Thanks Wayne, I will pass this along to the engineer types in the
discussion group, they most likely will comment further on any known
processes.
The Mazda Rotary did go to 3 piece apex seals but returned to 2 piece,
probably because their more robust. The Mazda apex seals were made of
different materials, but eventually settled on cast iron, probably with
some carbon as the top edge is laser hardened.
At first glance the silicone carbide seems to be the same process Ford
uses and it is a very good surface treatment - however the substrate
needs to have some density in depth, more than just aluminum or the
surface treatment just fails, no matter how hard. That's why Mazda went
to the steel liner, of course a natural selection of surface treatment
was then hard chrome (porous type, to hold some oil film). The silicone
carbide stands up to piston ring wear but not to apex, corner, and side
seal wear - which is much harsher. I might suggest that there is a
denser liner material on the RE5 rotor housings as a photo on the
housing seemed to show a liner much like the Mazda, but it may not be steel.
Again thanks for the info.
George Lendich
Hi George,
I do not have the time to go through the 6? thick notes that I have
on the RE5. Unfortunately, not only do I work away from home for
periods of a week or so, the nature of my work means that I am
unable to carry my notes with me so I have very limited
opportunities to read them. I also don?t want to give you
information off the top of my head particularly because you wish to
use it in a discussion. Just briefly, here are some basics:
Mitsuru Shimizu- RE5 development Engineering Controller:
?We applied what you know as C.E.M. (composite electro-chemical
materials) to plating the rotor housing. This plating is extremely
hard. And you have to polish this hard surface. With an ordinary
grindstone, it takes half a month !?
Shigeyasu Kamiya- RE5 Section Chief:
?Suzuki itself had been independently working hard on it (C.E.M.
process) and when it was ready for use we discovered that it had
been patented by an American firm. We now hold about 20 patents in
plating alone.?
Motorcyclist, January 1975:
?Apex seal wear was overcome by the new C.E.M. plating process
consisting of nickel-silicon carbide, the latter approaching the
hardness of diamonds and being corrosion resistant. For the apex
seals, Suzuki employed a special material called Ferro-Tic, a
combination of sintered ferrous alloy and titanium carbide having
only 1/12^th the wear of cast iron. Translating into miles/wear, the
apex seals in an engine that had been run 18,642 miles showed only
20 microns of wear. That?s .0008 of an inch.?
There is not much more intricate detail on the plating process
available. Most reviews and interview cover similar ground. I would
imagine that Suzuki deliberately limits the details as this was a
patented process that they had developed in house. I imagine that
you are aware of the apex seal design (three piece spring tensioned)
and I don?t really know if they are different in any significant way
to other rotary designs. I was aware that the Film that I sent you
contained little information on the plating process per se (possibly
for the aforementioned reasons) but I thought that it certainly had
entertainment and interest value giving some insight into the scale
of the project. Hope that some of this helps you.
Cheers,
Wayne.
Wayne,
I am back from my trip and received your DVD - Thanks again!
I'm still no clearer on the coating or process on the aluminium wear
surfaces. If you could advise me of this I would be eternally
grateful as we are having a discussion on this on a Rotary
discussion group..
George Lendich
------------------------------------------------------------------------
Bill Jepson,
Some more info on the RE5 rotary motorbike engine. I have heard of the
silicon carbide surface treatment, but not heard of the nickel-silicon
carbide, is that the same thing.
Also the apex seal material seems interesting-any comment?
I'm wondering if this is what others are using?
George ( down under)
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