X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 50 [XX] (51%) URL: contains host with port number (-49%) URL: weird port adjustment Return-Path: Received: from smtp104.rog.mail.re2.yahoo.com ([206.190.36.82] verified) by logan.com (CommuniGate Pro SMTP 5.1.8) with SMTP id 2021680 for flyrotary@lancaironline.net; Wed, 02 May 2007 12:15:50 -0400 Received-SPF: none receiver=logan.com; client-ip=206.190.36.82; envelope-from=jmosur@rogers.com Received: (qmail 22666 invoked from network); 2 May 2007 16:14:48 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=rogers.com; h=Received:X-YMail-OSG:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=gmW4H+k+pmIlyDQ6CMLIj7v7KMB3qZABYQWEYK6mjYjeEvTSdsad9c5MqOnMpeC9WiN+bdKcoqTvmjDs4Q4S0AgHmGbCatGPuz8c96rGFCxZubjPDNw0hJREynC+nuylAayTJEIu0BhsN4Lip3YBgru4DEF8vXGkuklgsOg9OpI= ; Received: from unknown (HELO MOSUR) (jmosur@rogers.com@99.245.24.79 with login) by smtp104.rog.mail.re2.yahoo.com with SMTP; 2 May 2007 16:14:47 -0000 X-YMail-OSG: SJLjhVkVM1mWeCN8h8rpMz85el.XDyl0qSdqaggvpRmsaQpAZOVoMvZ3XckKZ8Bnzg-- Message-ID: <001c01c78cd4$e983c1b0$6400a8c0@MOSUR> From: "J Mosur" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: oil coolers Date: Wed, 2 May 2007 12:14:07 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0019_01C78CB3.61FD3FD0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 This is a multi-part message in MIME format. ------=_NextPart_000_0019_01C78CB3.61FD3FD0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I tried a water oil cooler on my RV6 around 7 years ago , it was not = very efficient in warm weather, settled on the good old Mazda oil cooler = and never looked back. Jim Mosur ----- Original Message -----=20 From: lehanover@aol.com=20 To: Rotary motors in aircraft=20 Sent: Wednesday, May 02, 2007 11:31 AM Subject: [FlyRotary] Re: oil coolers Well, Like electricity, the higher the voltage between two locations the = more electrons will flow, just as in the BTUs flowing from hotter to = cooler. Add in that oil tends to form up around the cooling tubes in a = cooler and insulate the hotter oil from those tubes. Thus great lengths = to cause turbulance in the oil tubes to scrub cooler oil off of the = tubes and improve heat transfer.=20 In the case of transfer of heat to water vice air, then water wins the = race every time. So an oil to water exchanger can be very much smaller = than an oil to air exchanger of the same BTU capacity.=20 So transfering the oils heat into the coolant is far easyier than = removing it from the coolant into the air. So, coolant and oil temps will be very close to each other. You will = notice that oil temps in rotaries tend to track the throttle setting, = and are best kept below 180 degrees for good power. Best power will be = found well below 160 degrees of oil temp, but very difficult without a = very large water radiator. The oil temp is an indication of rotor face = temps, and higher temps mean lower cylinder filling, and thus lower = power output. It is difficult to over cool the coolant, as the engine run fine below = 160 degrees of coolant temp.=20 Other advantages include no scat tube to a cooler is required. Actual = location is not important. Smaller size than for the oil to air cooler. = And very good oil temp control, and thus more power. NASCAR uses them, but their coolant radiators are huge with 4 or 5 = rows of tubes and the cost of a used car. About 70% of the BTUs going into the engine escape as waste heat. Most = as exhaust gas temperature. The rest through the coolers, and into your = shoes. Lynn E. Hanover =20 =20 -----Original Message----- From: echristley@nc.rr.com To: flyrotary@lancaironline.net Sent: Wed, 2 May 2007 7:14 AM Subject: [FlyRotary] Re: oil coolers lehanover@aol.com wrote:=20 >=20 >=20 > There is only air cooling. There is nothing else. If you can dump = the excess heat through the water radiator,=20 >=20 > then its a great idea, and works just fine. Oil temps above 160 = degrees cost power. The cooler the better.=20 >=20 > You will need 1/3 more water cooling than you started with to make = it work. You cannot fool Mother Nature. >=20 =20 Question from the peanut gallery. I don't plan to use a oil/water = exchanger, but aren't they counterproductive?=20 =20 The efficiency of the cooling relies on deltaT. The best situation is = having the hottest coolant interfacing with the air, and it has always = been my understanding that the oil exits the engine hotter than the = water. Will an oil/water exchanger reduce the overall efficiency of the = system by allowing the exit air, on average, to leave with less BTUs?=20 =20 --=20 Homepage: http://www.flyrotary.com/=20 Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html=20 -------------------------------------------------------------------------= ----- AOL now offers free email to everyone. Find out more about what's free = from AOL at AOL.com. ------=_NextPart_000_0019_01C78CB3.61FD3FD0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I tried a water oil cooler on my RV6 = around 7 years=20 ago , it was not very efficient in warm weather, settled on the good old = Mazda=20 oil cooler and never looked back.
 
 
Jim Mosur
----- Original Message -----
From:=20 lehanover@aol.com
Sent: Wednesday, May 02, 2007 = 11:31=20 AM
Subject: [FlyRotary] Re: oil=20 coolers


Well,
Like electricity, the higher the voltage between two = locations=20 the more electrons will flow, just as in the BTUs flowing from hotter = to=20 cooler. Add in that oil tends to form up around the cooling tubes in a = cooler=20 and insulate the hotter oil from those tubes. Thus great lengths to = cause=20 turbulance in the oil tubes to scrub cooler oil off of the tubes and = improve=20 heat transfer.

In the case of transfer of heat to water vice = air, then=20 water wins the race every time. So an oil to water exchanger can be = very much=20 smaller than an oil to air exchanger of the same BTU capacity. =

So=20 transfering the oils heat into the coolant is far easyier than = removing it=20 from the coolant into the air.
So, coolant and oil temps will be = very close=20 to each other. You will notice that oil temps in rotaries tend to = track the=20 throttle setting,  and are best kept below 180 degrees for good = power.=20 Best power will be found well below 160 degrees of oil temp, but very=20 difficult without a very large water radiator. The oil temp is an = indication=20 of rotor face temps, and higher temps mean lower cylinder filling, and = thus=20 lower power output.

It is difficult to over cool the coolant, = as the=20 engine run fine below 160 degrees of coolant temp.

Other = advantages=20 include no scat tube to a cooler is required. Actual location is not=20 important. Smaller size than for the oil to air cooler. And very good = oil temp=20 control, and thus more power.

NASCAR uses them, but their = coolant=20 radiators are huge with 4 or 5 rows of tubes and the cost of a used=20 car.

About 70% of the BTUs going into the engine escape as = waste heat.=20 Most as exhaust gas temperature. The rest through the coolers, and = into your=20 shoes.

Lynn E. = Hanover
 
 
-----Original=20 Message-----
From: echristley@nc.rr.com
To:=20 flyrotary@lancaironline.net
Sent: Wed, 2 May 2007 7:14 = AM
Subject:=20 [FlyRotary] Re: oil coolers

lehanover@aol.com=20 wrote: 
> 
> 
> There is only air = cooling.=20 There is nothing else. If you can dump the excess heat through the = water=20 radiator, 
> 
> then its a great idea, and works = just=20 fine. Oil temps above 160 degrees cost power. The cooler the=20 better. 
> 
> You will need 1/3 more water = cooling than=20 you started with to make it work. You cannot fool Mother Nature.=20 > 
 
Question from the peanut gallery. I don't plan = to use=20 a oil/water exchanger, but aren't they=20 counterproductive? 
 
The efficiency of the cooling = relies on=20 deltaT. The best situation is having the hottest coolant interfacing = with the=20 air, and it has always been my understanding that the oil exits the = engine=20 hotter than the water. Will an oil/water exchanger reduce the overall=20 efficiency of the system by allowing the exit air, on average, to = leave with=20 less BTUs? 
 
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Homepage: http://www.flyrotary.com/ 
Archive and = UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.htm= l 
AOL now offers free email to everyone. Find out more about what's free = from=20 AOL at AOL.com.
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