On 2005-03-23 08:44:32 -0500, (Max Kallio) said:

I'm really interested in these new ZOCHE aero-diesels www.zoche.de.
They are air cooled, piston ported, radial configuration, turbo- and
supercharged, high pressure direct injection 2-stroke diesels. The
70hp weighs 55kg (121lbs) and uses 10.1L (2.68gal) per hour @75%. The
TBO is expected to be 2000hr and guite cheap too. Low parts count and
slow revs.


The Zoche diesel has been coming to the experimental shows and tempting
dreamers for, I believe, around twenty years. He has yet to ship a
single motor to a customer, but he's put the touch on the state of
Bavaria, among others, for venture capital.

To put it another way, Thielert started about fifteen years after this
guy and has diesel engines certified and in production in flying
aircraft. SMA also, but they don't have a launch customer. In their
case it is due to normal teething on the motor -- and they are a very
well-resourced outfit.

Take a look at Zoche's FAQ and specs and you will see that "specs" in
this case stands for "speculations." An engine that hasn't been built
and hasn't been tested and that still is in relatively early stages of
design.

My personal advice is: if you are going to be doing an experimental
helicopter, you should do like old Igor did on the VS-300 and buy a
motor from someone that has been selling aircraft motors for a while,
and actually delivering them. I've seen a lot of experimental projects
come a cropper because someone was on an unscientific quest to
revolutionise both airframe and powerplant.

For instance, the only auto engines that seem to have adapted well to
aircraft use, despite the theoretical benefits of some of the Honda
motors or the various Wankels from mazda, are the ones that

Max, and all, you gotta pick a hill to die on. Some fights are not
worth fiighting. If your interest is in powerplant development for
rotorcraft, acquire a fully-sorted and proven-maintainable airframe,
and reregister it in the Experimental R&D category, and go to town with
your motor. And I would pick something with very benign autorotation
characteristics is I were doing motors R&D, just as a simple matter of
risk abatement. I.e. a Schewizer might serve you better than a Robbie
for that purpose, even though the R22 might otherwise be ideal.

It's essential scientific method to monkey with only one variable at a time!

cheers

-=K=-

Rule #1: Don't hit anything big.