X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4231176 for flyrotary@lancaironline.net; Thu, 22 Apr 2010 17:05:46 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from sv1-1.aanet.com.au (mail.aanet.com.au [203.24.100.34]) by poplet2.per.eftel.com (Postfix) with ESMTP id 4D33F173941 for ; Fri, 23 Apr 2010 05:05:09 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by sv1-1.aanet.com.au (Postfix) with SMTP id 6B555BEC02D for ; Fri, 23 Apr 2010 05:05:08 +0800 (WST) Message-ID: <581FCE3A9B0B4AB0973C78B6C7DDEBB2@ownerf1fc517b8> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Lightweight rotary parts and engine mounts (was Cooling f... Date: Fri, 23 Apr 2010 07:05:08 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_001D_01CAE2B3.4EB8FCD0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 100422-1, 04/22/2010), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_001D_01CAE2B3.4EB8FCD0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Brian, This came up some time ago (maybe years ago), and it may have been Bill = who explained that a thinner flat pate would warp under the load of the = apex/ side seals. I believe Richard Sohn's concept to be the best = approach in regard to this and his cast iron plate is quite thick in = places to maintain it's shape, this is married to an aluminium plate = with O ring to separate the oil and water areas. I did the research on = this concept and found it wasn't quite as light as I would like - no = disrespect to Richards design. It wasn't until I heard about the chrome molly sandwich housing and the = weigh of it, was I convinced of the approach in regard to weight savings = and wear surface reliability. BTW the CM isn't sandwiched to any = aluminium - it's all CM. The question is how do you manufacture such an = item, not possible to weld on the inside, not to mention warping, so = furnace brazing in one operation is the answer. The brazing paste is = applied to the contact surfaces, clamped to hold it's shape and then = it's placed in an oven. How the hell they hold all those pieces in place = beats me , maybe some things have to be tacked in place prior to = assembly - I'm still pondering the process. What stops the thin CM from warping is all the little pieces(channel = walls) that guide the water flow, and the thicker centre section, which = are brazed to both sides of housing - as in the cast housing. Hope that helps. George (down under) Maybe having provisions for mounting on the front cover of the engine = would avoid conflicts with the exhaust system, and would lessen the = amount of mounting tubes/weight needed. I hate to sound like I'm pontificating here, but with all this talk of = aluminum side and middle housings with a nitrided wear surface, has = anyone thought about the minimum thickness of a steel wear plate to = avoid warping due to heating? The reason I ask is that I was thinking = that in order to have aluminum side housings, a sandwich of wear plates = with the rest of the side plate made from aluminum might work without = brazing the steel to the aluminum, if brazing is even possible. Instead = of brazing, O-rings like the water jacket o-rings might be incorporated. = Just a thought.=20 My RV-4 is 1090 lbs, heavier than I'd like. That's about 230 lbs = heavier than the Hatch/Beckham Powersport RV-4 at around 865 lbs, if I = recall correctly.=20 Brian trubee ------=_NextPart_000_001D_01CAE2B3.4EB8FCD0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Brian,
This came up some time ago (maybe years ago), and it may have been = Bill who=20 explained that a thinner flat pate would warp under the load of the = apex/ side=20 seals. I believe Richard Sohn's concept to be the best approach in = regard=20 to this and his cast iron plate is quite thick in places to = maintain=20 it's shape, this is married to an aluminium plate with O ring to = separate=20 the oil and water areas. I did the research on this concept and found it = wasn't=20 quite as light as I would like - no disrespect to Richards design.
 
It wasn't until I heard about the chrome molly sandwich housing and = the=20 weigh of it, was I convinced of the approach in regard to weight savings = and  wear surface reliability. BTW the CM isn't sandwiched to any = aluminium=20 - it's all CM. The question is how do you manufacture such an = item, not=20 possible to weld on the inside, not to mention warping, so furnace = brazing in=20 one operation is the answer. The brazing paste is applied to the contact = surfaces, clamped to hold it's shape and then it's placed in an = oven. How=20 the hell they hold all those pieces in place beats me , maybe = some=20 things have to be tacked in place prior to assembly - I'm still = pondering the=20 process.
What stops the thin CM from warping is all the little = pieces(channel=20 walls) that guide the water flow, and the thicker centre = section,=20 which are brazed to both sides of housing - as in the cast = housing.
Hope that helps.
George (down under)
Maybe having provisions for mounting on the front cover of the = engine=20 would avoid conflicts with the exhaust system, and would lessen the = amount of=20 mounting tubes/weight needed.
 
I hate to sound like I'm pontificating here, but with all this = talk of=20 aluminum side and middle housings with a  nitrided wear surface, = has=20 anyone thought about the minimum thickness of a steel wear plate to = avoid=20 warping due to heating? The reason I ask is that I was thinking that = in order=20 to have aluminum side housings, a sandwich of wear plates with the = rest of the=20 side plate made from aluminum might work without brazing the steel to = the=20 aluminum, if brazing is even possible. Instead of brazing, O-rings = like the=20 water jacket o-rings might be incorporated.  Just a thought. =
 
My RV-4 is 1090 lbs, heavier than I'd like. That's about 230 lbs = heavier=20 than the Hatch/Beckham Powersport RV-4 at around 865 lbs, if I recall=20 correctly.
 
Brian trubee
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