Get the most out of the bf109

[Cap'n Crunch]

Don't have the game yet, but as far as your water rads, most will regulate the flow of water both ways. If it's cooling to effectively, a thermostat on the rad exit flow will close stopping the cooler water from flowing to cold back into the engine block. Most are familiar with the hot thermostat controlling flow to the rads, the autos have these, it's all they need. They don't operate in such extreme temperature bands with rapid changes.

Your oil system should be modeled similar, two control points. In real life, oil rads are often locked full opened a little prior to descents, if your going from cooler altitudes to extreme heat at low levels. It can buy you several extra minutes of ground engine run time dropping oil temps a few degrees and cold soaking the rads, handy for a quick combat turn around or an engine running offload.

Might be a better idea to open the rads full in a dive and slap them shut in the zoom. If your taking long dives and max effort zooming for it might pay off.