X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imr-db02.mx.aol.com ([205.188.91.96] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4228842 for flyrotary@lancaironline.net; Wed, 21 Apr 2010 02:44:28 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.188.91.96; envelope-from=WRJJRS@aol.com Received: from imo-ma01.mx.aol.com (imo-ma01.mx.aol.com [64.12.78.136]) by imr-db02.mx.aol.com (8.14.1/8.14.1) with ESMTP id o3L6hee9017410 for ; Wed, 21 Apr 2010 02:43:40 -0400 Received: from WRJJRS@aol.com by imo-ma01.mx.aol.com (mail_out_v42.9.) id q.e0f.25f2e03 (43849) for ; Wed, 21 Apr 2010 02:43:37 -0400 (EDT) Received: from magic-m18.mail.aol.com (magic-m18.mail.aol.com [172.21.136.206]) by cia-dc04.mx.aol.com (v128.3) with ESMTP id MAILCIADC046-ab494bce9e992c4; Wed, 21 Apr 2010 02:43:37 -0400 From: WRJJRS@aol.com Message-ID: <2a809.17737444.38fff899@aol.com> Date: Wed, 21 Apr 2010 02:43:37 EDT Subject: Re: [FlyRotary] Re: cooling for ground runs To: flyrotary@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_2a809.17737444.38fff899_boundary" X-Mailer: 9.0 SE for Windows sub 5046 X-AOL-ORIG-IP: 75.210.194.153 X-AOL-IP: 172.21.136.206 X-Spam-Flag:NO X-AOL-SENDER: WRJJRS@aol.com --part1_2a809.17737444.38fff899_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 4/20/2010 9:25:16 PM Pacific Daylight Time, shipchief@aol.com writes: I'm thinking an aluminum plate of 6061 could be cut, drilled, milled, then the wear faces "Nikasil" equivalent electroplated. Is that fairly straightforward if P Ported? Chief, Yes, that is a possible method. Do something for me. Look up the coefficient of linear expansion for aluminum. Then look up the coefficient of linear expansion for chrome (or Nickasil). You will find that the aluminum is about 10^-5 units per degree F. Chrome is about 10^-6 or 7 units per degree F. Every time the engine heats up the aluminum is trying to expand itself right past the coating. It work fairly well in a bore, and less well on a flat surface. That is why Mazda paid so much money to do detonation gun coatings on their all aluminum Le Mans engine. I checked on these coatings and they are just silly expensive. The raw coating was about 1000 dollars per FACE and then you need to lap it. In a car used for road racing Nickasil might hold up, but think about putting that car on a track with a 200 mile long straight-away. That is what our aircraft use is like. I am not one of the dumb car engines can take it guys, but there are differences and some of those differences make it tough to just use coatings. Not impossible, but expensive. Now if you could make an intermediate housing that was one pound heaver than aluminum but had none of the problems, while still being around 12-15 pounds lighter than the stocker, doesn't it sound like a good idea? Bill Jepson --part1_2a809.17737444.38fff899_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 4/20/2010 9:25:16 PM Pacific Daylight Time,=20 shipchief@aol.com writes:
I'm thinking an aluminum plate of 6061 could be cut, drilled, mille= d,=20 then the wear faces "Nikasil" equivalent electroplated.
Is that fairly straightforward if P Ported?=20
Chief,
Yes, that is a possible method. Do something for me. Look up the=20 coefficient of linear expansion for aluminum. Then look up the coefficient= of=20 linear expansion for chrome (or Nickasil). You will find that the aluminum= is=20 about 10^-5 units per degree F. Chrome is about 10^-6 or 7 units per degre= e F.=20 Every time the engine heats up the aluminum is trying to expand itself rig= ht=20 past the coating. It work fairly well in a bore, and less well on a flat= =20 surface. That is why Mazda paid so much money to do detonation gun coating= s on=20 their all aluminum Le Mans engine. I checked on these coatings and they ar= e just=20 silly expensive. The raw coating was about 1000 dollars per FACE and then= you=20 need to lap it. In a car used for road racing Nickasil might hold up, but= think=20 about putting that car on a track with a 200 mile long straight-away. That= is=20 what our aircraft use is like. I am not one of the dumb car engines can ta= ke it=20 guys, but there are differences and some of those differences make it toug= h to=20 just use coatings. Not impossible, but expensive. Now if you could make an= =20 intermediate housing that was one pound heaver than aluminum but had none= of the=20 problems, while still being around 12-15 pounds lighter than the stocker,= =20 doesn't it sound like a good idea?
Bill Jepson
 
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