FastEddieB wrote:3) Not sure about the recommendation to reduce power in the climb. It will necessitate a slightly higher AOA, which may slightly impede the flow of air into the cowling. In some planes full throttle results in an automatic enrichening of the mixture, which pulling back even slightly may defeat. Maybe there’s something quirky with the ROTAX whereby climbing at partial power may aid in cooling, but in general it’s not a good idea unless the manufacturer specifies it.
I agree. Here in steamy Georgia I have found in my CT that if the temps start getting toasty, reducing power does nothing at all to reduce the temps, and just increases the amount of time spent in the climb at those higher temps. Flattening the climb *does* have a good effect, and in the Summer I usually use a 90kt climb unless I'm trying to get to altitude in a hurry for some reason. If it's particularly hot I have even used 100kt climbs, or alternated between 90kt and 100kt on long climbs where the temps start coming up even at 90kt.
The good news on my airplane is that in hot weather the oil temps want to be 230°F or higher, but usually they don't want to get above 245°F unless I provoke them into it by climbing very aggressively. So it's pretty easy to get the temps to come down by shallowing the climb when the temps get over 240°F.
Altitude is your friend when it's hot. When flying long distances in hot weather, your temps will be much more moderate if you take the time to climb up high, even if it means a shallow climb. Planning your flights in early morning or late evening can help too, now that we have nice long summer days!