Hi Paul-

Just wanted to share a very earnest conversation I had today.

One of the visitors we got while running the engine was an alleged
former rotary-powered airplane owner.  He was terribly interested in
telling us that "Apex seals are completely optional for aviation use.
They're only needed by cars so they can idle; for aviation use they are
not needed."

Wow...

Mark (Rocky Mtn High)


Yes I have heard rumors to that affect. If you can spin it fast
enough to start it will run at high RPM with no apex
seals. The question is: Is that practical? :)

Paul Lamar

Impressive.

What sort of gap losses would such an engine suffer? At what RPM would
that actually be efficient (ie achieves geometric/theoretical
compression and expansion ratio)?

I wonder if an apex seal failure would then not put an aircraft engine
out of commission -- or would the damage done to the rotor or housing
guarantee loss of seal...

-Chris

I don't know the answers. It is just a myth I think.

Paul Lamar