On Tue, 26 Jul 2005 23:58:12 -0400, "Gordon Arnaut"
wrote:

However the wankel engine has some incredible advantages, including
smoothness simplicity, ruggedness and power potential that truly puts it a
class above the piston engine. There is no question about that, as
rotary-powered race cars have proven over and over -- until they are banned
because they simply have an unfair advantage.

Regards,

Gordon.

It's true that the rotory offers some interesting advantages, one of
which is the ability to continue to run and produce power after the
engine has lost compression due to overheating and warped side seals.

It will make power right to point where you shut it down, but you
won't get it started again because of low compression.

I guessing that it's disadvantages were enough that it never appealed
to big auto makers to work on them. Wankel itself was unable to make
it a success and it's hard to argue that Mazda has either. It's fuel
consumption and inherently dirty emissions which require a lot of
technology to clean up plus the investment in machine tools to create
it just didn't seem worth it to the bean counters, I suppose.

And the public did not seem to care much that it was available. When
Mazda first brought it out, it had a number of quirks that the buying
public had trouble getting used to. It had a cold temperature
starting assist that consisted of an injector that added pure
antifreeze from a seperate tank into the intake manifold. This of
course created a dense white cloud of smoke, which the owner was told
was normal, and it was, but it sure made owners nervous to see it.
And the owner had to refill the tank, which they often did not do,
which resulted in hard cold weather starting. Add this to the manual
choke, which the RX-7's had for many years and which the public had
difficulty using and it's easy to see why it was popular only for a
limited number of people.

Then there was the stench of the exhaust. Nothing smelled worse, not
even a diesel, and you could not tune it away. When properly adjusted
for emissions, it stank most powerfully, it felt like it was actually
burning your nostrils.

Mechanics didn't like it because it had two ignitions called a leading
and trailing ignition and originally, the distributer held three sets
of points in two layers. Not easy to adjust and naturally
problematic.

That of course went away with the advent of electronic ignition, and
eventually the engine was fuel injected and everything was computer
controlled. But converting such an engine for use in an airplane is
not without it's challenges.

Corky Scott