Return-Path: Received: from [24.25.9.103] (HELO ms-smtp-04-eri0.southeast.rr.com) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 572018 for flyrotary@lancaironline.net; Sat, 18 Dec 2004 08:23:13 -0500 Received-SPF: none receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-069-132-109-019.carolina.rr.com [69.132.109.19]) by ms-smtp-04-eri0.southeast.rr.com (8.12.10/8.12.7) with SMTP id iBIDMcCi022160 for ; Sat, 18 Dec 2004 08:22:39 -0500 (EST) Message-ID: <004101c4e504$5eaa5e70$2502a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Great to hear: was [FlyRotary] I'm better now Date: Sat, 18 Dec 2004 08:20:39 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003E_01C4E4DA.7561E590" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_003E_01C4E4DA.7561E590 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageRusty, glad to hear you have reconsidered, especially given the = amount of effort and how close (I think) to working out all the bugs. Having experienced several similar heart thumping, cushion gripping = events myself, I understand what you are going though. After all we are = putting ourselves at some degree of risk. However, I personally = consider the most dangerous part of each flight the 10 mile drive to the = airpatch on a narrow two lane road with everything from very senior = citizens to huge dump trucks passing me at a closure rate of 90 mph two = feet or so away. Think about it! Regarding the core. I think there are some significant difference = between the pressures and impulses encounter in the coolant system and = the oil system. For one the oil pump is a positive displacement pump = meaning that it is going to put out 156 psi (dropping to 80 psi by oil = controller activates) in rapid pulsation - regardless of what resistance = it encounters. The coolant pump on the other hand is a centrifugal = type pump, it does not have the high peak pulsation of the lobed oil = pump (smoother flow), plus if it encounters flow resistance, it simply = slows down the flow (head pressure increases) or it causes the pump to = cavitate. Also we have a difference in stress between a 80-100 psi = pulsating operating pressure and a 5-15 psi operating pressure in the = cores. I suspect the difference in viscosity is also a factor as the = cross channels are something on the order of 1/8-3/16 sq inches each. I = would imagine that cold 40-50 weigh oil encounters considerable = resistance to flow in these channels. Got to cause more stress on the = cores than water at least on startup before the oil has warmed up.. Now I am not a pump expert (nor any other kind - even on TV) but I = believe there are these significant differences between the stresses = encounter in the two different core applications. Besides, the core has = been used by numerous folks for coolant without problems and if mounted = correctly and with consideration of stresses on fittings I believe you = will do just fine in that application. However, if your confidence about using cores is somewhat understandably = shakened, then by all means have custom radiators built - worth it for = you peace of mind and still a small cost compared to your total = investment in the project. =20 Whatever you do don't sell it, but if you do sell it - don't sell it to = Ken Powers, he has more than enough unfinished projects {:>) Ed Anderson ------=_NextPart_000_003E_01C4E4DA.7561E590 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Rusty, glad to hear you have = reconsidered,=20 especially given the amount of effort and how close (I think) to working = out all=20 the bugs.
 
Having experienced = several similar =20  heart thumping, cushion gripping events myself, I understand what = you are=20 going though.  After all we are putting ourselves at some degree of = risk.  However, I personally consider the most dangerous part of = each=20 flight the 10 mile drive to the airpatch on a narrow two lane road with=20 everything from very senior citizens to huge dump trucks passing me at a = closure=20 rate of 90 mph two feet or so away.  Think about it!
 
Regarding the core.  I think there = are some=20 significant difference between the pressures and impulses encounter in = the=20 coolant system and the oil system.  For one the oil pump is a = positive=20 displacement pump meaning that it is going to put out 156 psi (dropping = to 80=20 psi by oil controller activates) in rapid pulsation - regardless of what = resistance it encounters.    The coolant pump on the = other hand=20 is a centrifugal type pump, it does not have the high peak pulsation of = the=20 lobed oil pump (smoother flow), plus if it encounters flow resistance, = it simply=20 slows down the flow (head pressure increases)  or it causes the = pump to=20 cavitate.  Also we have a difference in stress between a 80-100 psi = pulsating operating pressure and a 5-15 psi operating pressure in the = cores. I=20 suspect the difference in viscosity is also a factor as the cross = channels are=20 something on the order of 1/8-3/16 sq inches each.  I would imagine = that=20 cold 40-50 weigh oil encounters considerable resistance to flow in these = channels.  Got to cause more stress on the cores than = water at=20 least on startup before the oil has warmed up..
 
Now  I am not a pump expert (nor = any other=20 kind - even on TV) but I believe there are these significant differences = between=20 the stresses encounter in the two different core=20 applications. Besides, the core = has been=20 used by numerous folks for coolant without problems and if mounted = correctly and=20 with consideration of stresses on fittings I believe you will do just = fine in=20 that application.
 
However, if your confidence about using = cores is=20 somewhat understandably shakened, then by all means have custom = radiators built=20 - worth it for you peace of mind and still a small cost compared to=20 your total investment in the project. 
 
Whatever you do don't sell it, but if = you do sell=20 it - don't sell it to Ken Powers, he has more than enough unfinished = projects=20 {:>)
 
Ed Anderson
 
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