X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [207.115.11.53] (HELO fmailhost01.isp.att.net) by logan.com (CommuniGate Pro SMTP 5.2.2) with ESMTP id 2900147 for flyrotary@lancaironline.net; Mon, 05 May 2008 20:56:55 -0400 Received-SPF: pass receiver=logan.com; client-ip=207.115.11.53; envelope-from=bbradburry@bellsouth.net Received: from desktop (adsl-210-53-36.mco.bellsouth.net[68.210.53.36]) by isp.att.net (frfwmhc03) with SMTP id <20080506005616H0300s1oale>; Tue, 6 May 2008 00:56:16 +0000 X-Originating-IP: [68.210.53.36] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: Cooling system changes- Velocity 20B Date: Mon, 5 May 2008 20:56:16 -0400 Message-ID: <7DBAE2DB178045BC94FC55BE2098F382@Desktop> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000D_01C8AEF2.763F2EB0" X-Mailer: Microsoft Office Outlook 11 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6000.16545 Thread-Index: AcivDi7StaXYSj6GQkad8KPIHXiU4wABFFPg This is a multi-part message in MIME format. ------=_NextPart_000_000D_01C8AEF2.763F2EB0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Al, How well does your engine cool on the ground? What is the max rpm that your coolant temp will stabilize within your upper limit and what is the temp at that rpm? Do you have any fans or otherwise pulling air thru the radiators when sitting on the ground? Tracy tells me that I should be able to run 2600 rpm or so and stabilize under 230 degrees on my Renesis, but it is not happening. I am hoping that it will cool when air is moving in flight, but I assume that if I don't meet the basic cooling requirement, it will not cool in flight either. I am wondering what others are getting for static cooling? Bill B _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen Sent: Monday, May 05, 2008 8:18 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Cooling system changes- Velocity 20B I thought it was a bit of a mystery that now that I am dumping heat from the oil/water heat exchanger to the coolant, the coolant temp is lower, even with the thermostat to the second radiator closed (yes, there are some small holes in the thermostat, but it's a tiny flow area - 0.02 sq. in.). It finally occurred to me that the second radiator, being very ineffectual as it was, was basically a bypass of the effective radiator in the cowl. Now that it is blocked by the thermostat, the increased flow through the effective radiator is lowering the coolant temp. In effect, this says that the 460 cu. in of rad core volume is adequate for cooling my 20B, even when dumping some oil heat load into it. It's in the neighborhood of 2.3 cu. in. per hp out. Shows you what an effective scoop and diffuser can do. Al -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Lehanover@aol.com Sent: Tuesday, April 29, 2008 12:46 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Cooling system changes- Velocity 20B In a message dated 4/29/2008 12:50:27 PM Pacific Daylight Time, ALVentures@cox.net writes: I drilled three 5/32" holes in the thermostat to keep some flow going through not thinking that would provide any significant cooling, but I guess it does. First step is to replace the thermostat; then see if it might be appropriate to reduce the airflow into the in-cowl rad - in some way that reduces drag. But the nice thing is there is no urgency - and my flight regime is not limited. I use a 180 degree thermostat with a single 1/8" hole to allow air to escape. On cold days the engine runs under 180 on yellow laps. That 1/8" hole is enough flow to cool the engine. For best power, 160 degrees on the oil is as high as you need. Lynn E. Hanover _____ Need a new ride? Check out the largest site for U.S. used car listings at AOL Autos . ------=_NextPart_000_000D_01C8AEF2.763F2EB0 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Al,

How well does your engine cool on the ground?  What is the = max rpm that your coolant temp will stabilize within your upper limit and what = is the temp at that rpm? 

Do you have any fans or otherwise pulling air thru the radiators = when sitting on the ground? 

Tracy tells me that I should be able to run 2600 rpm or so and stabilize under = 230 degrees on my Renesis, but it is not happening. 

I am hoping that it will cool when air is moving in flight, but = I assume that if I don’t meet the basic cooling requirement, it will not = cool in flight either.

I am wondering what others are getting for static = cooling?

 

Bill B

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen
Sent: Monday, May 05, = 2008 8:18 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Cooling system changes- Velocity 20B

I thought it was a bit of a = mystery that now that I am dumping heat from the oil/water heat exchanger to the = coolant, the coolant temp is lower, even with the thermostat to the second = radiator closed (yes, there are some small holes in the thermostat, but = it’s a tiny flow area - 0.02 sq. in.).  It finally occurred to me that the = second radiator, being very ineffectual as it was, was basically a bypass of = the effective radiator in the cowl.  Now that it is blocked by the = thermostat, the increased flow through the effective radiator is lowering the = coolant temp.

 

In effect, this says that the 460 = cu. in of rad core volume is adequate for cooling my 20B, even when dumping = some oil heat load into it. It’s in the neighborhood of 2.3 cu. in. per hp out.  Shows you what an effective scoop and diffuser can = do.

 

Al

 

-----Original = Message-----
From: Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] On Behalf Of Lehanover@aol.com
Sent: Tuesday, April 29, = 2008 12:46 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Cooling system changes- Velocity 20B

 

In a message dated = 4/29/2008 12:50:27 PM Pacific Daylight Time, ALVentures@cox.net = writes:

I drilled three 5/32” holes in the thermostat to keep some flow = going through not thinking that would provide any significant cooling, but I = guess it does.  First step is to replace the thermostat; then see if it = might be appropriate to reduce the airflow into the in-cowl rad – in some = way that reduces drag.  But the nice thing is there is no urgency – = and my flight regime is not limited.

 

I use a 180 degree = thermostat with a single 1/8" hole to allow air to escape. On cold days the engine = runs under 180 on yellow laps. That 1/8" hole is enough flow to cool the engine.

 

For best power, 160 degrees = on the oil is as high as you need.

 

Lynn E. = Hanover

 

Need a new ride? Check out the largest site for U.S. used car listings at = AOL = Autos.

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