Detonation happens, but when you do it with a power adder, the end result can be carnage. In this particular case, the damage was minimal and it wasn't caused by the power adder itself, but more from an uneven fuel distribution problem. Once it got hot, metal transfer took over and the spark plug electrode got embedded in the valve, causing us to lose cylinder pressure. No biggie, it just gives us another opportunity to detail a valve job.