Return-Path: Received: from [65.54.168.111] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.3c3) with ESMTP id 881954 for flyrotary@lancaironline.net; Mon, 18 Apr 2005 10:54:25 -0400 Received-SPF: pass receiver=logan.com; client-ip=65.54.168.111; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Mon, 18 Apr 2005 07:53:37 -0700 Message-ID: Received: from 4.174.4.106 by BAY3-DAV7.phx.gbl with DAV; Mon, 18 Apr 2005 14:53:37 +0000 X-Originating-IP: [4.174.4.106] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Air filters Date: Mon, 18 Apr 2005 10:53:34 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_01BD_01C54404.DDCD89C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0011.1703 Seal-Send-Time: Mon, 18 Apr 2005 10:53:34 -0400 X-OriginalArrivalTime: 18 Apr 2005 14:53:37.0855 (UTC) FILETIME=[671124F0:01C54426] This is a multi-part message in MIME format. ------=_NextPart_000_01BD_01C54404.DDCD89C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable You are properly paranoid about hardware ingestion Todd, I am equally = so. I missed where Leon warned about cardboard but that would surprise = me. I have used plastic steel (JB Weld, etc) in my intake systems = without any problems (being very careful about details, surface prep, = etc). On my test stand I am not so careful and the engine has ingested = small pieces of epoxy, JB weld and super-fill during test runs. No = guarantees of course, but that engine is still running fine.=20 Air filters are a good idea and I'd never argue against them but OTOH I = have never used them in the 1500+ hours of flying. My first engine went = 856 hours (only replaced so I could try a different port scheme) and had = no noticeable wear on rotor housings, barely measurable wear on side = housings, apex seals had about .012 total wear on height. This is one = of the many areas where details and pilot technique can make a night and = day difference. My air intakes have always been at the top of the cowl = (dirt & sand density are highest near the ground of course (a bottom = scoop without filter would be 'not good') and I am careful about the = dust conditions when I am forced to taxi with traffic (avoid when = possible). On the subject of ram air, it really is not much of a factor below 120 = mph and no factor at all on takeoff. It becomes significant at top = speed which is about 225 mph on my RV-4. Tracy (waiting for runway to emerge before departing for Colorado) This thread has gotten me thinking about things that make rotors stop. = So tonight I removed the an item of concern. There was a screw = inside my airbox (under the filter) holding it down onto it's proper = position. This was due to the shape of the intake hose trying to move it = a little. However the heat from the engine and turbo over the last 50+ = hours has made it sit perfectly without the screw to hold it and once = the top cowl is in position it is captured and cannot move. But more disconcerting is another mod. Many builders have done = this and that is the plastic steel (JB weld or Devcon) inside the = secondary intakes in the end plates. During my first build I was all = ready to perform this task when I had thoughts about a piece of plastic = weld breaking loose and going through a rotor, so I omitted it. On my = second rebuild (after detonation incident), I went ahead with it, = thinking that if anything like this was going to happen I'd likely have = heard about it and also thinking that the engine would likely just pass = it through without incident. Now after reading Leon's testimonials about = things as trivial as a bit of cardboard taking out a rotor, I'm again = thinking about this.=20 Plastic steel is incredibly tough, but when I need to remove some, = I use my acetylene torch to heat it and it will crumble away in chunks. = Now if the engine is properly cooled it should never get anywhere near = hot enough to compromise the strength of this stuff, would it? What = about on a loss of coolant or other overheat situation. Even if the = engine doesn't appear to be damaged from this, what about the plastic = steel?=20 I'm not being paranoid or anything here, but just asking questions = to promote thought about plastic steel. Don't get me wrong, I think it = is wonderful stuff. Todd ------=_NextPart_000_01BD_01C54404.DDCD89C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
You are properly paranoid about hardware ingestion Todd, I am = equally=20 so.  I missed where Leon warned about cardboard but that would = surprise=20 me.  I have used plastic steel (JB Weld, etc) in my intake systems = without=20 any problems (being very careful about details, surface prep, = etc).  On my=20 test stand I am not so careful and the engine has ingested small pieces = of=20 epoxy, JB weld and super-fill during test runs.  No guarantees = of=20 course, but that engine is still running fine. 
 
Air filters are a good idea and I'd never argue against them but = OTOH I=20 have never used them in the 1500+ hours of flying.  My first engine = went=20 856 hours (only replaced so I could try a different port scheme) and had = no noticeable wear on rotor housings, barely measurable wear on = side=20 housings, apex seals had about .012 total wear on height.   = This is=20 one of the many areas where details and pilot technique can make a night = and day=20 difference.  My air intakes have always been at the top of the cowl = (dirt=20 & sand density are highest near the ground of course (a bottom scoop = without=20 filter would be 'not good') and I am careful about the dust conditions = when I am=20 forced to taxi with traffic (avoid when possible).
 
On the subject of ram air, it really is not much of a factor below = 120 mph=20 and no factor at all on takeoff.   It becomes significant at top = speed=20 which is about 225 mph on my RV-4.
 
Tracy  (waiting for runway to emerge before = departing for=20 Colorado)

This=20 thread has gotten me thinking about things that make rotors stop.=20
    So tonight I removed the an item of = concern. There=20 was a screw inside my airbox (under the filter) holding it down = onto it's=20 proper position. This was due to the shape of the intake hose trying = to move=20 it a little. However the heat from the engine and turbo over the last = 50+=20 hours has made it sit perfectly without the screw to hold it and once = the top=20 cowl is in position it is captured and cannot = move.
    But more disconcerting is another mod. Many = builders have=20 done this and that is the plastic steel (JB weld or Devcon) inside the = secondary intakes in the end plates. During my first build I was = all=20 ready to perform this task when I had thoughts about a piece of = plastic weld=20 breaking loose and going through a rotor, so I omitted it. On my = second=20 rebuild (after detonation incident), I went ahead with it, thinking = that if=20 anything like this was going to happen I'd likely have heard about it = and also=20 thinking that the engine would likely just pass it through without = incident.=20 Now after reading Leon's testimonials about things as trivial as a bit = of=20 cardboard taking out a rotor, I'm again thinking about this.=20
    Plastic steel is incredibly tough, but when I = need to=20 remove some, I use my acetylene torch to heat it and it will crumble = away in=20 chunks. Now if the engine is properly cooled it should never get = anywhere near=20 hot enough to compromise the strength of this stuff, would it? = What about=20 on a loss of coolant or other overheat situation. Even if the engine = doesn't=20 appear to be damaged from this, what about the plastic steel?=20
    I'm not being paranoid or anything here, but = just asking=20 questions to promote thought about plastic steel. Don't get me wrong, = I think=20 it is wonderful stuff.
 
Todd
 
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