X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 17 Jan 2012 13:59:32 -0500 Message-ID: X-Original-Return-Path: Received: from snt0-omc3-s14.snt0.hotmail.com ([65.55.90.153] verified) by logan.com (CommuniGate Pro SMTP 5.4.3) with ESMTP id 5353830 for lml@lancaironline.net; Tue, 17 Jan 2012 13:37:16 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.55.90.153; envelope-from=gary21sn@hotmail.com Received: from SNT112-DS15 ([65.55.90.137]) by snt0-omc3-s14.snt0.hotmail.com with Microsoft SMTPSVC(6.0.3790.4675); Tue, 17 Jan 2012 10:36:39 -0800 X-Originating-IP: [24.216.249.79] X-Originating-Email: [gary21sn@hotmail.com] X-Original-Message-ID: X-Original-Return-Path: gary21sn@hotmail.com From: "Gary Edwards" X-Original-To: "Lancair Mailing List" References: Subject: Re: Ceramic exhaust coatings X-Original-Date: Tue, 17 Jan 2012 10:36:55 -0800 In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0297_01CCD503.EF157200" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 Seal-Send-Time: Tue, 17 Jan 2012 10:36:55 -0800 X-MimeOLE: Produced By MSN MimeOLE V10.20.0091.1100 X-OriginalArrivalTime: 17 Jan 2012 18:36:39.0088 (UTC) FILETIME=[F3290300:01CCD546] This is a multi-part message in MIME format. ------=_NextPart_000_0297_01CCD503.EF157200 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable ...But if it makes you feel good.... Nice rip Fred. So, all those racers out there (motorcycles, quads, drag cars, sand = rails, drag boats, snowmobiles, etc.) with heat coatings on top of their = pistons are only using it to "feel good"? On a side note, I know it sure keeps my chrome motorcycle pipes from = turning brown or blue. Oh, and they have not shown symptoms of failure = after years of use. Read below. ...Don't do it. It will droop off due to gravity having absolutely no = creep strength, and will drop in a heap in a few hours. And it will = rust to dust in a few cycles.... ...Mild steel has no capability in this operating regime. Why is it then that there are hundreds, no thousands, of experimentals = out there (several at this airport)with steel exhaust systems that have = been flying for years, decades, with no problems or symptoms that you = describe? Gary=20 =20 ----- Original Message -----=20 From: Frederick Moreno=20 To: lml@lancaironline.net=20 Sent: Tuesday, January 17, 2012 8:41 AM Subject: [LML] Fw: Re: Ceramic exhaust coatings . "But there hasn't been much posted on the subject of interior = heat coatings for the exhaust system." =20 Can't hurt, reduces the heat flow to the metal slightly, but = only slightly. Too thin and has too high a thermal conductivity to = help much. But if it makes you feel good. Leave the outside surface = alone and let it turn its natural black. When the exhaust manifold has = reached the end of its life due to thinning of walls extensive cracking, = or creep (see picture posted by Brent), replace it. Think of exhaust = manifolds like oil filters. Plan on regular replacement depending on = the operating regime. More demanding (such as turboappliction), shorter = replacement interval. =20 Don't even think about Inconel (very high temp alloy) exhaust = headers. Not worth it. =20 "I might go with a mild steel system if I were to do it again." Don't do it. It will droop off due to gravity having absolutely = no creep strength, and will drop in a heap in a few hours. And it will = rust to dust in a few cycles. That is why stainless steel is used - = because of its higher strength at elevated temperatures and because of = its corrosion resistance under the same conditions. Mild steel has no = capability in this operating regime.=20 Fred=20 =20 =20 ------=_NextPart_000_0297_01CCD503.EF157200 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
...But if it makes you feel good....
 
Nice rip Fred.
 
So, all those racers out there (motorcycles, quads, drag cars, sand = rails,=20 drag boats, snowmobiles, etc.) with heat coatings on top of their = pistons=20 are only using it to "feel good"?
 
On a side note, I know it sure keeps my chrome motorcycle pipes = from=20 turning brown or blue.  Oh, and they have not shown symptoms of = failure=20 after years of use.  Read below.
 
...Don't do it.  It will droop off due to = gravity having=20 absolutely no creep strength, and will drop in a heap in a few = hours.  And=20 it will rust to dust in a few cycles....
...Mild steel has no capability in this operating=20 regime.
 
Why is it then that there are hundreds, no thousands, of = experimentals out=20 there (several at this airport)with steel exhaust systems that have been = flying=20 for years, decades, with no problems or symptoms that you = describe?
 
Gary 
 
----- Original Message -----
From: Frederick Moreno =
Sent: Tuesday, January 17, 2012 = 8:41=20 AM
Subject: [LML] Fw: Re: Ceramic = exhaust=20 coatings

 
.
 
"But there hasn't been much posted on the subject of = interior heat=20 coatings for the exhaust system." 
 
Can't hurt, reduces the heat flow to the metal slightly, = but only=20 slightly.   Too thin and has too high a thermal = conductivity=20 to  help much.  But if it makes you feel good. =  Leave the=20 outside surface alone and let it turn its natural black.  = When the=20 exhaust manifold has reached the end of its life due to thinning = of=20 walls extensive cracking, or creep (see picture posted by = Brent),=20 replace it.  Think of exhaust manifolds like oil = filters. =20 Plan on regular replacement depending on the operating = regime. =20 More demanding (such as turboappliction), shorter replacement=20 interval. 
 
Don't even think about Inconel (very high temp alloy) = exhaust=20 headers.  Not worth it. 
 
"I might go with a mild steel system if I were to do it=20 again."
 
Don't do it.  It will droop off due to = gravity having=20 absolutely no creep strength, and will drop in a heap in a few=20 hours.  And it will rust to dust in a few cycles.  = That is why=20 stainless steel is used - because of its higher strength at = elevated=20 temperatures and because of its corrosion resistance under the = same=20 conditions.  Mild steel has no capability in this = operating=20 regime.
Fred
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