Originally Posted by
megan
One of the major problems with the B-29 during WWII was overheating during the taxi for take off, such that there was a CHT limit laid down for commencing the take off run, reach that and it was back to dispersal, take off was commenced with the cooling flaps fully open and the flight engineer with an eye on the CHT's progressively closed them while barreling down the runway. They learnt that maintenance of the cooling baffles around the cylinders was critical. Certainly could take battle damage though, reports of radials making it home with cylinders missing, as in shot off, not misfiring.
The big problem with the B-29 engine was that it was a four-row radial (I believe the first ever attempt at a four-row radial) and cooling the back row was very problematic - especially as you note when there wasn't a lot of airflow through the engine.
Having race air-cooled engines, one trick to keep air-cooled engines from overheating was to run them intentionally fuel rich - the extra fuel that can't burn acts to keep the peak temps down (rather counter-intuitive to run more fuel to cool the engine but it works). Of course that has an adverse effect on range...