I'll just say you need to do a little more research (and not just on English) before you post. Most of what you have said is wrong, or in modern parlance, "alternative facts".

On Wednesday, September 16, 2020 at 1:15:05 PM UTC-7, Dave Walsh wrote:
At 19:27 16 September 2020, Eric Greenwell wrote:
Dave Walsh wrote on 9/16/2020 9:06 AM:
I can't think of anything polite to say about Wankel engines... a
vibration free engineers nightmare?

How is "vibration free" an "engineers nightmare"? It's certainly a
pilots
dream!
After 200 engine hours spread over 25 years, I have not had a
significant
vibration induced problem! Try achieving that with a two stroke.

Here's some actual comparisons: a while ago, I searched the postings
on the
Wankel
powered Schleicher glider group for key words like "vibration", and
also on
the
DG/Solo group. There were few to found for the Wankel engine, and
they were
a
small minority of the issues discussed. The search of the DG/Solo
group
found a
LOT "vibration" issues, and they were the big majority problems.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email
me)
My poor use of English, perhaps I should have said the Wankel is an
engineering nightmare (without vibration problems)? Clearly some
pilots have reliable Wankel engines; others are not so fortunate. Luckily
we're in a democracy so we can choose which (unreliable) engine to
buy. Current DG models have Solo not Rotax engines. I don't like any of
them. There are some nice Japanese two strokes out there, just not in
any sailplane. Despite the reported lack of vibration the bolts holding
some Wankel engines together seem to have a habit of falling out?
Assuming all motor-gliders are unreliable seems a safe bet.