Mailing List flyrotary@lancaironline.net Message #43704
From: Tracy Crook <tracy@rotaryaviation.com>
Sender: <rwstracy@gmail.com>
Subject: Re: [FlyRotary] 2nd flight on the new cooling system
Date: Mon, 11 Aug 2008 22:07:23 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
It will still freewheel but just a lot slower.  But I still don't like the idea of shorting the leads.  It's basically shorting out a DC generator which will heat up the windings.  Don't know how much.  May not even be enough to worry about.  Still, the idea of wasting the generated electricity just goes against the grain :>)
 
Tracy

On Sun, Aug 10, 2008 at 9:48 AM, Kelly Troyer <keltro@att.net> wrote:
 Steve,
     I believe it was Lynn Hanover that said if you connect the power leads
(+ & - ) together when fan is not powered that it will not freewheel in flight.
 
    Jump in here Lynn and give us one of your sketches on how to wire it
so as not to accidentally switch B+ (12 volts) to ground !!.........
 
--
Kelly Troyer
"Dyke Delta"_13B ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold



 
-------------- Original message from "Steve Brooks" <cozy4pilot@gmail.com>: --------------

George,

 

The cooling fan has some resistance when the power is off, and while I don't know for sure, I doubt that it spins when the power is off.  Form a longevity perspective of the bearings, I hope that it does not.

 

Regards,

 

Steve Brooks

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of George Lendich
Sent: Saturday, August 09, 2008 5:47 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: 2nd flight on the new cooling system

 

Steve,

Does the cooling fan spin freely when turned off or does it remain static. 

Those temps are much better. 

George ( down under)

I took the Cozy up this morning for the 2nd flight on the new cooling system.  The OAT was 3 or 4 degrees warmer than the first flight, as it was 79 F when I took off.

This time, I turned the cooling fan on while I was taxiing out to the runway.  After the  taxi and pre-flight checks, the oil was 135 F and the coolant was still reading pretty low.  Maybe 115 to 120 or so.  It is a little hard to read the analog gauge down on the low end of the scale.

 

I took off and climbed up to about 1300 FT AGL, at which time I pulled the throttle back some and continued a cruise climb.  The coolant was showing about 190F, and I didn't think to check the oil temperature.  Oil temperature has not been my issue.  It has always been the coolant.  The coolant temperature did still increase a little, even at the reduced power, but just up to 200 F.  I was close to a low cloud layer at about 1800 AGL, so I throttle back some more and dropped the nose to level flight.  I also turned off the cooling fan to see what the temperature would do on it's own.  The temperature steadily dropped to about 180 degrees within just a few minutes, and then stabilized there. 

 

I cruised around for a little while, flew over my house and circled it once, and then headed back to the airport.  With the low cloud layer that had moved in, I really didn't know if it was going to clear out or get thicker, so I flew the 5 minutes back to the airport, and made a normal landing.  As I was ready to throttle back to descend about 800 feet to pattern altitude, and quick check of the coolant temperature showed about 160 degrees.  Not bad at all, although I was probably flying at about 60% power.  Still, it would have not been nearly that low before the new cooling system.

 

Once I landed and was clearing the runway, I checked the temperatures again, and the coolant was less then 140 degrees after the glide in to land.  Since I planned to wash the plane, and sometimes it starts hard after getting heat soaked sitting after a run, I turned on the cooling fan while a taxied over to the where the wash area is.  After washing the plane, it started up pretty easily, so I guess that worked out also.

 

So far so good.  I like what I see so far on the radiator, and the cooling fan definitely gives me a lot more options.

 

Steve Brooks

Cozy N75CZ

13B turbo to read the an


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