X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao105.cox.net ([68.230.241.41] verified) by logan.com (CommuniGate Pro SMTP 5.2.6) with ESMTP id 3060125 for flyrotary@lancaironline.net; Mon, 04 Aug 2008 02:09:52 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.41; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao105.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20080804060912.KALV774.fed1rmmtao105.cox.net@fed1rmimpo02.cox.net> for ; Mon, 4 Aug 2008 02:09:12 -0400 Received: from BigAl ([72.192.137.74]) by fed1rmimpo02.cox.net with bizsmtp id y69C1Z0021cVYgg0469CsN; Mon, 04 Aug 2008 02:09:12 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Back in the air Date: Sun, 3 Aug 2008 23:10:07 -0800 Message-ID: <000001c8f601$2066b020$6401a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C8F5BE.12437020" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C8F5BE.12437020 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable With a pusher, a fan is pretty much a necessity for cooling on the = ground. On my Velocity I found that the negative pressure from the prop did = result in some airflow through the rad in the cowl; which did OK on cool days, = but fan made a significant difference, and now taxing and waiting for = takeoff clearance on not an issue even on hot days. =20 I have found that the fan makes no noticeable difference on cooling when = at flight speeds whether on or off; and the cooling in flight is not = reduced since installing the fan. I think if you had waited a bit longer in = flight the temp would have come down without the fan on; other wise I would not expect it to stay stable at 180 without the fan. =20 Al =20 The new cooling system also has a cooling fan which I was able to = integrate into the plenum holding the radiator. At 95 F degrees OAT, and turning = the fan on at about 190 F degrees coolant temperature, The fan maintained = 180 F for 20 minutes of ground operation, including some high power testing. =20 This morning OAT was about 78 F, which is very good for North Carolina = in August, I wanted something less than 95 F for the first test of the new cooling system. I did not use the cooling fan for taxi or takeoff, as I wanted to see what the cooling was without the fan. I took of and = climbed up to about 1200' AGL. The coolant was up to about 205, and oil at 185. = I leveled off and reduced the throttle to normal cruise power. I watched = the coolant temperature for a little while (maybe 15-20 seconds), and it = seemed to stay at the 205 F reading. I wish now that I'd been a little more patient, but I kicked on the cooling fan, and the temperature came down pretty quickly to slightly above 180 F. I turned the fan off again and = the temperature stayed right there. I did power up and climb another 300 = feet or so, but really didn't push it too hard on the first flight. The temperature didn't really move too much during the brief climb. All = other systems ran perfectly and it was a very nice flight. I did stay within gliding distance of the runway the whole flight, but based on zero = squawks on this flight, the next one will be longer. =20 While I would like to have seen a little better performance, I was happy with the improved cooling over the old system. Climbing to pattern = altitude old the old system at today's temperature would have been 215 - 220F. = On the next flight, I'll take off using the cooling fan, and see what kind = of numbers I get with it. I hope to see something more in the 185-190 = range, but I'll have to see what the real number are.=20 =20 =20 Steve Brooks Cozy MKIV N75CZ Turbo rotary ------=_NextPart_000_0001_01C8F5BE.12437020 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

With a pusher, a fan is pretty = much a necessity for cooling on the ground.  On my Velocity I found that = the negative pressure from the prop did result in some airflow through the = rad in the cowl; which did OK on cool days, but fan made a significant = difference, and now taxing and waiting for takeoff clearance on not an issue even on hot = days.

 

I have found that the fan makes = no noticeable difference on cooling when at flight speeds whether on or off; and the = cooling in flight is not reduced since installing the fan.  I think if you had = waited a bit longer in flight the temp would have come down without the fan on; = other wise I would not expect it to stay stable at 180 without the = fan.

 

Al

 

The = new cooling system also has a cooling fan which I was able to integrate into the = plenum holding the radiator.  At 95 F degrees OAT, and turning the fan on = at about 190 F degrees coolant temperature, The fan maintained 180 F for 20 minutes of ground operation, including some high power = testing.

 

This morning OAT was about 78 F, which is very good for North Carolina in August,  I wanted something less than 95 F for the = first test of the new cooling system.  I did not use the cooling fan for taxi = or takeoff, as I wanted to see what the cooling was without the fan.  = I took of and climbed up to about 1200’ AGL.  The coolant was up to = about 205, and oil at 185.  I leveled off and reduced the throttle to = normal cruise power.  I watched the coolant temperature for a little while = (maybe 15-20 seconds), and it seemed to stay at the 205 F reading.  I wish = now that I’d been a little more patient, but I kicked on the cooling = fan, and the temperature came down pretty quickly to slightly above 180 F.  = I turned the fan off again and the temperature stayed right there.  I = did power up and climb another 300 feet or so, but really didn’t push = it too hard on the first flight.  The temperature didn’t really move = too much during the brief climb.  All other systems ran perfectly and = it was a very nice flight.  I did stay within gliding distance of the runway = the whole flight, but based on zero squawks on this flight, the next one = will be longer.

 

While I would like to have seen a little better performance, I was happy with the improved = cooling over the old system.  Climbing to pattern altitude old the old = system at today’s temperature would have been 215 – 220F.  On the = next flight, I’ll take off using the cooling fan, and see what kind of = numbers I get with it.  I hope to see something more in the 185-190 range, = but I’ll have to see what the real number are. =

 

 

Steve Brooks

Cozy MKIV N75CZ

Turbo rotary

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