X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao104.cox.net ([68.230.241.42] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTP id 3859217 for flyrotary@lancaironline.net; Fri, 18 Sep 2009 22:21:04 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.42; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo01.cox.net ([70.169.32.71]) by fed1rmmtao104.cox.net (InterMail vM.8.00.01.00 201-2244-105-20090324) with ESMTP id <20090919022027.MWBH14181.fed1rmmtao104.cox.net@fed1rmimpo01.cox.net> for ; Fri, 18 Sep 2009 22:20:27 -0400 Received: from wills ([68.105.90.215]) by fed1rmimpo01.cox.net with bizsmtp id iSLR1c0094emyWU03SLTw3; Fri, 18 Sep 2009 22:20:27 -0400 X-VR-Score: 0.00 X-Authority-Analysis: v=1.0 c=1 a=EdP763O_P0MA:10 a=3oc9M9_CAAAA:8 a=7g1VtSJxAAAA:8 a=Ia-xEzejAAAA:8 a=qzzzj5MVB0xwRcxrSicA:9 a=oD13lxXzuLI4MfrzcQYA:7 a=VtLif3-c5ILVl3--dGh7P2cl5DAA:4 a=U8Ie8EnqySEA:10 a=UretUmmEAAAA:8 a=waMTNcpWK4IcFDEy-vQA:9 a=3G29OPoBcE82mRhHlhkA:7 a=WFrMxg0fNs4UvuMBmqk0njHFmJ8A:4 a=iVkDmfvjeKcA:10 a=EzXvWhQp4_cA:10 X-CM-Score: 0.00 Message-ID: From: "Mike Wills" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Re RV-8 cooling test Date: Fri, 18 Sep 2009 19:20:26 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0066_01CA3895.136D1940" 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 This is a multi-part message in MIME format. ------=_NextPart_000_0066_01CA3895.136D1940 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable You could just try duct taping a bent tab at the leading edge of the = hole to act as a deflector and create low pressure at the hole. Then go = fly it again. Quick and dirty. Wait a minute! Who am I to give advice to the master of all things = rotary? Mike Wills RV-4 N144MW=20 ----- Original Message -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 Sent: Friday, September 18, 2009 5:00 PM Subject: [FlyRotary] Re: Re RV-8 cooling test Because it looked easy to modify the bottom cowl outlet on the RV-8 to = a cowl flap configuration I decided to try that before installing some = louvers in the same area. Attached is a picture of the cowl after I cut = out the area that would form the bottom of cowl flap. =20 Couldn't resist the urge to test fly the plane with that big gaping = hole in the bottom. I was thinking that it would show if it was the = small size of the stock opening that was causing the problem or if = aerodynamic factors dominated. The 'big hole' outlet ran about 10 degrees cooler than stock which was = not nearly the improvement I'm looking for so I can't believe that the = louvers would work in this location. Back to working on the cowl flap = in the hopes that the low pressure area behind it will extract a lot = more air. I don't have a warm fuzzy about it though. After this (if = it doesn't work) I'll try a bluff body extractor vent as described by = some CAFE Foundation reports.=20 Just as a point of reference, I have about 35 sq in of inlet area and = 52 inches of outlet area with the stock cooling outlet. Now I know = that the inlet area is more than large enough (from the cowl off flight = test) and the 52 sq In outlet should be enough but I think the pressure = is too high under the fuselage where the outlet is. Tracy On Thu, Sep 17, 2009 at 6:13 PM, wrote: Thanks for that. I'm making my radiator chin scoop right now. I made a 'buck' out of 2 part pour foam, then cut & sanded to shape. = After laying up the part, and removing it, I began to remove the edges. = Good thing I made it too deep. Now you guys have revisited the = Exit/Inlet relationship issue. A little time with a ruler, some quick math, and some trimming is = leading me right to the reccomended 30% bigger exit area than inlet area = for the radiator. I was going to use Van's original exit, but now I'm = adding about 1/2" more depth. My oil cooler exit area is really over sized. It is kept separate. = The right cowl inlet is ducted to the oil cooler, then exhausted = straight out the right side thru louvers. The left cowl inlet has not been made yet. It will feed air to the = turbocharger and provide surface cooling air for the exhaust system and = fuel injectors. If that chokes the air exit at the bottom, I'll have to = make a left side hot air exit as well.=20 Tracy, your comment about overheated coils and alternator has me = thinking about blast tubes? Scott=20 -------------------------------------------------------------------------= ----- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0066_01CA3895.136D1940 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
You could just try duct taping a bent = tab at the=20 leading edge of the hole to act as a deflector and create low pressure = at the=20 hole. Then go fly it again. Quick and dirty.
 
 Wait a minute! Who am I to = give advice=20 to the master of all things rotary?
 
Mike Wills
RV-4 N144MW 
----- Original Message -----
From:=20 Tracy=20 Crook
Sent: Friday, September 18, = 2009 5:00=20 PM
Subject: [FlyRotary] Re: Re = RV-8 cooling=20 test

Because it looked easy to modify the bottom cowl outlet = on the=20 RV-8 to a cowl flap configuration I decided to try that before = installing some=20 louvers in the same area.  Attached is a picture of the cowl = after I cut=20 out the area that would form the bottom of cowl flap.  =

Couldn't=20 resist the urge to test fly the plane with that big gaping hole in the = bottom.=20   I was thinking that it would show if it was the small size of = the stock=20 opening that was causing the problem or if aerodynamic factors=20 dominated.

The 'big hole' outlet ran about 10 degrees cooler = than stock=20 which was not nearly the improvement I'm looking for so I can't = believe that=20 the louvers would work in this location.  Back to working on the = cowl=20 flap in the hopes that the low pressure area behind it will extract a = lot more=20 air.   I don't have a warm fuzzy about it though.   After = this (if=20 it doesn't work) I'll try a bluff body extractor vent as described by = some=20 CAFE Foundation reports.

Just as a point of reference, I have = about 35=20 sq in of inlet area and 52 inches of outlet area with the stock = cooling=20 outlet.   Now I know that the inlet area is more than large = enough (from=20 the cowl off flight test) and the 52 sq In outlet should be enough but = I think=20 the pressure is too high under the fuselage where the outlet=20 is.

Tracy

On Thu, Sep 17, 2009 at 6:13 PM, <SHIPCHIEF@aol.com> = wrote:
Thanks = for that.
I'm=20 making my radiator chin scoop right now.
I made a 'buck' out of 2 = part=20 pour foam, then cut & sanded to shape. After laying up the part, = and=20 removing it, I began to remove the edges. Good thing I made it too = deep. Now=20 you guys have revisited the Exit/Inlet relationship issue.
A = little time=20 with a ruler, some quick math, and some trimming is leading me right = to the=20 reccomended 30% bigger exit area than inlet area for the radiator. I = was=20 going to use Van's original exit, but now I'm adding about 1/2" more = depth.
My oil cooler exit area is really over sized. It is kept = separate.=20 The right cowl inlet is ducted to the oil cooler, then exhausted = straight=20 out the right side thru louvers.
The left cowl inlet has not been = made=20 yet. It will feed air to the turbocharger and provide surface = cooling air=20 for the exhaust system and fuel injectors. If that chokes the air = exit at=20 the bottom, I'll have to make a left side hot air exit as well. =
Tracy,=20 your comment about overheated coils and alternator has me thinking = about=20 blast tubes?
Scott

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