Oil temp threshhold for engine breakage? (Mainly Merlin engines)

[Igo kyu]

Did they know about the counterflow multiplier in WW2?

http://en.wikipedia.org/wiki/Countercurrent_exchange

It makes a huge difference to efficiency.

In a 1951 lecture along with his student V.B. Hargitay, he was the first to hypothesize the countercurrent multiplier mechanism in the mammalian kidney, later to be discovered in many other similar biological systems.

http://en.wikipedia.org/wiki/Werner_Kuhn

So, perhaps not?