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Shipchief/Mike,
I can't see a response from Bill- yet, but I feel I
should respond.
The aggressive corner and side seals take a toll on
even the niterited iron housings, which so far has proven to be the best surface
so far. The next best surface is the det gun surface, whereby steel is
blasted into the surface of aluminium. From my knowledge all other
surfaces fail, no matter how hard because of the soft substrate nature of
aluminium.
What Bill is talking about is chrome molly
housings, precision water jet cut and the pieces then oven
brazed in one process , the wear surface then nitrated, very strong
very light and a brilliant wear surface.
It has the disadvantage of being 1lb heavier than
the aluminium housings but much stronger and wears much better.
All Al housing have the disadvantage of being
cast and not as strong/ dense as 6061. therefore it doesn't offer up a good
substrate. It will be interesting to see how Mazda solved the problem.
Mistral tried everything and when I last talked to them most everything
they tried -failed, last thing I heard was they were considering a
specialty alloy for the housing.
George ( down under)
I'm thinking an aluminum plate of 6061
could be cut, drilled, milled, then the wear faces "Nikasil" equivalent
electroplated.
Is that fairly straightforward if P Ported?
-----Original
Message----- From: Mike Wills < rv-4mike@cox.net> To: Rotary motors
in aircraft < flyrotary@lancaironline.net> Sent:
Tue, Apr 20, 2010 7:22 pm Subject: [FlyRotary] Re: cooling for ground
runs
Bill,
You mention "steel side plates that will weigh
1 pound more than the aluminum side plates...." Are you talking about the 3
intermediate iron housings? If not, what are you talking about?
What is it that makes replicating the iron
housings in aluminum so difficult? I realize there is a potential wear
issue, but is there no relatively inexpensive means to produce these housings
with a hardened or treated wear surface that will survive while otherwise
replicating the stock configuration?
Seems to me that the hot ticket would be a PP
configured engine with all aluminum housings, but otherwise standard
Mazda configuration so that it would be plug and play compatible with the
stock engine and would use standard available parts (like Tracy's PSRU). That
is an engine I'd pay good money for and would seem to hit the sweet spot in
providing potentially more power with less weight than the typical 4
cylinder Lyc, without all of the budget busting unobtanium of the
original Superlight engine. And I think that is what Brian is getting at. No
coincidence that both of us have overweight RV-4s and would like to take some
weight off. What am I missing?
Mike Wills
Sent: Sunday, April 18, 2010 10:58 PM
Subject: [FlyRotary] Re: cooling for ground runs
In a message dated 4/18/2010 7:50:30 PM Pacific Daylight Time, Bktrub@aol.com writes:
What were the original powersport superlight engines? 13B p-port,
with the oil pan mounting flanges cut off, aluminum side housings,
mounted with the exhaust side down? I'm sure there's more to them than that,
but I think that's what they were, basically.
II would have liked to see Powersport make just the engines- forget the
whole package- if the engine is light, powerful, and reliable, then
homebuilders will do the rest.
Just my two cents.
Brian Trubee
Brian,
So you can get the straight scoop I'll talk about this. The
"Superlite" engine used HIGHLY modified standard Mazda rotor housings. Almost
every other part was custom. Water inlet location was changed. ALL center and
end plates were aluminum with coatings. The engine used p-ports done the way
they have always done, using o-ring seals. Once done this way they never had
leak problems because the o-rings are designed to handle the heat cycle. The
PSRU was a custom built planetary with a pendrolus damper to move harmonics
outside the operating range. The previously mentioned Mazda housings were
reversed and the engine ran backward so the prop would turn the "right" way.
The engine was plugs up and dry sump from the begining. An absolutely
astounding piece of work. That said they would be too expensive to sell today.
Please remember that this was before Powersport was sold to Ratek Machine in
Wisconsin. I don't know if they are still producing anything or not.
Steve has come to me to work to save some of the ideas and update
them so there won't be any intention of using the designs exactly as done
before. Our intention is to produce parts to pay for the cost of making them
for ourselves with the potential of it becoming a full business much later.
There is the possibility of making a complete engine, but for now only the
parts. One item of interest is a steel side plate for the converted
standard engine that weighs only 1 pound more than the aluminum side plates,
but can still be nitrided just like the standard sideplate. These will be for
p-ported engines only as there won't be any side ports built in. We also want
to make a similar lightweight 20B intermediate housing for 3 rotors using a
standard e-shaft. The standard one weighs 45 pounds and even those have become
unobtainium lately. It must be the rolex 24 hour racers using them up. I have
a local shop quoting the parts as we produce models and drawings as we want
them to be. That is all I can say for now, I'll keep the group posted as we
make progress.
Bill Jepson
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