Posted for "FredE" <fwegli@astound.net>:

 Those of you who are looking at using the TSIO-550 engine in the ES must be
 aware that the IV cowling, intended for the TSIO engine not only has the
 "Dolly Parton" exhaust bumps, but also has a one inch larger dia. intake
 openings for the additional cooling required  for the higher power operation
 capability at altitude. I used the ES cowling on my normally aspirated
 Lancair IV and it works very well - more than enough cooling - but if you
 use the TSIO engine, you should use the IV cowling designed for the TSIO-550
 engine. My $0.02 worth.
Fred Egli LIV N1228E > 500hours and love it.