Paul,
    I'm wondering if the engines that had problems also had lapped side
    housings.  It looked to me that at least one of the TES o-rings were
    pinched and later failed.  If you grind/lap the side housings a few
    thousandths, wouldn't you need to change to smaller cross-section
    o-rings?

    BTW, my TES o-rings were easy to install, once I got the correct
    lengths.  No leaks either, and I'm running a 25# pressure cap.  I used
    Hylomar to hold them in place.  The guys on the No Pistons list talk
    about using Vaseline.  Maybe that's why they're having trouble?  Just a
    guess...

    Mark St.

    A few thou should not make a difference. 10 thou or more is another
    matter.
    Vaseline is the Mazda recommended stuff. The main seal is metal to metal
    as Hylomar won't take that heat directly. I know people use it and
    get away with it but I would not recommend it for this application.

    The O-rings are there to keep the coolant in the water jacket and
    not seal the combustion gases. However even the stock square seals
    have a
    layer of Teflon on one side. Mazda calls it white paint in the shop
    manuals
    but it is Teflon which becomes obvious when they are removed from a
    used engine.
    The Teflon goes on the OUTSIDE of the seal because of the exhaust gases
    recirculated in the rotor and end housings are very close to the
    O-rings... I think.

    No oil is allowed on the silcone rubber as silcone is attacked by
    hydro carbons. That is another reason TES O-rings are better.

    Paul Lamar ...No rotor no motor.


Reminder..  Please sign your posts..

Thanks,

Matt-

Hi guys,

I'm still a member of this newsletter.  Have been since 1998.  Since I'm
finally responding to the few  posts, I'd like to have a chance to defend
myself against a couple of things that were said as well as comment about
the original thread I created on NoPistons.com.

I'm not a shill.  Never heard the term before, but based on Paul's
explanation, it doesn't fit me in the slightest.  I'm a personal business
owner and have been for 5 years.  I have no particular relationship
with any other business that would otherwise preclude me being
someone who'd commit some sort  of product espionage or false
advertisement, etc.  Quite frankly, that's ridiculous.  I'm a guy
who builds rotary engines for the street car enthusiast as well as a
guy who travels the nation tuning these things typically for power
production.  My interests therefore involve the use of good, high
quality products.  "I don't build junk" is a phrase I use with most
people who've never met me who are also considering doing business
with me.  My name is too important to me to be put on stuff that I've
built that'll fall apart in short order.  I take my work very seriously.
This
is what I live to do.

Which leads me to the reasons why I posted what I did about the
Rotary Aviation o-ring set.  There's no malice intended here.  I don't
have any personal beef against Laura or Tracy Crook; on the contrary,
they seem like real nice people.  There's also no promotion of another
product by way of proxy here.  It's a  straight-up, customer-oriented
review of their o-ring product.  Up until fall of last year, I was a very
consistent user of their o-ring kit and had been since late '03.  I'd used
them in almost every engine I'd built in that period of time.  In my
opinion,
based on the steady use of their product for that nearly 3-year period of
time,
I think it makes me a pretty good customer and certainly someone who's
worthy to give his input.  Their response to my complaint wasn't reasonable,
at least whomever the person was who responded to the individual on that
forum that forwarded them the thread wasn't.  I would think the proper
one would be somewhere in the neighborhood of  wanting to in the least
take a look at the issue and see if it has merit, let alone take measures to
fix the problem so it doesn't occur again.

Paul, what kind of details am I leaving out?  I thought I'd described
this failure and my theories behind why quite well.  I feel as if the
array of pictures I've posted speak for themselves.  Is there something
else that you'd like to know about that might help form a better opinion?

You also mentioned that I should be storing (forming) these o-rings
around a wooden template as per pictured on your website.
http://www.rotaryeng.net/O-ring-size2.html Like I've already mentioned,
why in the world should I?  Do you see any information on their website
that demands any such thing? http://www.rotaryaviation.com/o-ring_kits.htm
I sure don't.  Let's look at a couple of other factors:  One, this o-ring
kit is
made to be easily purchased.  They've got Paypal links on there.
Secondly, it's evident that these kits are targeted for not just the
aircraft
guys but also car guys like myself.  Therefore, the target market is much
more broad and encompassing.  If there's supposed to be some sort of
instruction when it comes to the "proper" installation of these o-rings,
given the target market, does it seem therefore reasonable that they're
at fault for not providing that said instruction?  They're selling the
product;
it's their responsibility to serve their market rightly.  How in the world
can
a guy like me or anyone else for that matter be blamed for their o-rings
going bad, all the while ignoring the clear evidence of the Teflon
jacketing
splitting  long-ways for no apparent reason?  I'm not at fault for not
building
some wooden template.  I can't read minds, and when I buy a product
that's clearly advertised for the engine I'm using, that lacks *any* other
(allegedly) critical information regarding its installation and use, why
should I
be held responsible?  That's silly.

I don't know who the manufacturer of these o-rings is and quite frankly
I don't care.  I'm an engine builder and a customer and I demand
satisfaction from not only what I buy for myself but also
what I buy and therefore build for others that has my name on it.  I'm still
very upset from the fact that I've had to shell out money of my own to
repair several engines now (the count is up to 7) because of the glaringly
obvious defect of this product, whether it be a material or  application
error.
Having to tear a motor apart because of an o-ring that splits along the
edge,
having nothing to do with installation, is just absurd. I'm also still upset
at RA's very arrogant and condescending  response to my complaint about
their product, implying that since I'm not a "commercial builder", or
however they exactly characterized it, and since they've only seen some ridiculous
"0.001% failure rate" that my complaint (implicitly) therefore doesn't
matter. What hogwash.

Someone mentioned that I seem reasonable.  I like to think I am as
I believe the strength of an argument rests solely on its merits.  Here's
a (hopefully) reasonable question, I think:  Given the  vastly higher
standard of quality and workmanship that's demanded in aircraft use
vs. that of automotive, wouldn't it be reasonable to suggest that not
only these o-rings be applied (or manufactured, whichever it is) correctly,
but also be sold and delivered in a way that's replete with this said
"instruction" of forming them for the factory o-ring land and anything
else for that matter?? You guys are using these in airplanes, for crying
out loud.  Have an odd overheating symptom that produces an out-of-nowhere,
symptomatically stratospheric water temp or rock-hard radiator hoses for
no apparent reason?

Good luck pulling over to check why while at 10,000ft.

B
___________________________________________________________________________
Brian D. Cain -/- Dallas/Ft. Worth, TX -/- bdc@bdcmotorsports.com
BDC Motorsports | Performance Rotary Engines, Specialized Porting, EFI
System Installation & Tuning
http://www.bdcmotorsports.com -/- http://bdc.cyberosity.com


The only missing information I need to know about Brian is the exact
section diameter of the O-rings shipped to you. I would like to know
who supplied them to Tracy so we can avoid that source but so far
he is not fourth coming with that info. I have in the past recommended
only Creavey as we had some bad results with McMaster Carr.

Again I am sorry about the bad things I said about you after reading
the no pistons post.

Paul Lamar ...No rotor no motor.

B,

You are obviously more experienced with rotaries than I am, but I am also
self employed and take my work seriously. I have screwed up a few times and
I have paid for the mistakes of others to protect my name in my business. It
sucks but it is a cost of doing business and earning a reputation that means
something. I clipped  a few quotes out of your last post  that contradict
each other. The first three are at odds with the last five.

"I don't build junk"
My name is too important to me
I take my work very seriously.


Like I've already mentioned, why in the world should I?
Do you see any information on their website that demands any such thing?
I'm not at fault for not building some wooden template.
why should I be held responsible?  That's silly.

I don't know who the manufacturer of these o-rings is and quite frankly I
don't care."

The reason to form the seals on the board and to care who the manufacturer
is, is to be able to make the first three claims. It is also why you need to
measure accurately the ring diameter before installation. You can't control
the quality of your product going out if you don't control it going in.
Maybe I'm just lucky in that I found these two important tricks before it
mattered to me. I'm sure you have lots of tricks that you employ in putting
these together that aren't in the manual or printed on the parts box, but
that doesn't mean you don't use them.


John Gibbons

Hi John;
I have to side with Brian on this one.

<RANT>
He bought a product with the expectation it would be superior to the
stock orings - and has been burned big time...
Do you have to double check everything from everyone?
Have you reversed engineered Tracy's redrive? checked everything for
proper heat treating?
In fact, what testing was performed on anything??? care to share the data?
Have you looked at C6/E4OD planetary's, many look like rejects from
other car manufacturers...
How many "superior" aftermarket rotary engine products have appeared in
the last few years?
TES orings, apex seals, ceramic coatings...

I DO mean to sound harsh.  I like Tracy and Laura - they are
entrepreneurial pioneers.  BUT, This is EXPERIMENTAL
automotive/aviation and (mass) long term product testing has not been
performed...except by Mazda.

How many people even bothered to measure the size of orings themselves?
how many posted them?  I DID.
There could be hundreds or thousands of engines affected.

Brian has been kind enough to share his experiences with us and alert us
to a potential problem.  It might
even save someones life...I appreciate your feedback Brian - Thank you!
Check his contributions on nopistons.com

Properly sized, these TES orings sound better on paper in many
respects.  The higher temperature "might"
provide an extra overheat margin.
Properly sized, they should not need to be stretched on a form at all...
Formed to shape would be nice - but these are off the shelf orings.
The question always arises as to whether any automotive component is
driven by cost reduction or quality.
Remember:  Better is the enemy of good.  In this case, I now believe we
have a solution in search of a problem.

I had a chance to measure a used set of Rotary Aviation TES orings a few
months back when cracking an engine.
I (stupidly) did not write down the measurements.  I do recall they were
quite a bit larger than 0.093" for the inner oring.
There was quite a bit of discussion about this years ago here.

Let's try to be a little scientific about this:
CAN SOMEONE MEASURE A NEW SET!

Based on Brian's nopistons pics, I would guess that the orings were too
large a diameter and at higher temperature opened up
enough of a gap between the housings to be exposed directly to the
exhaust gases and split (long before stock orings normally would).
<RANT~>

Here are a few pics of various housings I had handy this evening, with
the same oring, in this case .093" x 9.000 ID PFA inner oring from Creavey.
TES-S591NA- oring fits like a snug glove, does not require anything to
stretch or hold it in place.  It can turned upside down and shaken hard...
TES-S3-12A - oring fits like a slightly loose glove after the previous,
stays in place upside down and shaken.
TES-S4-87NA - usual PITA, will not sit until I have stretched it
repeatedly, guaranteed to fall out without halomar or vaseline in the
groove, possibly even then.
Same as other 86-88 NAs.
BTW - Mazda's engine assembly petroleum jelly supposedly has the
consistency of Vaseline out of the freezer.
TES-S6-93T - also a PITA, same as previous.
It appears that the inner oring groove castings differs between
generations...

BTW, the post I made months ago regarding rotor letter codes...If you
are mixing and matching rotors, I would weigh them...
My (new) gram accuracy scale, in a small sample, has shown rotors with
the same letter code "may" NOT be a good match...
(contrary to accepted common knowledge)

Running out of "..."

-Cheers
Cary

Paul,
There are two methods in common use for applying the Teflon coating to a
cylindrical substrate.  An older method involves a spiral or helical
wrap of  Teflon ribbon.  When the wrap is complete, the adjoining edges
of  ribbon are fused someway to form a continuous covering.  If one
examines a variety of Teflon insulated wire samples some will clearly
show this helical wrap pattern in the insulation.  A newer method that
is more difficult and more costly involves extruding the Teflon onto the
surface of the substrate to form a continuous and seamless coating.

The cracks that are apparent in these two photos that Brian posted seem
to indicate a helical pattern.  Rotary Aviation could have received a
batch of defective O-ring material or received the wrong material
(wrapped instead of extruded).  It may be worthwhile to destructively
test some samples of  TES O-ring material to see if cracks similar to
those shown in Brian's photos can be produced.

Aubrey Thompson

In the case of Creavey I think the Teflon is extruded first and the
silicone
is
injected in the liquid state. This is probably done in a mold so the
pressure
required to inject the silicone does not expand the Teflon. I could be
wrong.
On the  other hand I think air may be required to convert liquid silicone
to
the rubber state. That is why they call it RTV or Room Temperature
Vulcanizing
I think.

These picture you attached look like very poor workmanship was used to
make
these O-rings.
I have never seen a TES O-ring that looked anywhere near that bad
including
the
ones we bought from McMaster car. Creavey quality control on the other
hand
is
excellent. It is on the cool side of the engine as well. The O-rings look
to
be the proper cross section size however. Perhaps they were well under
diameter
and somebody stretched them to fit. If you try to do this one section of
the Teflon will yield while the rest of it remains the same. Perhaps this
is what happened some where along the line.

I have always thought of rubber, and that includes silicone, as being
"compressible".
What has been brought home to me after reading some bad O-ring experiences
years ago
is; rubber is no more "compressible" than hydraulic fluid. Furthermore
silicone expands
greatly when heated. If it is contained in a closed chamber without
expansion room such as an
O-ring slot it will generate tremendous forces. Enough to crack cast iron
and bend steel.
Therefore it is extremely important to have the right section diameter
when
installing
O-rings.

If the O-ring is oversize for the slot the process of tightening down the
tension
bolts will cause the hydraulic force of the rubber to break the cast iron
end housings.
The problem will compound itself when the engine is warmed up to operating
temperature
as the silicone expands.

The last picture is what happens when the TES O-ring is too large in
section
diameter for the size of the slot. You can see that the Teflon was cold
extruded
into the space between housings prior to final torquing of the tension
bolts.
The date on this photo is March 2003.

Paul Lamar ...No rotor no motor.



Now I'm getting very concerned! I've installed these o rings in my 20B and
now I'm wondering if I should tear it down and replace them with factory o
rings. I'm getting very close to my engine installation and would rather
do
it now than after the installation. Do we know of success stories with
these
o rings? Or should I just change them...

Bob Mears
Supermarine Spitfire

Bob,
I installed Creavy TES o-rings about 4-5 years ago.  While I've only got
about 25 hours on the engine, there is no sign of leakage to date.  We'll
see how things develop.  Where did you get your TES o-rings?

Mark St.

I am about to put an engine together, so I need some TES o-rings as well as
the full overhaul kit (engine only). I have searched the web, but without
any assurance that I will get Creavy o-rings. Can anybody recommend a vendor
who sells the full overhaul kit with TES o-rings and stock Mazda apex seals?
Or can I get the stock apex seals only from Mazda?

Doc Custer
Retired Software Engineer and sometime Audiologist

I don't think there is one. Buy the stock overhaul kit from Bob Mears
Mazda or Mazdtrix and buy the O-rings from Creavey. You might be able to
sell the stock O-rings on ebay. Mazdatrix also sells the stock apex seals
and stock overhaul kit for that matter.

BTW TES O-rings are not essential for aircraft use.

They just give a bit of a better over heating margin and are reusable.
The knowledge on what it takes to improve the rotary cooling system has
advanced greatly in the past ten years so airplanes are now flying
with no cooling problems from the get go. The stock inner water cooling
ring is coated with Teflon on one side with the rest silicone. They work
fine in most cases.

One place that they could still pay off is in the oil scraper rings
on the sides of the rotors. Chuck Dunlap has been flying with those
for a few years. That is a compromise with all TES O-rings.

I drove my Cosmo for years with these melted out. Smoked like
a smelter for years when I started it up but other than
a little extra oil consumption I experienced no other problems.