I am in a excellent position where I have access to aviation engineers who perform component failure analysis, metallurgical etc. I have provided several photos of the failed cylinder heads from this thread to a metallurgical engineering friend of mine at one of two firms that I deal with. My engineering friend is very interested in doing a component failure analysis on FG-60 failed heads. Unfortunately I do not have a failed cylinder head to send to my friend for him to do the failure analysis.
I suspect any owner of an FG-60 R3 that has had a cylinder head failure has sent the FG-60 back to HH for warranty repair? Unfortunately, I am a long way from being able to run and flight test my FG-60 R3.