Mailing List flyrotary@lancaironline.net Message #53872
From: wrjjrs@aol.com <wrjjrs@aol.com>
Subject: Re: [FlyRotary] Re: Ceramic Apex Seals....curiosity REceramin/carbon/steelst
Date: Tue, 15 Feb 2011 20:23:37 -0800
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Dustin,
The Mazda factory LeMans winning 4 rotor used the Ianetti ceramic apex seals. In the post race teardown they measured negible wear on the ceramic seals. That is as good a test of endurance as you can get. The Ianetti seals are the best you can get period. I would love to find a half price version.
Bill Jepson

Sent via DROID on Verizon Wireless


-----Original message-----
From: Dustin Lobner <dmlobner@gmail.com>
To:
Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent:
Wed, Feb 16, 2011 01:30:26 GMT+00:00
Subject:
[FlyRotary] Re: Ceramic Apex Seals....curiosity REceramin/carbon/steelst

For what it's worth, I called Adam at www.rotaryengines.com and had a half hour discussion with him about things.  He was remarkably open about putting it in an aircraft (a lot of other places won't give you the time of day if they hear "aircraft" as I'm sure some of you know).  I said that for an aircraft he wouldn't put in ceramics because they're more there for super-high stress situations like drag racing, but for an aircraft the cost:benefit ratio isn't there.  Plus, he's not 100% convinced on the reliability.

Dustin

On Tue, Feb 15, 2011 at 6:26 PM, <Lehanover@aol.com> wrote:
In a message dated 2/15/2011 11:58:49 A.M. Eastern Standard Time, cbarber@texasattorney.net writes:
Heck, tearing down my engine seems to be a routine event as of late <sigh>

That was my understanding too....about being nicer to the housings.

I was just wondering about what I don't know or what could be expanded on.

Like Dave said, minding parameters is the proper course but I would like to have as clear an understanding as possible for my own edification.

 
Ceramics have now come of age in many areas. Any machine shop has tooling in the form of ceramic triangles that clamp into tool holders. It maters not if the work piece is heat treated, or harder than Chinese arithmetic, the ceramic bits go through it like it was butter. The bits are cheap, and discarded if fouled or dulled.
 
Ceramic apex seals are the gold standard of apex seals. No detectible wear on the seals or the housing chrome. In our case for two seasons of racing. Stronger than steel. Oblivious to high temperatures.
And for racing, track the housing shape at any RPM, using doubled springs, and even with twice the spring pressure, have less than half the drag of a carbon seal, and far less than stock steel seals. An automatic 5 HP over steel seals. Ceramics are so light that you cannot help but grin when you pick one up.
 
Ceramics do survive detonation events that would put all steel seals in the muffler. But not for long.
 
I have read that RA seals also hold up well. Ceramics are used in nearly all pro racing applications.
 
I sold a used set to another racer for $500.00. They were identical to new seals after two years of service.
 
The down side is cost. And for one piece seals, typical of racing applications, you must be sure you have the minimum end clearance, about .0015".
 
There have been efforts to develop a two piece seal that is less sensitive to length variations, as they run at zero end clearance for much better cold starting.
 
Mazda competition sells racing ceramics, probably Linetties. There are other manufacturers.
 
Here is one.
 
 
Lynn E. Hanover

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