X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 12 Mar 2009 19:30:04 -0400 Message-ID: X-Original-Return-Path: Received: from betsy.gendns5.com ([65.254.38.234] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTPS id 3545172 for lml@lancaironline.net; Thu, 12 Mar 2009 11:10:54 -0400 Received-SPF: none receiver=logan.com; client-ip=65.254.38.234; envelope-from=paul@tbm700.com Received: from [97.104.178.107] (port=57572 helo=[192.168.1.124]) by betsy.gendns5.com with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.69) (envelope-from ) id 1LhmY2-0004mL-Ng for lml@lancaironline.net; Thu, 12 Mar 2009 11:10:16 -0400 X-Original-Message-Id: From: paul miller X-Original-To: "Lancair Mailing List" In-Reply-To: Content-Type: multipart/alternative; boundary=Apple-Mail-52-865374837 Mime-Version: 1.0 (Apple Message framework v930.3) Subject: Re: [LML] Re: oil cooling/Vernatherm X-Original-Date: Thu, 12 Mar 2009 11:10:12 -0400 References: X-Mailer: Apple Mail (2.930.3) X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - betsy.gendns5.com X-AntiAbuse: Original Domain - lancaironline.net X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - tbm700.com --Apple-Mail-52-865374837 Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit You might want to read this thread http://www.vansairforce.com/community/showthread.php?t=32763 It describes the vernatherm operation. It causes the bypass to the engine to close and forces oil through the cooler. They describe a test moving it 1/4 inch. If it does not close off the bypass completely then you may not be getting full flow through the cooler. Paul N357V On 12-Mar-09, at 10:34 AM, randy snarr wrote: > > Scott, > > I was thinking the same thing and am making plans to "redo" my oil > cooler to cowl connection and make it nice and smooth. That will > happen after I verify the vernatherm is doing what is supposed to... > I pulled out the vernatherm the other day and put it in boiling > water to see what it would do. > I admit I really do not understand how it works but the spring > loaded end got about 1/8" longer when going from room temp to 212 F. > Does that mean it is working? > If anyone knows if this is good or bad, please pipe in... > > Thanks for the feedback! > Randy Snarr > --- On Tue, 3/10/09, Sky2high@aol.com wrote: > > From: Sky2high@aol.com > Subject: [LML] Re: oil cooling > To: lml@lancaironline.net > Date: Tuesday, March 10, 2009, 8:36 PM > > Randy, > > My large sharp edged NACA duct is poorly placed on the left rearward > side of cowling. It enters a short flexible 3" smooth rubber sleeve > (plumber's sleeve) and then to a plenum above the small SW oil > cooler mounted to the fire wall. The bottom is open to the lower > cowl. I climb at about 135 KIAS and see cylinders occasional reach > 400 degrees on a hot day while the oil stays at 180. In cruise in > 30-40F temps, I must at least partially close the door between the > NACA and the cooler. Recently, in 10C temps, I had to completely > close the door to keep the oil temps about 180. In the pattern at > 100 KIAS I will see the oil go 190F or even 200F on hot days because > of lack of air thru the cooler. > > It wasn't always that way. > > When I had high oil temps, I tried a special cooler air exit to > assist, no help. > Another was to try exiting thru shark gills on the side of the cowl, > no help. > I temporarily attached a scoop to force more air in the duct, no help. > > I finally discovered that the air was backed up in the NACA duct > plenum (or chamber), thus cutting off air flow. I used Micro to > smoothly shape the chamber, thus directing the air into its 3" > outlet (no more dead corners) with the results detailed above. > > Good Luck, > > Scott Krueger AKA Grayhawk > Lancair N92EX IO320 SB 89/96 > Aurora, IL (KARR) > > In a message dated 3/9/2009 12:41:32 P.M. Central Daylight Time, marv@lancair.net > writes: > Posted for randy snarr : > > All, > Thanks for the good suggestions on the oil cooler. > I flew again today and my oil temps are at 208 F flying in 35 f air. > They will be 215 or 220 this summer. > I will try a few solutions that do not need to cut the cowl. I will > most > likely make a duct to carry the exhaust air from the oil cooler down > to the > lower aft part of the cowl. I have also heard that the aft vertical > edge of > the naca opening should be shaped like an air foil. Mine is flat and > fairly > sharp. The easiest way to test will to be construct a piece to give > it a > little airfoil made from balsa or foam taped in place and flight > tested. If > that does not work, I will make a duct from the cooler to the low > pressure > area on the bottom of the cowl and lastly would be a small lip on > the bottom > of the cowl aft. > every producton airplane I have seen with an opening on the bottom > of the > cowl has 45 deg lip to create a low pressure area. I should have > done that > before I painted.... > > > I will post my findings when I get them. > > Randy Snarr > N694RS > > > > -- > > SFor archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html > > > A Good Credit Score is 700 or Above. See yours in just 2 easy steps! > --Apple-Mail-52-865374837 Content-Type: text/html; charset=US-ASCII Content-Transfer-Encoding: quoted-printable You might want to read this = thread


It describes the vernatherm operation.  It causes = the bypass to the engine to close and forces oil through the cooler. =  They describe a test moving it 1/4 inch.  If it does not = close off the bypass completely then you may not be getting full flow = through the = cooler.

Paul
N357V

<= div>On 12-Mar-09, at 10:34 AM, randy snarr wrote:


Scott,

I was thinking = the same thing and am making plans to "redo" my oil cooler to cowl = connection and make it nice and smooth. That will happen after I verify = the vernatherm is doing what is supposed to...
I pulled out the = vernatherm the other day and put it in boiling water to see what it = would do.
I admit I really do not understand how it works but the = spring loaded end got about 1/8" longer when going from room temp to 212 = F.
Does that mean it is working?
If anyone knows if this is good = or bad, please pipe in...

Thanks for the feedback!
Randy = Snarr
--- On Tue, 3/10/09, Sky2high@aol.com <Sky2high@aol.com> = wrote:

From: Sky2high@aol.com <Sky2high@aol.com>
Subject: = [LML] Re: oil cooling
To: lml@lancaironline.net
Date: = Tuesday, March 10, 2009, 8:36 PM

=
Randy,
 
=
My large sharp edged NACA duct is poorly placed on = the left rearward side of cowling.  It enters a short flexible = 3" smooth rubber sleeve (plumber's sleeve) and then to a plenum above = the small SW oil cooler mounted to the fire wall.  The bottom is = open to the lower cowl.  I climb at about 135 KIAS and see = cylinders occasional reach 400 degrees on a hot day while the oil stays = at 180.  In cruise in 30-40F temps, I must at least partially close = the door between the NACA and the cooler.  Recently, in 10C temps, = I had to completely close the door to keep the oil temps about 180. In = the pattern at 100 KIAS I will see the oil go 190F or even 200F on hot = days because of lack of air thru the cooler. 
=
 
It wasn't always that = way.
 
When I = had high oil temps, I tried a special cooler air exit to assist, no = help.
Another was to try exiting thru shark = gills on the side of the cowl, no help.
I = temporarily attached a scoop to force more air in the duct, no = help.
 
I = finally discovered that the air was backed up in the NACA duct plenum = (or chamber), thus cutting off air flow.  I used Micro to smoothly = shape the chamber, thus directing the air into its 3" outlet (no more = dead corners) with the results detailed above.
 
Good Luck,
=
 
Scott Krueger AKA Grayhawk
Lancair N92EX = IO320 SB 89/96
Aurora, IL (KARR)

=
In a message dated 3/9/2009 12:41:32 P.M. Central = Daylight Time, marv@lancair.net = writes:
Posted for randy snarr <randylsnarr@yahoo.com>:
 All,
 Thanks for the good suggestions on the oil = cooler.
 I flew again today and my oil temps are at 208 F = flying in 35 f air.
 They will be 215 or 220 this = summer.
 I will try a few solutions that do not need to cut the = cowl. I will most
likely make a duct to carry the exhaust air from = the oil cooler down to the
lower aft part of the cowl. I have also = heard that the aft vertical edge of
the naca opening should be = shaped like an air foil. Mine is flat and fairly
sharp. The = easiest way to test will to be construct a piece to give it a =
little airfoil made from balsa or foam taped in place and flight = tested. If
that does not work, I will make a duct from the cooler = to the low pressure
area on the bottom of the cowl and lastly = would be a small lip on the bottom
of the cowl aft.
 every = producton airplane I have seen with an opening on the bottom of the =
cowl has 45 deg lip to create a low pressure area. I should have = done that
before I painted....
 
 
 I will = post my findings when I get them.
 
 Randy = Snarr
 N694RS
 


--

SFor archives and unsub http://mail.=
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A Good Credit Score is 700 or = Above. See yours in just 2 easy = steps!

=

= --Apple-Mail-52-865374837--