Return-Path: Received: from [24.25.9.103] (HELO ms-smtp-04-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.3c3) with ESMTP id 881787 for flyrotary@lancaironline.net; Mon, 18 Apr 2005 08:39:12 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-185-127.carolina.res.rr.com [24.74.185.127]) by ms-smtp-04-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id j3ICcKL5027785 for ; Mon, 18 Apr 2005 08:38:24 -0400 (EDT) Message-ID: <00b901c54413$81363d10$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Apex Slot Limits Date: Mon, 18 Apr 2005 08:38:20 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_00B6_01C543F1.F9EDAE90" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_00B6_01C543F1.F9EDAE90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable No Georges, no tools missing - had not done any work on the engine for a = number of flights. Nothing of a "diamond" shape has come to mind either = {:>).=20 Beware! the fact that a seal slot is worn will not keep you from = having compression, if the seal is still being pressed against the rotor = housing. So that is not necessarily a good test of slot wear - the = problem is slot wear changes the magnitude and angle of forces mix = acting on the apex seal. If they get to a certain point, they can = fracture the rather brittle apex seal. =20 I am fairly certain that the wear limits on the slots specified by = Mazda are there for a good reason. If the seals are approx 1.91 mm wide = and the bottom of the slots appear to be around 1.98 wide then the new = seal in the new slot have a clearance of about 1.98 - 1.91 =3D 0.07 mm. = And as you can see from the specs taken from the Mazda workshop manual = that is well within the standard (near the lower end). To stay with the = maximum Limit spec (0.15mm) the slot should be no wider than 1.91 + 0.15 = =3D 2.06mm. So when you have slots measuring 2.16 to 2.43 mm wide, its = clear to me that they are WAY beyond the limit. You of course can = choose to accept that and perhaps for an auto I would as well - but not = me - not for an aircraft use. =20 Clearance of apex seal and rotor groove =20 Standard 0.0024 to 0.004 in (0.062 to 0.102mm) =20 Limit 0.006 in (0.15mm) =20 Of course, apex seals won't cause the engine to smoke, bad oil = seal/rings will. But, I assume you mentioned that as an indication of = the good condition the engine was in. It may be running well now, but = the question is how much longer would it have run. In auto use perhaps = for quite a spell - in aircraft use perhaps less, who knows for certain? I clearly do not have decades of rotary engine experience, but I do = believe that the engine manufacture probably has good reason for limits = in specifications. If you are near, but within the limits you should be = OK, but when you get way past the limit then you are on borrowed time as = they say. Just my opinion of course. One of the reason I am going with Tracy Crooks apex seals is to get a = much stronger, non-brittle seal. I saw a big man try to break one of = Tracy's seals by pressing it against the corner of a table and using his = weight to break the seal. A normal stock seal you can break with your = hands (use gloves if trying) but after apply all his weight several = times it began to bend and finally broke - but it was an impressive = display of how strong those seals were. Ed A ----- Original Message -----=20 From: Echo Lake Fishing Resort (Georges Boucher)=20 To: Rotary motors in aircraft=20 Sent: Monday, April 18, 2005 1:10 AM Subject: [FlyRotary] Re: New rotors, New housings Hi! Ed I took another 91 13b NA apart today, it had good compression on = a gauge six good pops at the exhaust port when rotated by hand, didn't = smoke & ran well . The slots were 2.26 to 2.43 wide, the apex seals worn = concave by about0.15mm on each side. by the wear on the eccentric shaft = bearings this engine had spent a lot of time at high revs. I doubt very = much that your engine demise was called by seal clearances, You are not = missing any tools by any chance? Georges Boucher -------Original Message------- From: Rotary motors in aircraft Date: 04/17/05 12:35:17 To: Rotary motors in aircraft Subject: [FlyRotary] Re: New rotors, New housings I do know that my worn slots measured 1.98 mm at the bottom and = range from 2.16 to 2.26mm at the top - giving an out of vertical of from = 0.18 to 0.28 mm. The specs say a maximum feeler gauge between an = inserted apex seal and wall is given as 0.15mm, I could insert an 0.18 = mm feeler in some and an 0.15mm in all. I don't think I would feel = comfortable flying with a rotary in that shape (anymore {:>)). Putting = them in an auto is a different story - if it breaks - park on side of = the road rather than strain the eyeballs looking for an airpatch. Ed A ----- Original Message -----=20 From: Echo Lake Fishing Resort (Georges Boucher)=20 To: Rotary motors in aircraft=20 Sent: Sunday, April 17, 2005 3:24 PM Subject: [FlyRotary] Re: New rotors, New housings Ken I screwed up on reporting the rotor slot width, it = should be 2.17 to 2.26mm not 2.017 to 2.026mm Georges=20 -------Original Message------- From: Rotary motors in aircraft Date: 04/17/05 07:51:53 To: Rotary motors in aircraft Subject: [FlyRotary] Re: New rotors, New housings -------------- Original message from keltro@att.net (Kelly = Troyer): --------------=20 Georges, Are these numbers in reference to the apex seal slot = taper from=20 the bottom of slot (2.017 mm) to the top of slot (2.026 = mm) which is a taper of (.009 mm) or about 3.54 thousands here in = the 48 ?? -- Kelly Troyer=20 Dyke Delta/13B/RD1C/EC2=20 -------------- Original message from "Echo Lake Fishing = Resort (Georges Boucher)" : --------------=20 Correction, the readings were 2.017 to 2.026mm Georges =20 -------Original Message------- From: Rotary motors in aircraft Date: 04/16/05 19:05:31 To: Rotary motors in aircraft Subject: [FlyRotary] Re: New rotors, New housings Hi! Ken Do you you cut on a taper, where does your = taper start? or do you just skim 0.015" off each side for a total of = 0.030". I just measured the two rotors that were in a "GOOD" running 92 = 13b NA & got a reading of 0.017 to 0.026mm, I guess they are toast. Georges Boucher -------Original Message------- =20 =20 =20 =20 =20 =20 =20 =20 =20 =20 ------------------------------------------------------------------------ No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.9.15 - Release Date: = 4/16/2005 ------------------------------------------------------------------------ >> Homepage: http://www.flyrotary.com/ >> Archive: = http://lancaironline.net/lists/flyrotary/List.html =20 =20 =20 -------------------------------------------------------------------------= ----- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.9.15 - Release Date: 4/16/2005 -------------------------------------------------------------------------= ----- >> Homepage: http://www.flyrotary.com/ >> Archive: http://lancaironline.net/lists/flyrotary/List.html ------=_NextPart_000_00B6_01C543F1.F9EDAE90 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
 
No Georges, no tools missing - had not done any work on the engine = for a=20 number of flights.  Nothing of a "diamond" shape has come to mind = either=20 {:>). 
 
  Beware! the fact that a seal slot is worn will not keep you = from=20 having compression, if the seal is still being pressed against the rotor = housing.  So that is not  necessarily a good test of slot = wear -=20 the problem is slot wear changes the magnitude and  angle = of forces=20 mix acting on the apex seal.  If they get to a certain point, they = can=20 fracture the rather brittle apex seal.   
 
 I am fairly certain that the wear limits on the slots = specified by=20 Mazda are there for a good reason. If the seals are approx 1.91 mm wide = and the=20 bottom of the slots appear to be around 1.98 wide then the new seal in = the new=20 slot have a clearance of about 1.98 - 1.91 =3D 0.07 mm.  And as you = can see=20 from the specs taken from the Mazda workshop manual that is well within = the=20 standard (near the lower end).  To stay with the maximum Limit = spec=20 (0.15mm) the slot should be no wider than 1.91 + 0.15 =3D 2.06mm.  = So when=20 you have slots measuring 2.16 to 2.43 mm wide,  its clear to me=20 that they are WAY beyond the limit.  You of course can choose = to=20 accept that and perhaps for an auto I would as well - but not me - not = for an=20 aircraft use. 
 

Clearance of apex seal and rotor groove

  

Standard

0.0024 to 0.004 in (0.062 to 0.102mm)

Limit

0.006 in (0.15mm)

 
 Of course, apex = seals won't=20 cause the engine to smoke, bad oil seal/rings will.  But,  I = assume=20 you mentioned that as an indication of the good condition the = engine was=20 in.  It may be running well now,  but the question is  = how much=20 longer would it have run.  In auto use perhaps for quite a spell - = in=20 aircraft use perhaps less, who knows for certain?
 
I clearly do not have decades of rotary engine experience, but I do = believe=20 that the engine manufacture probably has good reason for limits in=20 specifications.  If you are near, but within the limits = you=20 should be OK, but when you get way past the limit then you are on = borrowed time=20 as they say.  Just my opinion of course.
 
 
One of the reason I am going with Tracy Crooks apex seals is to get = a much=20 stronger, non-brittle seal.  I saw a big man try to break one of = Tracy's=20 seals by pressing it against the corner of a table and using his weight = to break=20 the seal.  A normal stock seal you can break with your hands (use = gloves if=20 trying) but  after apply all his weight several times it began to = bend and=20 finally broke - but it was an impressive display of how strong those = seals=20 were.
 
Ed A
----- Original Message -----
From:=20 Echo=20 Lake Fishing Resort (Georges Boucher)
Sent: Monday, April 18, 2005 = 1:10=20 AM
Subject: [FlyRotary] Re: New = rotors, New=20 housings

 Hi! Ed
I took another 91 13b NA apart today, it had good = compression on a=20 gauge six good pops at the exhaust port when rotated by hand, = didn't=20 smoke & ran well . The slots were 2.26 to 2.43 wide, the = apex seals=20 worn concave by about0.15mm on each side. by the wear on the = eccentric=20 shaft bearings this engine had spent a lot of time at high revs. = I doubt=20 very much that your engine demise was called by seal clearances, = You are=20 not missing any tools by any chance?
Georges Boucher
 
-------Original=20 Message-------
 
From: Rotary motors in=20 aircraft
Date: = 04/17/05=20 12:35:17
To: Rotary motors in=20 aircraft
Subject: = [FlyRotary]=20 Re: New rotors, New housings
 
I do know that my worn slots measured 1.98 mm at the bottom = and=20 range from 2.16 to 2.26mm at the top - giving an out of vertical = of from=20 0.18 to 0.28 mm.  The specs say a maximum feeler gauge = between an=20 inserted apex seal and wall is given as 0.15mm, I could insert = an 0.18=20 mm feeler in some and an  0.15mm in all.   I = don't think=20 I would feel comfortable flying with a rotary in that shape = (anymore=20 {:>)).  Putting them in an auto is a different story - = if it=20 breaks - park on side of the road rather than strain the = eyeballs=20 looking for an airpatch.
 
Ed A
----- Original Message ----- =
From:=20 Echo Lake Fishing = Resort (Georges=20 Boucher)
To: Rotary motors in = aircraft=20
Sent: Sunday, April 17, = 2005 3:24=20 PM
Subject: [FlyRotary] Re: = New=20 rotors, New housings

 Ken I screwed up on reporting the  rotor = slot=20 width, it should be 2.17 to 2.26mm not 2.017 to = 2.026mm
Georges 
-------Original=20 Message-------
 
From: Rotary motors = in=20 aircraft
Date: 04/17/05=20 07:51:53
To: = Rotary motors = in=20 aircraft
Subject:=20 [FlyRotary] Re: New rotors, New housings
 
 

--------------=20 Original message from keltro@att.net (Kelly = Troyer):=20 --------------

Georges,
    Are these numbers in reference to = the apex=20 seal slot taper from
the bottom of slot (2.017 mm) to the top of slot = (2.026 mm)=20 which
is a taper of (.009 mm) or about 3.54 thousands = here in=20 the 48 ??
--
Kelly Troyer =
Dyke=20 Delta/13B/RD1C/EC2




--------------=20 Original message from "Echo Lake Fishing Resort (Georges = Boucher)"=20 <echolakeresort@telus.net>: --------------

Correction, the readings were 2.017 to = 2.026mm
Georges  
 
-------Original=20 Message-------
 
From: Rotary = motors in=20 aircraft
Date:=20 04/16/05 19:05:31
To: Rotary = motors in=20 aircraft
Subject:=20 [FlyRotary] Re: New rotors, New housings
 
 Hi! Ken
Do you you cut on a taper, where does = your taper=20 start? or do you just skim 0.015" off each = side for a=20 total of 0.030". I just measured the two = rotors that=20 were in a "GOOD" running 92 13b NA & got a = reading=20 of 0.017 to 0.026mm, I guess they are = toast.
 
 Georges Boucher
-------Original=20 Message-------
 
  

 
 
=
 

No virus found in this outgoing message.
Checked by = AVG=20 Anti-Virus.
Version: 7.0.308 / Virus Database: 266.9.15 - = Release=20 Date: 4/16/2005

>>  Homepage: =20 http://www.flyrotary.com/
>>  Archive:   = http://lancaironline.net/lists/flyrotary/List.html
 

No virus found in this outgoing message.
Checked by AVG=20 Anti-Virus.
Version: 7.0.308 / Virus Database: 266.9.15 - Release = Date:=20 4/16/2005

>>  Homepage: =20 http://www.flyrotary.com/
>>  Archive:  =20 = http://lancaironline.net/lists/flyrotary/List.html
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