"Given the available data, it strongly suggests "shock cooling" is nothing but a myth, at least in the context as commonly explained.
Kas Thomas, a respected aviation engine expert and author believes, "shock-cooling is not a major contributor to cylinder head cracking".
Since many people do not run their engines correctly (eg. they run at CHTs that are way too hot), shock cooling can become a problem if, for example, you run at 460 CHT and go full rich and bring the throttle to idle. If you run your engine sensibly, though, it's never an issue.
All the other explanations fall down when you ask why cylinders don't crack due to shock heating, on takeoff.
Or why the cylinders don't self-destruct when you fly into rain.
Nonetheless, the topic will remain highly controversial and surely continue to be hotly debated well into the future".
For me in a LongEZ with a O-320 it's a non issue. I also don't need another light flashing or warning with a voice telling something I should already be aware of. If you believe shock cooling is a problem then you should know how to control or prevent it just like you've done before Dynon came on the market.
Lots of info on Shock cooling on Google
1. http://en.wikipedia.org/wiki/Shock_cooling
2. http://www.avweb.com/news/maint/182883-1.html?redirected=1