I'm interested in installing a diesel in our Legacy.
Since we put down the deposit on our kit at Oshkosh, I was able to
look at the display of that TCM/NASA/GAP engine:
  http://www.grc.nasa.gov/WWW/AST/GAP/
and ask questions of the Lancair folk -- including Lance -- before
taking the plunge.  The prospect of having a diesel option certainly
didn't hurt.

Information on the GAP engine was pretty much pie-in-the-sky, but
still encouraging.  No definitive answers to questions like:
  When will it be available?
  How much will it cost?
  How much horsepower will it develop?
  What about problems starting?
  What happens if the turbocharge fails?

The Lancair folks assured me that the Legacy should handle Jet-A
with no problems.  (I'd been worried about fuel tank sealants and
plumbing.)  My recollection is a bit vague, but I do remember that
Lance smiled and said that they were involved in the GAP project and
that a Lancair (Legacy?) would likely be one of the testbed aircraft.

Even though I'm brave/stupid enough to think about putting a second
throttle in our Legacy, I'm much less eager to pioneer any engine/
propeller combination that Lancair hasn't blessed.

That said, I've been hoping that we'd have a diesel option by the time
the Legacy is ready.  I even tried to delay the ship of our engine
mount, but Lancair wanted a commitment.  Didn't seem reasonable to
hold them up indefinitely so we opted for the 550.  But I'd still
probably spring for a new engine mount and cowl if I could bolt on a
diesel -- assuming it isn't too dear and that I could expect longer
TBO, cheaper operating costs, as good or better range, no "lead"
worries and performance that's even close to the IO-550.

-------------------
Paul Davis
Lancair Legacy builder
pdavis@bmc.com
Phone 713-918-1550
-------------------
Omnia iam fient fieri quae posse negabam
Everything which I said could not happen will happen now