Vance and Emily Jaqua wrote:

Paul- re phrasing my statement - I feel that the
Wankel is less of a true "rotory" engine than the
spinning rotories of WW I . These engines required
essentially no balance weights since all elements
were travelling in almost a true circle, there were
no orbiting nor nutating elements as there are
in the Wankel.

I disagree.

The rods in a WW I rotary radial rocked back and forth as
the engine rotated. If that were not the case there
would have been no need for big end rod bearings.

Close examination of this picture from
A History of Aircraft Piston Engines by Herschel 
Smith will prove that statement. ww1rot.jpg

In a Wankel engine there is nothing that does not move in
a circle. The balance weights are there to take
out the couple caused by multiple rotors being displaced
in the fore and aft plane. As such it is entirely in
complete balance.

Every mechanism that has been used as a pump has
 been tried as an engine, mostly with very limited
 success.
Do you consider the spinning cylinder bent elbow
engine touted by Smokey Yunick a rotory?

Never heard of it but there are hundreads of thousands 
of low cost Mazda rotary engines out there waiting
to be converted to aircraft engines. :-)

As you say, displacement is meaningless unless you
are trying to set class rules, and has always been
an item for vigorous disagreement on Wankels. If you
look at the trochoid, you could say it is a large
 engine running slowly, from the output shaft, a
small engine at high rpm. The bottom line is that
it pumps a lot of [air] mass, making power from a very
compact unit with low frontal area, and deserves
more general success than it has achieved.
Keep em flying ! Vance

Paul Lamar
 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org