On Nov 21, 9:55*am, Morris Dovey wrote:
J. Clarke wrote:
B A R R Y wrote:
Robatoy wrote:
Btw, I have been reading a bit on diesel aircraft engines. They
seem
to have quite a following.
They had great promise, but Thielert, the biggest player, who based
theirs on a Mercedes turbo diesel, went BK. *According to a podcast
I
listened to a few weeks back, Thielert left far more orphans than I
would have guessed.

Since jet fuel is far more available worldwide than avgas, I thought
it was going to be big! *I think the main reason for the lack of
interest in North America was the easy availability of avgas, and
the
availability of a relatively easy 87 octane auto gas conversion for
many engines. *Lots of guys who did the 87 conversion are now having
problems finding ethanol-free unleaded...

I suspect that ultimately a multifuel engine would be a more fruitful
approach, and small multifuel reciprocating engines do exist--the Army
used them on trucks a while back and Evinrude has a multifuel
two-cycle outboard. *Don't know how the Army does it but Evinrude uses
direct injection like a diesel but with relatively low compression (by
diesel standards) and a spark plug.

Hmm - In my ignorance, I have to wonder how well a low compression
engine would fare at 8000'/2400m. Would that work?

That would be extra work... dragging that lumber up a mountain like
that?
What if you didn't have a mountain nearby?