Warm Up Times of Radial Engines.

lol - ok, guys. NOTE: I was there BUT did not shoot this video.

It was the end of May in Atlanta. Was comfortably warm, not hot by any stretch, and slightly humid. It was the first start of the day for the Jug. The video is clipped but it was not a twenty or more minute delay to takeoff, more like fifteen. The taxi was nearly half of that with run-up the majority of the other half. Even with the paddle blades there isn't an awful lot of airflow from the prop on the ground so the danger is almost always (unless in the snow, of course - lol) overheating before takeoff. Heavy bombers at large bases lining up for massive raids would sometimes adopt the technique of taxiing on inboards, then switching to outboards and then back again to control temps (and that's with paddles). The bat handles on the early F4U, as a contrast, required rather quick, deliberate action on the ground in the Pacific, as you might imagine.


... AND ... once you're good for 1000+ rpm (40C) you're good to go, temp wise. What might hold you back a little is if you are paying for it (you just can't baby your $75000 motor too much, eh?). The taxpayer was swapping out the engine in a couple hundred hours (at least, hopefully) during the war so they did what they did back then (i.e. use 70" for takeoff). Ground crew run-ups prior to missions were as much or more a systems check as engine warm-up.