On a massive great '40s radial hanging out in the breeze, I reckon it would be a problem, I'm talking about on (slightly!) more modern enclosed lycomings and continentals as fitted to the majority of light a/c. These don't operate anywhere near the power levels of the big radials and the engine handling characteristics are very different I assume, also they usually operate at much lower speeds, so the cooling effect would be much less.
I wonder whether the idea of 'shock' cooling comes from the days of the radials where it was a problem, but like many aviation myths continues to this day.