X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail.lincsatmail.com ([207.179.143.254] verified) by logan.com (CommuniGate Pro SMTP 5.0.8) with ESMTP id 986347 for flyrotary@lancaironline.net; Wed, 15 Feb 2006 15:41:51 -0500 Received-SPF: neutral receiver=logan.com; client-ip=207.179.143.254; envelope-from=echolakeresort@telus.net Received: from echolake-cc8a26 ([204.101.233.220]) (authenticated bits=0) by mail.lincsatmail.com (8.12.10/8.12.10) with ESMTP id k1FKepDC032414 for ; Wed, 15 Feb 2006 16:40:55 -0400 MIME-Version: 1.0 Message-Id: <43F391CD.000001.03248@ECHOLAKE-CC8A26> Date: Wed, 15 Feb 2006 12:40:45 -0800 (Pacific Standard Time) Content-Type: Multipart/Alternative; boundary="------------Boundary-00=_XFXQQL80000000000000" X-Mailer: IncrediMail (4502089) From: "Echo Lake Fishing Resort (Georges Boucher)" References: To: "Rotary motors in aircraft" Subject: Re: [FlyRotary] Re: Need for air filters X-FID: FLAVOR00-NONE-0000-0000-000000000000 X-Priority: 3 --------------Boundary-00=_XFXQQL80000000000000 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Well said Thomas. I'm with you on filters.=0D Georges B. =0D =0D -------Original Message-------=0D =0D From: rijakits=0D Date: 02/15/06 10:51:52=0D To: Rotary motors in aircraft=0D Subject: [FlyRotary] Re: Need for air filters=0D =0D Al,=0D =0D It is not the percentage of time you spend in (possible) dusty conditions versus clear, but about the split-second your istallation ingests the sma= ll piece that will wedge between the seals and the housing and kill the engi= ne in short order ( ..... though it won't throw a rod or valve .)=0D I think it was recently mentioned, that this is one of the few things whe= re the rotary is less forgiving than a piston - A piston might pop the FO around for a while and then spit it out. In the Rotary you have a high chance to wedge ity on the first half rotation (centrifugal force will ur= ge the FO to the outside....)=0D =0D I flew most of my flying hours in front of an airfilter on a piston. Powe= r was never a question - the particular engine installation is over dimensioned, so there is always excess-power available.....=0D =0D remember that altitude is not always clean either: Volcanic ash clouds, desert dust/sand reaches very high!!=0D =0D FWIW,=0D =0D Thomas J.=0D 8500 hrs and counting....=0D =0D ----- Original Message ----- =0D From: Al Gietzen =0D To: Rotary motors in aircraft =0D Sent: Wednesday, February 15, 2006 12:05 PM=0D Subject: [FlyRotary] Need for air filters=0D =0D =0D Subject: [FlyRotary] Re: Engine failures, Rotary or otherwise=0D =0D To clarify the air filter issue. I seem to remember someone posting a pag= e from the mazda manual regarding apex seal tolerances after Ed's failure a= nd later confirmed the slot was out of spec. I remember the manual said to check the air filter. Mazda seems to think running without a filter or (dirty filter?) will cause rotor apex seal slots wear. Is this correct?=0D =0D Bobby=0D =0D I don=92t think there is any doubt that every =91terrestrial=92 vehicle n= eeds an air filter. They run on dust laden surfaces, and, at times, on unpaved surfaces which themselves are dust; resulting in the ingestion of a lot o= f abrasive material.=0D =0D The rational (at least mine) for not using a filter on an aircraft is tha= t, a) it spends little of its time on a surface, and then on one that is pav= ed a periodically blown off by other aircraft, and b) the amount of particulates above a few hundred feet (and certainly at a few thousand fe= et) is very low; probably similar to what goes through a filter in dusty conditions.=0D =0D If my flights averaged something like a couple of hours each, there is ab= out 15 minutes on a relatively clean surface for every 2 hours up in clean ai= r.=20 If the rpm in the air is 5500 and that on the surface is 1800, then the fraction of air volume used where there may be some fine particulates of concern is about 4%.=0D =0D So I=92m willing to accept that in exchange for keeping the ram air manif= old pressure increase of about 1.5=94 Hg that I can get when cruising close t= o 200 mph for the 2 hours that I=92m not on the surface. A compact filter is g= oing to eat most if not all that ram pressure. If you aren=92t concerned abou= t the pressure loss, or you can include a sufficiently large filter enclosure, = and not lose too much of the ram pressure in expansion, contraction and frict= ion losses; then it makes sense to include an air filter.=0D =0D I am definitely not advocating not using a filter. Just giving you my rational, however faulted, for going without one. (BTW, I do have a scre= en at the largest diameter in the intake duct to prevent anything bigger tha= n about 1/32=94 from getting through).=0D =0D FWIW,=0D =0D Al=0D =0D =0D =0D =0D =0D With all due respect; I don=92t disagree with what you=92re saying here, = but I do take offense at you calling Tracy, myself, and others =93idiots=94 bec= ause we have chosen to run without an air filter. My intake is in front of the p= rop and above the wing strake. Anyway, why climb on that issue? There has n= ot been a single aircraft incident that I am aware of that has resulted from not using an air filter. Let=92s pick an issue which has caused a failur= e.=0D =0D I won=92t argue that running without a filter may reduce the engine life;= and I may consider one later. And yes, the engine would eventually fail; eve= ry engine will =96 filter or no filter - if you run it long enough.=0D =0D Al (I guess it=92s past my bedtime)=0D =0D =0D =0D =0D Rusty, and Group,=0D I understand your comments Rusty, and think you are both right and wrong= =2E I believe it is easier, for most people, to be successful with a standard aircraft engine. I DO NOT believe this is because the Lyc, Conti, or whatever is inherently more reliable. I do believe that the ancillaries a= re better developed for "conventional" aircraft engines. =0D Because we [FlyRotary or ACRE] are rotary enthusiasts we hear about EVERY rotary problem. If we heard about every Lyc problem caused on a daily bas= is we might never fly spam again! I am not trying to offer so anecdote to soothe the rotary faithful, as all failures are just that, failures. I wo= uld remind everyone that ALL Lyc installs in certified aircraft now come with AIR FILTERS! =0D I'LL SAY THIS FLAT OUT, IF YOU DON'T RUN A FILTER YOU WILL HAVE A FAILURE= ! I don't care if your running a conventional aircraft engine or conversion. Running unfiltered is simple idiocy. =0D It should also be said that for Lycoming to be having crankshaft failures= , and a significant number of them to initiate an AD is not only sad but smacks of reckless disregard. So saying that the aircooled aircraft engin= e is super reliable is simply setting yourself up for a fall. If you look a= t the statistics most of the engine failures are "certified" engines simply because there are more of them! =0D ANY ENGINE properly maintained and not operated outside it's normal limit= s will work just fine thank you, provided it is not a deficient design to begin with. The rotary requires a GOOD water and oil cooling system. If y= ou aren't willing to work on that, stop now and don't hurt the reputation of the rest of us and go buy a Lycoming. The rewards for a GOOD installation are many but won't "just happen." As Tracy said you must go in with the knowledge of the needed systems or you will fail. If you do slipshod work= , Rotary or Lycoming, YOU WILL FAIL. Someone put the old saying on the site= ,=20 How do you eat an elephant?" "One bite at a time!" This is the proper way= of looking at the jobs needed to be successful. You MUST do all the jobs. (e= at every bite) And most importantly you must do all the jobs well. Safety wi= re everything even though it's a pain in the ass. If you can't do all the jo= bs yourself it's no crime. Get HELP! Buy the redrive from Tracy. Or buy fro= m Mistral, or buy them from Marcotte. Build your system up and test it on t= he ground. If you overheat your system on the ground don't assume it will be better in the air! (It might be, but also might not be!) Plan for an adequate sized radiator. That would be a MINIMUM of 2 cubic inches pre HP= , and that only if you have PERFECT ducting. (3 c.i. per HP would be a safe= r bet) Don't expect you are the miracle guy that can change physics for you= r own project. Rusty has brought up some good points in pointing out that = if you want to fly soonest buy conventional. Bernie, you can probably rebuil= d your system from all new parts for less than the cost of two Lyc cylinder= s. As an older guy facing family pressures I can understand how you might no= t want to though. This is no crime. Your needs are your own, though I would prefer to see you go back to the rotary and succeed. We all need to go in with our eyes open. When setting up race cars and motorcycles I would loo= k at every part from the stand point what will happen if this part breaks? = If the result would be a crash I would redesign the part until I was SURE it wouldn't break. If you don't think a part is adequate DON'T USE IT! Your responsibility is to find a part that IS good enough. Don't just hope tha= t everything will be OK. Work it out. Run your system enough to be sure of = it in the air. I hope everyone takes this in the spirit intended which is to have us all come home safe.=0D Bill Jepson=0D =20 --------------Boundary-00=_XFXQQL80000000000000 Content-Type: Text/HTML; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Well said Thomas. I'm with you on filters.
Georges B. 
 
-------Original Message-------
 
From: rijakits
Date: 02/15/06 10:= 51:52
Subject: [FlyRotar= y] Re: Need for air filters
 
Al,
 
It is not the percentage of time you spend in (po= ssible) dusty conditions versus clear, but about the split-second your is= tallation ingests the small piece that will wedge between the seals and t= he housing and kill the engine in short order ( ..... though it won't thr= ow a rod or valve .)
I think it was recently mentioned, that this is o= ne of the few things where the rotary is less forgiving than a piston - A= piston might pop the FO around for a while and then spit it out. In the = Rotary you have a high chance to wedge ity on the first half rotation (ce= ntrifugal force will urge the FO to the outside....)
 
I flew most of my flying hours in front of an air= filter on a piston. Power was never a question - the particular engine in= stallation is over dimensioned, so there is always excess-power available= =2E....
 
remember that altitude is not always clean either= : Volcanic ash clouds, desert dust/sand reaches very high!!
 
FWIW,
 
Thomas J.
8500 hrs and counting....
 
----- Original Message -----
<= B>From: Al Gietzen
Sent: Wednesday, February 15, 2006= 12:05 PM
Subject: [FlyRotary] Need for air = filters

Subject: [FlyRotary] Re: Engine fa= ilures, Rotary or otherwise

 =

To clarify the air filter issue. I seem to remember someone= posting a page from the mazda manual regarding apex seal tolerances afte= r Ed's failure and later confirmed the slot was out of spec. I remem= ber the manual said to check the air filter. Mazda seems to think running= without a filter or (dirty filter?) will cause rotor apex seal slots wea= r.  Is this correct?

 =

Bobby

 

I don=92t think= there is any doubt that every =91terrestrial=92 vehicle needs an air fil= ter.  They run on dust laden surfaces, and, at times, on unpaved sur= faces which themselves are dust; resulting in the ingestion of a lot of a= brasive material.

&= nbsp;

The rational (a= t least mine) for not using a filter on an aircraft is that, a) it spends= little of its time on a surface, and then on one that is paved a periodi= cally blown off by other aircraft, and b) the amount of particulates abov= e a few hundred feet (and certainly at a few thousand feet) is very low; = probably similar to what goes through a filter in dusty conditions.

&= nbsp;

If my flights a= veraged something like a couple of hours each, there is about 15 minutes = on a relatively clean surface for every 2 hours up in clean air.  If= the rpm in the air is 5500 and that on the surface is 1800, then the fra= ction of air volume used where there may be some fine particulates of con= cern is about 4%.

&= nbsp;

So I=92m willin= g to accept that in exchange for keeping the ram air manifold pressure in= crease of about 1.5=94 Hg that I can get when cruising close to 200 mph f= or the 2 hours that I=92m not on the surface.  A compact filter is g= oing to eat most if not all that ram pressure.  If you aren=92t conc= erned about the pressure loss, or you can include a sufficiently large fi= lter enclosure, and not lose too much of the ram pressure in expansion, c= ontraction and friction losses; then it makes sense to include an air fil= ter.

&= nbsp;

I am definitely= not advocating not using a filter.  Just giving you my rational, ho= wever faulted, for going without one.  (BTW, I do have a screen at t= he largest diameter in the intake duct to prevent anything bigger than ab= out 1/32=94 from getting through).

&= nbsp;

FWIW,

&= nbsp;

Al

&= nbsp;

&= nbsp;

&= nbsp;

&= nbsp;

 

With all due respect; I don=92t disagree with what you=92= re saying here, but I do take offense at you calling Tracy, myself, and o= thers =93idiots=94 because we have chosen to run without an air filter.&n= bsp; My intake is in front of the prop and above the wing strake.  A= nyway, why climb on that issue?  There has not been a single aircraf= t incident that I am aware of that has resulted from not using an air fil= ter.  Let=92s pick an issue which has caused a failure.

 

I won=92t argue that running without a filter may reduce = the engine life; and I may consider one later.  And yes, the engine = would eventually fail; every engine will =96 filter or no filter - if you= run it long enough.

 

Al (I guess it=92s past my bedtime)

 

 

 

 

Rusty, and Group,

 I understand your comments Rusty, and think you are b= oth right and wrong. I believe it is easier, for most people, to be succe= ssful with a standard aircraft engine. I DO NOT believe this is because t= he Lyc, Conti, or whatever is inherently more reliable. I do believe that= the ancillaries are better developed for "conventional" aircraft engines= =2E

Because we [FlyRotary or ACRE] are= rotary enthusiasts we hear about EVERY rotary problem. If we heard about= every Lyc problem caused on a daily basis we might never fly spam again!= I am not trying to offer so anecdote to soothe the rotary faithful, as a= ll failures are just that, failures. I would remind everyone that ALL Lyc= installs in certified aircraft now come with AIR FILTERS! =

I'LL SAY THIS FLAT OUT, IF YOU DON'T RUN A FILTER YOU WILL = HAVE A FAILURE! I don't care if your running a conventional aircraft engi= ne or conversion. Running unfiltered is simple idiocy.

=

It should also be said that for Lycoming to be having crank= shaft failures, and a significant number of them to initiate an AD i= s not only sad but smacks of reckless disregard. So saying that the airco= oled aircraft engine is super reliable is simply setting yourself up for = a fall. If you look at the statistics most of the engine failures are "ce= rtified" engines simply because there are more of them!

ANY ENGINE properly maintained and not operated outside it'= s normal limits will work just fine thank you, provided it is not a defic= ient design to begin with. The rotary requires a GOOD water and oil cooli= ng system. If you aren't willing to work on that, stop now and don't hurt= the reputation of the rest of us and go buy a Lycoming. The rewards for = a GOOD installation are many but won't "just happen." As Tracy said you must go in with the knowledge of the needed syste= ms or you will fail. If you do slipshod work, Rotary or Lycoming, YOU WIL= L FAIL. Someone put the old saying on the site, "How do you eat an elepha= nt?" "One bite at a time!" This is the proper way of looking at the jobs = needed to be successful. You MUST do all the jobs. (eat every bite) And m= ost importantly you must do all the jobs well. Safety wire everything eve= n though it's a pain in the ass. If you can't do all the jobs yourself it= 's no crime. Get HELP!  Buy the redrive from Tracy. Or buy from Mistral, or buy them from Marcotte. Build your syste= m up and test it on the ground. If you overheat your system on the ground= don't assume it will be better in the air! (It might be, but also might = not be!) Plan for an adequate sized radiator. That would be a MINIMUM of = 2 cubic inches pre HP, and that only if you have PERFECT ducting. (3 c.i.= per HP would be a safer bet) Don't expect you are the miracle guy that c= an change physics for your own project.  Rusty has brought up some g= ood points in pointing out that if you want to fly soonest buy convention= al. Bernie, you can probably rebuild your system from all new parts for l= ess than the cost of two Lyc cylinders. As an older guy facing family pre= ssures I can understand how you might not want to though. This is no crim= e. Your needs are your own, though I would prefer to see you go back to t= he rotary and succeed. We all need to go in with our eyes open. When sett= ing up race cars and motorcycles I would look at every part from the stan= d point what will happen if this part breaks? If the result would be a cr= ash I would redesign the part until I was SURE it wouldn't break. If you = don't think a part is adequate DON'T USE IT! Your responsibility is to fi= nd a part that IS good enough. Don't just hope that everything will be OK= =2E Work it out. Run your system enough to be sure of it in the air. = ;I hope everyone takes this in the spirit intended which is to have = us all come home safe.

Bill Jepson

 
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