Return-Path: <13brv3@bellsouth.net> Received: from imf25aec.mail.bellsouth.net ([205.152.59.73] verified) by logan.com (CommuniGate Pro SMTP 4.1.3) with ESMTP id 2566479 for flyrotary@lancaironline.net; Wed, 03 Sep 2003 19:14:25 -0400 Received: from rad ([68.212.14.21]) by imf25aec.mail.bellsouth.net (InterMail vM.5.01.05.27 201-253-122-126-127-20021220) with ESMTP id <20030903231425.LPXQ1843.imf25aec.mail.bellsouth.net@rad> for ; Wed, 3 Sep 2003 19:14:25 -0400 From: "Russell Duffy" <13brv3@bellsouth.net> To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: water flow (the quiz) Date: Wed, 3 Sep 2003 18:14:24 -0500 Message-ID: <008a01c37271$1dc4bf10$0201a8c0@rad> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_008B_01C37247.34EEB710" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 In-Reply-To: This is a multi-part message in MIME format. ------=_NextPart_000_008B_01C37247.34EEB710 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable The pressure differential driving the water from the engine block heater outlet to the rad inlet is the pressure drop from half way through the engine to the rad inlet. Although this is enough to cause some flow; it = is likely quite a bit less than the pressure drop across the rad. By = returning the heater flow downstream from the rad, you take advantage of the = larger pressure drop and get more flow through the heater. Or is this stuff = you already know, and I missed the point here? Yeah, I understand, but I don't see why Mazda did it the way they did on = the 1st gen heat exchangers. Maybe Bruce was mistaken. His wife just had a baby the night before, so maybe he wasn't thinking straight :-) One of the difficulties with the oil-water heat exchanger built into the radiator is that they are designed for piston engines where the heating = of the oil is more incidental; it is not one of the cooling fluids as it is = in the rotary, so the heat rejection capacity is significantly less.=20 Roger, that's why I had them install two. I knew it was the only chance = I had of making it work. For the record, they had never even considered installing two heat exchangers on a radiator before mine.=20 =20 When I get the proper oil temp sensor installed later this week, I'll = find out if the current arrangement is sufficient. From what I've heard, I = feel like it's probably very close, and it sure doesn't get much hotter than = it has been recently, so maybe I can make it work with some modification. = It will be nice when I can use some of those spare ports in my radiator = tanks to measure the water temps at various points. Unfortunately, my cockpit = is littered with temporary gauges already. When the EM-2 arrives (someone = has to keep whining about it ), I'll be able to use some of the current gauges for testing. =20 Cheers, Rusty =20 ------=_NextPart_000_008B_01C37247.34EEB710 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Message

The pressure differential driving the water from the = engine=20 block heater outlet to the rad inlet is the pressure drop from half way = through=20 the engine to the rad inlet.  Although this is enough to cause some = flow;=20 it is likely quite a bit less than the pressure drop across the = rad.  By=20 returning the heater flow downstream from the rad, you take advantage of = the=20 larger pressure drop and get more flow through the heater.  Or is = this=20 stuff you already know, and I missed the point here?

Yeah, I = understand, but=20 I don't see why Mazda did it the way they did on the 1st gen heat=20 exchangers.  Maybe Bruce was mistaken.  His wife just had a = baby the=20 night before, so maybe he wasn't thinking straight :-)

One of the difficulties with the oil-water heat exchanger built into = the=20 radiator is that they are designed for piston engines where the heating = of the=20 oil is more incidental; it is not one of the cooling fluids as it is in = the=20 rotary, so the heat rejection capacity is significantly = less. 

Roger, = that's why I had=20 them install two.  I knew it was the only chance I had of = making it=20 work.  For the record, they had never even considered = installing two=20 heat exchangers on a radiator before mine.
 
When I get the proper oil temp = sensor=20 installed later this week, I'll find out if the current arrangement is=20 sufficient.  From what I've heard, I feel like it's probably very = close,=20 and it sure doesn't get much hotter than it has been recently, = so maybe I=20 can make it work with some modification.  It will be nice = when I can use some of those spare ports in my radiator tanks to = measure=20 the water temps at various points.  Unfortunately, my cockpit is = littered=20 with temporary gauges already.  When the EM-2 arrives (someone = has to=20 keep whining about it <g>), I'll be able to use some of = the=20 current gauges for testing.
 
Cheers,
Rusty
 
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