I'm curious about your statement as I have the same setup but have not run it yet. You say you smoked the piston. Does it have a hole in the middle? If so does it look melted? Is inside of the head discolored or mottled? Is the rest of the engine ok? I ask this because these are indications of pipe problems not engine overrev. There was an article in RCJI a couple years ago about the time I was having problems with my Dynamax/Webra 80. My problem was the pipe. I saw some of the early indications of what they were describing in my engine. Changed the pipe and it ran fine till the rod let go
Thanks for the input on this fan/engine combo!