f3a05
Anything above 60C is basically too hot to touch, and at 30+C it would be normal to be above that, so checking by feel is not a very good way to determine temperature. In all my time I have never felt the need to allow a motor to cool off before the next flight. Simply, the hottest point your motor will get is shortly after landing, the moment you takeoff for another flight it will cool off from that point and begin operating at normal temps. As long as your motor is not exceeding about 80C after landing measured on the outside can, then you are OK.
I have many times flown back to back in temperatures at 35C+ while at the US Nats in Indiana, where it is very hot and humid without problems.
ORIGINAL: f3a05
We’ve had relatively high ambient temps here recently(30degrees C).
I don’t have an accurate measure available, but my Plettenberg motor was landing too hot to touch, and taking 30 minutes to cool sufficiently for me to feel happy about flying again.
This “spinner with the nose cut off”,with a skeleton aluminium back plate, allows me to have just a ten minute interval between flights.
Crude, but effective, apparently.