BTW Mario from Wankel Ag called me from Germany and he is
setting up a
subsidiary in Oregon. We may see some oil cooled rotor all
aluminum
2 rotor 100 HP engines in the near future.

He has received some venture capital and is buying Hass NC
tools as we
speak
for his factory in Germany.

Paul Lamar

That is some wonderful news!

I was about to ask Marioa about this, but this clears the
situation.
There's indeed a gap here, between 13B derivatives and
45Hp 1-rotors.

Cheers,
Petri

I am thinking of going to Germany a few days before Aero
and visit
Mario's new factory so I will upload a report and some
more pictures
then. Mario will be selling my book at Aero.

Paul Lamar

Paul & Group -
an excellent opportunity to build in turbo compound power
recovery at the
design stage , maybe with an axial - flow turbine.

--
Bryan In England

Yes and no. From a business point of view when capital is
in short
supply and risk is high it would not be the right thing to
do.

Paul Lamar


Paul, If it is not a propriatory issue for them, could you
find out what
they will be using for the wear surface on the side
housings and the rotor
housings.

george grimes

I'll try. It has been electrodeposited lipophilic nickel
matrix silicon
carbide coating AKA Nikasil in the past by Wankel Gmbh.
The really good
Nikasil supplier in Europe namely Maule has refused to do
it
on aircraft engines. Wankel went elsewhere and had
problems.

The real trouble with coatings is there appears to be no
way of non destructive inspection or testing.

The only way is to take a lot of samples and test them to
destruction. That is what Mazda did ands det gun won.

One of the problems with Nikasil is it works well
on cylinders but not so good on complex shapes like
trochoids
and flat surfaces.

http://kustom-kraft.com/NEWNIKASIL.html


"How do you know when your cylinder needs be re-Nikasiled?
Some times its not that easy to tell, but usually you can
tell by looking at the cylinder walls. If you can see
scratches or chips that's a sure indication that it's time
to have your cylinder re-plated. If you can't see any wear
or damage that doesn't necessarily mean your cylinder is
in
good condition. The inside of the cylinder has to be
exactly round (to with-in specs) to perform properly. This
can only be accurately checked with a dial bore gauge."

"They can measure to with-in one ten thousandths of an
inch.
The Nikasil plating that's on the walls of your cylinder
is
only a few thousandths of an inch thick but is very hard.
It wears extremely well as long as everything is tight and
sanitary. If you maintain your engine as the factory
recommends it will last for years. However we all know how
easy it is to suck it full of water or dirt or maybe run
it
low on oil or some other mistake you'll be needing our
service. The Nikasil plating, or coating as its sometimes
refereed to, will have to be stripped and re-plated."



Paul Lamar


Paul, I do have a dial bore guage for measuring cylinder bore and out of
round checks and could mill a pair of spacers to put between 2 side
housings to check a rotary. By using different combinations of side
housings I could determine which ones were out of tolerance. I also have
a long bar micrometer depth guage that would give accurate testing.

My objection is to any coating where the inspection criteria lists CHIPS. A
chip of hardsurfacing could destroy a rotor housing and exotic ceramic apex
seals. It looks like nikasil is not a fall back strategy for my
application. I did like the fact that the entire surface is coated evenly
with nikasil in a plating tank, but chipping makes it a no go. The
detonation gun coating sounds like our plasma spray with the electric
arc/compressed air being replaced with an oxygen acetylene explosion and
nitrogen purge cycle at high frequency. I can see that it would work,
however the only thing our shop had any success with was building up
bearing journals spinning in a lathe which were reground to size. Any
application requiring making consecutave passes didn't leave a surface I
would run side seals on. Aparently detonation gun coating works on a rotary
as a possible solution.

My original plan was to make the inner wear surface of nickel iron and the
rest of the housing out of magnesium which is still a good fall back plan.
Getting someone to cast the iron was problematic, and very few shops did
aluminum and magnesium as well as iron. The aluminum with 17% silicon
nodules still seems to be a good approach and has been done successfully in
mass production engines. I don't see a problem with TBO, however I can
resurface all but the center housings.

It is my understanding that a rotary doesn't have a catastropic failure
mode with the rotors stationary gears or E-shaft or anything that would
prevent it from turning long enough to get back on the ground
somewhere.Fuel system problems and occasionally loss of coolant appear to
be the root of most power outages. If a rotary will start it seems it will
run, and compression checks can turn up a wear issue before it becomes a
problem. This kind of maintenance seems best classified as inconvienant
compared to a connecting rod failure.
george grimes

What I wanted to know is how you managed to insert three blank lines
bwtween every line in the original message when you forwarded it? :)

Paul Lamar