The Orenda would be a lot more than just a major cooling project.  From the
web site:

Dry Weight with Accessories: 750 lbs

I recall talking to a guy who was part of the early program that hung the
pre-Orenda version on a Turbine Twin Commander.  By the time the dust
settled, with everything included, wet, ready to go, the weight in front of
the firewall was approaching 1200 pounds if memory serves correctly.  The
additional weight was ALWAYS more than the turbine fuel weight saved no
matter how long the leg.   The turbo alone looked large enough for a small
locomotive.

Think replacement for big old radial engines on crop dusters that need 600
HP to haul all that payload off the runway.  

Don't think Lancair.  

But what do I know?

Fred Moreno