I fink (emphasis on THINK - I could be wrong) the engine in the Mirage is a TIO-541..... thats the 'tuned induction' version of the TIO-540 (also found in the Duke). Its problems (apparently after research into all the various failures) stemmed mainly from a lack of understanding of how to run the engine using the recommended 'Peak TIT" and 'Lean of Peak' method - for which the engine was optimised and instrumented.
The basic design of the -540 is rock solid - although it has been let down by some poor parts quality in the not-so-distant past. I've said before that anyone running an aero engine without all-cylinder monitoring and trend capture is taking a major risk; literally betting everything on uncalibrated and isolated readings from antique dial guages. My rude awakening on this came after fitting a JPI to my Aztec (IO-540s) and comparing the standard gauges to the all-cylinder readings. This bolt from the blue was rapidly followed by a set of GAMIjectors. If you haven't seen this gear in action, find someone with a setup and check it out. It WILL change the way you fly and manage your expensive engines - as well as save major $$ in fuel and maintenance. I would LOVE to see data capture from the failed PA31 engine in this thread, and how long before the failure (whether) the engine was indicating a problem........or in the Whyalla Chieftain....
Oh, BTW Torres, the V-6 driving the Commodore (todays FJ) is a Buick design that dates back about 1960-something......
