Mailing List flyrotary@lancaironline.net Message #61545
From: Bill Bradburry <flyrotary@lancaironline.net>
Subject: RE: [FlyRotary] Re: swirl / expansion tank configuration
Date: Thu, 29 Jan 2015 14:05:26 -0600
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

Thanks, Steve.

 

What was going on when the water temp and pressure spiked?  Was this during the climb up to 11.5K?  The OAT was pretty low..~40 degrees, does the thin air have that much of a negative effect on cooling?  I am a flatlander and have never had occasion to get up that high.  :>(

 

I am leaving about a pint or so of air in the top of my expansion tank.  The pressure goes to the cap pressure and is pretty stable there.  I wonder if I should leave more space?  I have never noticed any leakage of coolant out of the overflow, but it goes overboard if it leaks, and I should see coolant residue I think.

 

Bill

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Thursday, January 29, 2015 11:34 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: swirl / expansion tank configuration

 

Bill,

 

Attached is a plot of coolant temperature, coolant pressure, outside air temperature, and IAS for a recent flight.  The flight consisted of two touch and go's, a climb from 7200 ft to 11,500 ft MSL, a series of stalls, slow flight, steep turns, and a descent to landing.  A stock type thermostat is used and a 14 psi cap is installed on the expansion tank which has at least a quart of air space when cold.

 

Steve Boese

RV6A, 1986 13B NA, RD1A, EC2


From: Rotary motors in aircraft <flyrotary@lancaironline.net> on behalf of Bill Bradburry <flyrotary@lancaironline.net>
Sent: Thursday, January 29, 2015 9:28 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: swirl / expansion tank configuration

 

Seeing Lynn’s cooling system again gives me an easy way to ask my question.  I have been unable to locate a filler cap similar to the one that is shown on top of the propane bottle.  I can only find pressure caps like the Stant lever cap shown on top of the RX-3 bottle.

Does anyone have a source or can suggest one for a radiator filler cap?

 

Also I am wondering about the pressures that others are seeing in their systems.  I have a 21 pound cap on my system and the pressure immediately goes to that pressure and stays there for the duration of the flight.  I think that others have seen pressures that are lower from time to time during the flight and I would appreciate some anecdotal evidence if others see different pressures.

 

Bill B

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