So what was your reason for asking Aircon?? I hope you're not going to come in and see me with a "since you serviced my car....." complaint....! Love this internet spying game! The most likely thing to let go on a buzz is the valve train on a simple engine with only 2 large valves per cylinder, but with moden trends using multi (lightweight) valves, the springs now do less and less work. Valve float on multivalve Ferrari's is, I think, extinct. I recently did the second refresh on a 360 Challenge engine, which had had the inner spring missed out of one of the exhaust valves at the first refresh....with no ill effects after 5000km of hard racing and limiter abuse (Aussie celebrity Sam Newman). With the titanium conrods now used, the metallurgist always seem very vague as to how to life them. I simply crack test them at the first refresh, and if ok I'll replace them next time... I've seen two 360 engines that have had the small end of the rod open up at it's highest point. The N-GT car has lighter pistons, but rev's higher so loads are similar. The piston speeds are astronomical and the titanium simply cannot cope beyond a "still to be ascertained" limit. When the small end breaks...the remains of the rod are still connected to the crank and turn into a "helicopter axe" to the rest of the block...... By the way, the Porsche Carrera cup out here is in a right pickle, with up to 15 clutches popping every meeting due to over revving or missed shifts. The springs in the pressure plates simply collapse and distort, causing huge vibrations at best, or complete failure at worst.