"Thomas Borchert" wrote in message
...

the engines run up to 6000 rpm, and are geared 3:1.

Not in cruise.

Even in cruise, the engine will run much higher rpms than your "usual"
engines. Your current engine will run 1200 rpm to spin the output shaft at
1200rpm, the new engine will be running 3600rpm to spin the shaft at
1200rpm. If you don't believe *Me*, ask someone competent to do the math
for you.


but more
problems seem folded back in with the liquid cooling.


........ Liquid cooling seems to be a total non-issue with the
Rotaxes, the new diesels and engines in general.

Liquid cooling does become an issue when you run out of coolant. A 2 gallon
reservoir is fine on a test stand with 3 techs standing around to keep an
eye on the run, but at night in the clouds or mountains, you will be
wondering how long it will take the engine to overheat and time to an
airport when a hose or gasket lets go.

Will an "engine in general" run for more than 30 minutes without coolant,
and would you bet your favorite coon dog's life on it?