X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [64.129.170.194] (HELO VIRCOM1.fcdata.private) by logan.com (CommuniGate Pro SMTP 5.4c2o) with ESMTP id 4872488 for flyrotary@lancaironline.net; Wed, 16 Feb 2011 11:52:29 -0500 Received-SPF: none receiver=logan.com; client-ip=64.129.170.194; envelope-from=cbarber@texasattorney.net Received: from FCD-MAIL06.FCDATA.PRIVATE ([fe80::697f:d6aa:b87:78d8]) by FCD-MAIL05.FCDATA.PRIVATE ([fe80::809d:a06e:5913:452e%15]) with mapi id 14.01.0270.001; Wed, 16 Feb 2011 10:47:37 -0600 From: Chris Barber To: Rotary motors in aircraft Subject: RE: [FlyRotary] Re: Ceramic Apex Seals....curiosityREceramin/carbon/steelst Thread-Topic: [FlyRotary] Re: Ceramic Apex Seals....curiosityREceramin/carbon/steelst Thread-Index: AQHLzeG5vLEsLAd9JkCLrVhfM/sa7pQEVEdO Date: Wed, 16 Feb 2011 16:51:49 +0000 Message-ID: <2D41F9BF3B5F9842B164AF93214F3D303572AC97@FCD-MAIL06.FCDATA.PRIVATE> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [166.139.76.11] Content-Type: multipart/alternative; boundary="_000_2D41F9BF3B5F9842B164AF93214F3D303572AC97FCDMAIL06FCDATA_" MIME-Version: 1.0 --_000_2D41F9BF3B5F9842B164AF93214F3D303572AC97FCDMAIL06FCDATA_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks Tracy (and all), That is kinda what I was looking for, just a quick rundown. I have left a message with Laura to get my new seals. I am pretty certain that my current issue is likely due to bent seals as Tr= acy has mentioned, thus keeping the compression low in the rear chamber. IIRC, the Haynes manual calls for 80 psi, which is what I am getting in the= front chamber. But I am only getting 60 psi in the rear. Since I am conf= idant in my assembly, the bent seals seem to fit the evidence. To address = Lynn's comments, yes, I do have an IVO three blade prop turning and two non= -auto batteries for power. Thus, the not coming up to 100 psi as Lynn ment= ioned, seems expected under load. I would love to have gotten the apex seals (and O-rings) to use this weeken= d, but shipping, while good, it not quite that good. Once I get the parts, = the tasks should go fairly quickly. The hard part is getting out to the han= gar. I am the caretaker for my mom (cancer and bad spine) and I have to wo= rk around doctor appointments. etc. I hope to get the time to first try new plugs...and then tear down the engi= ne to confirm my suspicions. Chris Houston ________________________________ From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of = Tracy [tracy@rotaryaviation.com] Sent: Wednesday, February 16, 2011 8:02 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Ceramic Apex Seals....curiosityREceramin/carbon/st= eelst What I know (and don't know) about apex seals: I have never used ceramic seals but I do talk to a lot of car racers who ha= ve. (98% of RWS customers are car guys, not aviation folks). The Pros: From their feedback it sounds like ceramics will last virtually= forever, their lower weight allows higher rpm limits and they are kind to = the chrome on rotor housings. The Cons: They are strong but brittle. Detonation in turbo engines will b= reak them just like stock seals. Worn out rotor grooves will break them in= NA engines. They cost a lot. If I were building an engine that had nice fresh parts AND had an extra $18= 00.00 to spare, I'd use ceramics but only for the feel good / cool factor. I have used stock and RA seals and never come close to wearing either of th= em out. Stock seals were worn about 30% of allowable limits after 956 hour= s of flight time. RA seals were about 25% worn after 560 hours of flight. = I do not know the percentage of wear that happens during break-in period b= ut it's probably not linear. Rotary engines have a longer break-in period= than piston engines based on the compression tests I've run at annuals. M= ine took 250 hours to get highest compression readings. The new 2 piece st= ock seals will probably last a bit longer than RA seals but if anything bad= does happen to stock seals (fracture due to rotor wear, FOD, detonation, e= tc) they take expensive parts along for the ride. RA seals can and do fai= l but the failure modes are non destructive to other parts of the engine. = That is the main reason why the car guys use them. They would not care if = the wear life were only 50% of stock because they never expect to get anywh= ere close to that. Tracy On Tue, Feb 15, 2011 at 8:29 PM, Dustin Lobner > wrote: For what it's worth, I called Adam at www.rotaryengines.com and had a half hour discussion with him about things. He wa= s remarkably open about putting it in an aircraft (a lot of other places wo= n't give you the time of day if they hear "aircraft" as I'm sure some of yo= u know). I said that for an aircraft he wouldn't put in ceramics because t= hey're more there for super-high stress situations like drag racing, but fo= r an aircraft the cost:benefit ratio isn't there. Plus, he's not 100% conv= inced on the reliability. Dustin On Tue, Feb 15, 2011 at 6:26 PM, > wrote: In a message dated 2/15/2011 11:58:49 A.M. Eastern Standard Time, cbarber@t= exasattorney.net writes: Heck, tearing down my engine seems to be a routine event as of late 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 i= n 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 disc= arded 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 st= eel seals. Ceramics are so light that you cannot help but grin when you pic= k 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 al= l 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 applicati= ons, 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 col= d starting. Mazda competition sells racing ceramics, probably Linetties. There are othe= r manufacturers. Here is one. http://www.nrsrotorsports.com/ Lynn E. Hanover --_000_2D41F9BF3B5F9842B164AF93214F3D303572AC97FCDMAIL06FCDATA_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Thanks Tracy (and all),

 

That is kinda what I was looking for, just a q= uick rundown.

 

I have left a message with Laura to get my new seals. 

 

I am pretty certain that my current issue is likely due to bent seals as= Tracy has mentioned, thus keeping the compression low in the rear cha= mber.

 

IIRC, the Haynes manual calls for 80 psi, which is = what I am getting in the front chamber.  But I am only get= ting 60 psi in the rear.  Since I am confidant in my assembly, the ben= t seals seem to fit the evidence.  To address Lynn's comments, yes, I do have an IVO three blade prop= turning and two non-auto batteries for power.  Thus, the not coming u= p to 100 psi as Lynn mentioned, seems expected under load.

 

I would love to have gotten the apex seals (and O-rings= ) to use this weekend, but shipping, while good, it not quite that goo= d. Once I get the parts, the tasks should go fairly quickly. The hard = part is getting out to the hangar.  I am the caretaker for my mom (cancer and bad spine) and I have to work around doctor appoint= ments. etc.

 

I hope to get the time to first try new plugs...and then tear down the e= ngine to confirm my suspicions.

 

Chris

Houston

From: Rotary motors in aircraft [flyrotary= @lancaironline.net] on behalf of Tracy [tracy@rotaryaviation.com]
Sent: Wednesday, February 16, 2011 8:02 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Ceramic Apex Seals....curiosityREceramin/ca= rbon/steelst

What I know (and don't know) about apex seals:

I have never used ceramic seals but I do talk to a lot of car racers who ha= ve. (98%  of RWS customers are car guys, not aviation folks).

The Pros:   From their feedback it sounds like ceramics will last= virtually forever, their lower weight allows higher rpm limits and they ar= e kind to the chrome on rotor housings.

The Cons:  They are strong but brittle.  Detonation in turbo engi= nes will break them just like stock seals.  Worn out rotor grooves wil= l break them in NA engines.   They cost a lot.

If I were building an engine that had nice fresh parts AND had an extra $18= 00.00 to spare, I'd use ceramics but only for the feel good / cool factor.&= nbsp;
I have used stock and RA seals and never come close to wearing either of th= em out.  Stock seals were worn about 30% of allowable limits after 956= hours of flight time.  RA seals were about 25% worn after 560 hours o= f flight.  I do not know the percentage of wear that happens during break-in period but it's probably not linear. &nb= sp; Rotary engines have a longer break-in period than piston engines based = on the compression tests I've run at annuals.  Mine took 250 hours to = get highest compression readings.  The new 2 piece stock seals will probably last a bit longer than RA seals but if a= nything bad does happen to stock seals (fracture due to rotor wear, FOD, de= tonation, etc) they take expensive parts along for the ride.   RA= seals can and do fail but the failure modes are non destructive to other parts of the engine.  That is the main r= eason why the car guys use them.  They would not care if the wear life= were only 50% of stock because they never expect to get anywhere close to = that.

Tracy

On Tue, Feb 15, 2011 at 8:29 PM, Dustin Lobner <= span dir=3D"ltr"> <dmlobner@gmail.= com> wrote:
For what it's worth, I called Adam at www.rotaryengines.com and had a half hour discussion with him about thi= ngs.  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&qu= ot; 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 cos= t:benefit ratio isn't there.  Plus, he's not 100% convinced on the rel= iability.

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.<= br>
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 tool= ing in the form of ceramic triangles that clamp into tool holders. It mater= s 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 rac= ing. Stronger than steel. Oblivious to high temperatures.
And for racing, track the housing shape at any RPM, using doubled spri= ngs, 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 ov= er 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 i= n the muffler. But not for long.
 
I have read that RA seals also hold up well. Ceramics are used in near= ly all pro racing applications.
 
I sold a used set to another racer for $500.00. They were identic= al to new seals after two years of service.
 
The down side is cost. And for one piece seals, typical of racing appl= ications, you must be sure you have the minimum end clearance, about .0015&= quot;.
 
There have been efforts to develop a two piece seal that is less sensi= tive to length variations, as they run at zero end clearance for much bette= r cold starting.
 
Mazda competition sells racing ceramics, probably Linetties. There are= other manufacturers.
 
Here is one.
 
 
Lynn E. Hanover


--_000_2D41F9BF3B5F9842B164AF93214F3D303572AC97FCDMAIL06FCDATA_--