People often say the Rotax 912 seems to cool TOO well at times. Of course that is better than the reverse.
With that in mind, my plane isn't yet flying and I'm just running the engine each weekend to keep things dry and oiled up.
Because there's not much load, and the weather is getting a smidge cooler it's not easy to get it warm enough. My engine has two oil coolers, the same size and one radiator. Last week I taped one oil cooler up, and it didn't make a difference. Today I went further. I taped up BOTH coolers and half the radiator. It finally went from just under 90° to nearly 95° 😄
Obviously, in reality I haven't blocked 100% of the oil cooling because there will be air turbulating behind each cooler, taking some heat away. And needless to say, I fully understand if there was a proper load (taking off) I would soon know about it with all that taped off 😂
Still amusing though. It will stay taped off for now, so I don't have to run it for 30 minutes trying to warm it up.