Return-Path: Received: from mailout2.pacific.net.au ([61.8.0.85] verified) by logan.com (CommuniGate Pro SMTP 4.3c3) with ESMTP id 880678 for flyrotary@lancaironline.net; Sun, 17 Apr 2005 02:17:48 -0400 Received-SPF: none receiver=logan.com; client-ip=61.8.0.85; envelope-from=peon@pacific.net.au Received: from mailproxy1.pacific.net.au (mailproxy1.pacific.net.au [61.8.0.86]) by mailout2.pacific.net.au (8.12.3/8.12.3/Debian-7.1) with ESMTP id j3H6H1ml006280 for ; Sun, 17 Apr 2005 16:17:01 +1000 Received: from ar1 (ppp2E3D.dyn.pacific.net.au [61.8.46.61]) by mailproxy1.pacific.net.au (8.12.3/8.12.3/Debian-7.1) with SMTP id j3H6GuIn006721 for ; Sun, 17 Apr 2005 16:16:56 +1000 Message-ID: <006101c54314$0fe3c740$3d2e083d@ar1> From: "Leon" To: "Rotary motors in aircraft" References: Subject: Apex Seal Groove Wear and Air Filters was Re: [FlyRotary] Re: New rotors, New housings Date: Sun, 17 Apr 2005 16:09:48 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_005E_01C54367.E0C02B30" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 This is a multi-part message in MIME format. ------=_NextPart_000_005E_01C54367.E0C02B30 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [FlyRotary] New rotors, New housingsHi Guys, Just need to clarify something that I have been discussing off list with = Ed. I don't THINK (but I'm not really sure) that his apex seal = collapsed and did the damage. The grooves are not badly worn enough, = nor are the seals sufficiently thin enough to turn in the grooves. Apex = seals don't normally break unless clouted by some obdurate object, and = we can't blame insane RPM or detonation as the culprit either. So while = the jury remains out on it, I remain of the opinion that his engine = swallowed something solid in the shape of the diamond impressions left = in his rotor.=20 Further, I thought I'd offer a little diatribe/rant on "Ingestion of = Foreign Objects" based on 32+ years of observation and experience with = Wankel engines. As an aside, I cracked up when I read a "Japlish" = exhortation that was included in the instructions of a HKS turbo kit I = purchased back in the early '80s. It said: "Prease being careful not = to allow any alien into port" Prescient advice indeed! Now over the years, I have found that the major cause of apex seal = groove wear is ingestion of abrasive material. The air ALWAYS contains = a certain amount of fine dust, except just after a rain storm. Proof = of this is the patina of crud left by said rain on any shiny surface, = most obvious on car duco. Here in Oz, we often get thick orange/brown = dust deposits from dust storms originating out in the desert hundreds of = miles west of the city on the other side of the Great Dividing Range. Now that very same dust, invisible though it may be, will act as a = fine lapping paste: if allowed into the engine, will, depending on the = concentration, sooner or later eventually chop out the apex seal = grooves, and the corner seal grooves. It will accumulate in the = grooves and the lapping action gets worse over time as the paste gets = thicker. Ed has told me that there is some construction work going on near his = hangar, and his aircaft is often covered with a film of dust. That = dust will also be all over the tarmac, taxiways, on the grass verges, = and in the air itself. If you are following another aircraft, you are = GUARANTEED to cop a lung full of fine dust, whether you can see it or = not. It stands to reason, seeing that any engine is just an air pump, = that it will act as a very efficient vacuum cleaner. Which gents, is why you should always supply your engine with nothing = but clean filtered air AND fuel. Most people wouldn't THINK about = running a fuel system without a fuel filter and a water trap. Additionally, a decent filter will also stop the rocks and pebbles, = and grains of sand that can get thrown up by the prop wash of the = preceeding aircraft, as well as the almost ubiquitous fine dust. = Wankel engines in particular are not very tolerant of being fed a meal = of anything solid. One small pebble, or a decent sized grain of quartz = sand or bluestone is sufficient to take out an apex seal. (And please = dont' tell me it can't happen as I've seen the results with my own eyes = on more than one occasion). I realise that there will be a bunch of people on this list who feel = air filters are un-necessary, but we can all become the victims and = prisoners of our own (often false) belief systems, no matter how = passionately and sincerely they are held. (I've no need to remind you = that there once was a bloke who said that EWPs COULDN'T cool a rotary). = So even if you do fly off water, you still can be exposed to the = products of dust storms from other parts of the country, or volcanic = ash (both often invisible - ask the guys in the BA 747 some years ago!). As a corollary, on many occasions, I have pulled down engines that = have had up to 550,000 kms on them (mainly 12A RX7 engines). Those that = have had regular servicing (regular oil and [air oil, & fuel] filter = changes) invariably have pristine rotors, that show little or = negiglible apex seal groove wear. OTOH, I have seen engine "chop out" = in as little as six months when run with a faulty air cleaner, and run = in dusty environments. Two things are important to prevent groove wear. Proper lubrication - = if the surfaces don't touch, they cannot wear - and elimination of = abrasive particles - which, when mixed with lubricant, acts as a VERY = efficient lapping compound.. Further, everyone should be scrupulously paranoid about loose objects = getting into the inlet tract. In the past 32+ years, I've seen the sad = results of just about everything being ingested - nuts, bolts, studs, = spring & flat washers, carby check balls, paper clips, lock wire = off-cuts, bits of cardboard, plastic, alloy trimmings, metal filings = and turnings etc, as well as sand, pebbles, and small rocks. NOTHING = good has EVER come of feeding a Wankel with any of this sort of = detritus. So please be extremely paranoid about inlet tract cleanliness = after working on it. While I'm on this topic, I should also exhort you to treat the exhaust = system with the same degree of cleanliness. Untill the engine actually = fires, it doesn't really know that the exhaust port is an egress = apeture. I've have seen stuff sucked up out of exhausts (particulalry = weld spatter, and even pieces of rag used to prevent stuff falling INTO = the exhaust and inadvertently left there!). =20 So that's my additional palm full of Roubles for today. Cheers, Leon ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Sunday, April 17, 2005 11:54 AM Subject: [FlyRotary] Re: New rotors, New housings Hi Ken, I really, really have no interest in running for your title, believe = me! {:>). I am inclined to agree that milling out the slot may indeed = take you pass some metal hardening that lessens the wear. While I must = admit that I am still a bit skeptical about the dust doing it to me in = 150 hours, I think the rotors had been run hard when I got them but just = didn't know what to check for. But, in any case I am going to add a = filter figuring it probably won't hurt. Besides, If I didn't add a = filter and something happened again, I'd never hear the end of it from = my friend, Leon. New rotors and housing are ordered. I figured depending on how Jerry = Hey and his PP project turns out, I might use them to practice cutting = PP port and then turn two of my good NA housings into PP housings - down = the road. Ed ----- Original Message -----=20 From: Ken Welter=20 To: Rotary motors in aircraft=20 Sent: Saturday, April 16, 2005 4:40 PM Subject: [FlyRotary] Re: New rotors, New housings I would look into getting 85-85 GSELE rotors with the 3 mm seals, = you would also need the weights to match them, then machine out your = rotors for a spare engine, you may need one to bale you out in the = future, if you keep this up you may knock me off the seat as president = of the dead stick club. I am now running rotors machined out to 3 mm seals and at about = 400 hrs on them I can tell by checking through the exhaust port that the = seal grooves are getting V'ed out and getting sloppy so I am now putting = another engine together, on this one the rotors are in prime shape so I = think I will run Tracy's 2mm seals. Also I think that the groves may be hardened and by machining the = groves out makes them softer as they shouldn't have worn out in only 400 = hrs. Ken Well, the decision has been made. Thanks in part to the wife's = continued interest in my warm body on cold winter nights, the decision = has been made to purchase new rotors and rotor housings. $$ but = apparently I am worth it {:>) I looked into milling out the slots to 3mm and that would have = been the cheaper approach - but cheap approach is probably partly = responsible for me being in this situation - so going to try a different = approach this time. Besides leery of using a rotor which clearly has = been subjected to sufficient loads to scrape metal off its surface and = peen over apex slot. In the process of getting quotes. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com ------=_NextPart_000_005E_01C54367.E0C02B30 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: [FlyRotary] New rotors, New housings
Hi Guys,
 
Just need to clarify something that I = have been=20 discussing off list with Ed.   I don't THINK (but I'm not = really sure)=20 that his apex seal collapsed and did the damage. The grooves are = not badly=20 worn enough,  nor are the seals sufficiently thin enough to turn in = the=20 grooves.  Apex seals don't normally break unless clouted by some = obdurate=20 object,  and we can't blame insane RPM or detonation as the culprit = either.  So while the jury remains out on it,  I = remain of=20 the opinion that his engine swallowed something solid in the shape of = the=20 diamond impressions left in his rotor. 
 
Further,  I thought I'd offer a = little=20 diatribe/rant on "Ingestion of Foreign Objects" based on 32+ years of=20 observation and experience with Wankel engines.  As an aside,  = I=20 cracked up when I read a "Japlish" exhortation that was included in the=20 instructions of a HKS turbo kit I purchased back in the early = '80s.  It=20 said:  "Prease being careful not to allow any alien into = port" =20 Prescient advice indeed!
 
Now over the years,  I have found = that the=20 major cause of apex seal groove wear is ingestion of abrasive = material. =20 The air ALWAYS contains a certain amount of fine dust,  except just = after a=20 rain storm.  Proof of this is the patina of crud left by said rain = on any=20 shiny surface,  most obvious on car duco.  Here in Oz,  = we often=20 get thick orange/brown dust deposits from dust storms originating out in = the=20 desert hundreds of miles west of the city on the other side of = the=20 Great Dividing Range.
 
Now that very same dust,  = invisible though it=20 may be,  will act as a fine lapping paste: if allowed into the = engine,  will,  depending on the = concentration,  sooner or=20 later eventually chop out the apex seal grooves,  and the corner = seal=20 grooves.  It will accumulate in the grooves and the lapping action = gets=20 worse over time as the paste gets thicker.
 
Ed has told me that there is = some construction=20 work going on near his hangar,  and his aircaft is often covered = with a=20 film of dust.  That dust will also be all over the tarmac, =20 taxiways,  on the grass verges, and in the air itself.  = If you=20 are following another aircraft,  you are GUARANTEED to cop a lung = full of=20 fine dust,  whether you can see it or not.  It stands to = reason, =20 seeing that any engine is just an air pump,  that it will act as a = very=20 efficient vacuum cleaner.
 
Which gents,  is why you should = always supply=20 your engine with nothing but clean filtered air AND fuel.  = Most people=20 wouldn't THINK about running a fuel system without a fuel filter and a = water=20 trap.
 
Additionally,  a decent filter = will also stop=20 the rocks and pebbles,  and grains of sand that can get thrown up = by the=20 prop wash of the preceeding aircraft,  as well as the almost=20 ubiquitous fine dust.  Wankel engines in particular are not = very=20 tolerant of being fed a meal of anything solid. One small = pebble,  or=20 a decent sized grain of quartz sand or bluestone is sufficient to take = out an=20 apex seal. (And please dont' tell me it can't happen as I've seen = the=20 results with my own eyes on more than one occasion).
 
 I realise that there will be a = bunch of=20 people on this list who feel air filters are un-necessary,  = but we can=20 all become the victims and prisoners of our own (often false) belief=20 systems,  no matter how passionately and sincerely they are = held. =20 (I've no need to remind you that there once was a bloke who said that = EWPs=20 COULDN'T cool a rotary). 
 
So even if you do fly off = water,  you=20 still can be exposed to the products of dust storms from other parts of = the=20 country,  or volcanic ash (both often invisible - ask the guys in = the BA=20 747 some years ago!).
 
As a corollary,  on many = occasions,  I=20 have pulled down engines that have had up to 550,000 kms on them (mainly = 12A RX7=20 engines).  Those that have had regular servicing (regular oil and = [air=20 oil,  & fuel] filter changes) invariably have pristine = rotors, =20 that show little or negiglible apex seal groove wear.  OTOH,  = I have=20 seen engine "chop out" in as little as six months when run with a faulty = air=20 cleaner,  and run in dusty environments.
 
Two things are important to prevent = groove=20 wear.  Proper lubrication - if the surfaces don't touch,  they = cannot=20 wear - and elimination of abrasive particles - which,  when mixed = with=20 lubricant,  acts as a VERY efficient lapping = compound..
 
Further,  everyone should be = scrupulously=20 paranoid about loose objects getting into the inlet tract.  In the = past 32+=20 years,  I've seen the sad results of just about everything = being=20 ingested - nuts,  bolts, studs, spring & flat=20 washers, carby check balls,  paper clips, lock wire off-cuts, = bits of=20 cardboard,  plastic,  alloy trimmings,  metal filings and = turnings etc,  as well as sand,  pebbles,  and small = rocks. =20 NOTHING good has EVER come of feeding a Wankel with any of this = sort of=20 detritus.  So please be extremely paranoid about inlet tract = cleanliness=20 after working on it.
 
While I'm on this topic,  I should = also exhort=20 you to treat the exhaust system with the same degree of = cleanliness. =20 Untill the engine actually fires, it doesn't really know that the = exhaust port=20 is an egress apeture.  I've have seen stuff sucked up out of = exhausts=20 (particulalry weld spatter,  and even pieces of rag used to prevent = stuff=20 falling INTO the exhaust and inadvertently left there!). =20
 
So that's my additional palm full = of Roubles=20 for today.
 
Cheers,
 
Leon
 
 
----- Original Message -----
From:=20 Ed=20 Anderson
Sent: Sunday, April 17, 2005 = 11:54=20 AM
Subject: [FlyRotary] Re: New = rotors, New=20 housings

Hi Ken,
 
I really, really have no interest in = running for=20 your title,  believe me! {:>).  I am inclined to = agree that=20 milling out the slot may indeed take you pass some metal hardening = that=20 lessens the wear.  While I must admit that I am still a bit = skeptical=20 about the dust doing it to me in 150 hours, I think the rotors had = been run=20 hard when I got them but just didn't know what to check for.  = But, in any=20 case I am going to add a filter figuring it probably won't=20 hurt.  Besides, If I didn't add a filter and something = happened=20 again, I'd never hear the end of it from my friend, Leon.
 
New rotors and housing are = ordered.  I=20 figured depending on how Jerry Hey and his PP project turns out, I = might use=20 them to practice cutting  PP port and then turn two of my good NA = housings into PP housings - down the road.
 
Ed
----- Original Message -----
From:=20 Ken=20 Welter
To: Rotary motors in = aircraft=20
Sent: Saturday, April 16, = 2005 4:40=20 PM
Subject: [FlyRotary] Re: New = rotors,=20 New housings

  I would look into getting 85-85 GSELE rotors with the 3 = mm=20 seals, you would also need the weights to match them, then machine = out your=20 rotors for a spare engine, you may need one to bale you out in the = future,=20 if you keep this up you may knock me off the seat as president of = the dead=20 stick club.
  I am now running rotors machined out to 3 mm seals and = at about=20 400 hrs on them I can tell by checking through the exhaust port that = the=20 seal grooves are getting V'ed out and getting sloppy so I am now = putting=20 another engine together, on this one the rotors are in prime shape = so I=20 think I will run Tracy's 2mm seals.
 Also I think that the groves may be hardened and by = machining the=20 groves out makes them softer as they shouldn't have worn out in only = 400=20 hrs.
  Ken



Well, the=20 decision has been made.  Thanks in part to the wife's = continued=20 interest in my warm body on  cold winter nights, the decision = has=20 been made to purchase new rotors and rotor housings.  $$ but=20 apparently I am worth it {:>)
 
I = looked into=20 milling out the slots to 3mm and that would have been the cheaper = approach=20 - but cheap approach is probably partly responsible for me being = in this=20 situation - so going to try a different approach this time.  = Besides=20 leery of using a rotor which clearly has been subjected to = sufficient=20 loads to scrape metal off its surface and peen over apex=20 slot.
 
In = the process of=20 getting quotes.
 
Ed
 
Ed=20 Anderson
Rv-6A N494BW Rotary Powered
Matthews, = NC
eanderson@carolina.rr.com

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