off at the high oil temp.
My question… what are max oil temps observed in RV-12 with Rotax 912ULS?
Thank you in advance…..
I recently discovered a crack in the muffler and was able to find an exact replacement exhaust system with only 70TT. Exhaust system is identical to original that I just replaced and it’s in pristine condition. My 12 is an early SN with muffler located close behind the oil cooler.
Rotax originally allowed using Mobil 4T 10W40 Full Synthetic Oil. I continue to use this oil and now have 750TT with no problem.
With original exhaust I would sometimes see 240F oil temp in climb on a hot day. With new exhaust I see 250F oil temp at 85F OAT. Both CHT and EGT are relatively unchanged at ~ 200F and ~1290F.
I am in contact with Mobil Oil tech support and also Rotax with no definitive answers yet. They say they’ll get back to me in a couple of days, but could be like telling a child “later for sure”.
I’ve been searching the internet (I know… not good idea) and see automotive recommends 230-260F oil temps and I also see where Full Synthetic Oils can tolerate 300F.
250F is approx. mid-range yellow arc on Dynon D180 with Van’s preset limits for Oil Temp.
I observe that oil pressure does not fall off at the high oil temp.
My question… what are max oil temps observed in RV-12 with Rotax 912ULS?
Thank you in advance…..