Mailing List flyrotary@lancaironline.net Message #23423
From: al p wick <alwick@juno.com>
Subject: Re: [FlyRotary] Re: Remaining pressure when cold (Re: coolant leak)
Date: Thu, 9 Jun 2005 06:58:12 -0700
To: <flyrotary@lancaironline.net>
Yes, please test your theory David and get back to us. I'm unable to comprehend how you are able to maintain pressure long after shutdown. At some point, you have hot liquid (or air) that cools. That must result in substantial pressure drop. Maybe I'm overlooking something.
 
-al wick
 
On Wed, 8 Jun 2005 20:02:31 -0700 David Leonard <wdleonard@gmail.com> writes:

 
On 6/8/05, Russell Duffy <13brv3@bellsouth.net> wrote:

 >>>> You have a compression leak if.... <<<<

Very nice write-up Bill.  
 
I agree bill, thanks.

 
Dave, I've got to agree that I've never seen pressure after cool down on any cooling system.  Do you have something unusual about your system, like two different pressure caps, or anything else that might make it behave abnormally?  
 
Yes, exactly, two pressure caps in series.  The second tank is one qt and I keep it empty.  The first tank is about a pint and I keep it full.  First pressure cap i s 13 psi, and second tank is 20.  Pressure sensor (switch only) is on  the second tank. 
 
The second tank acts as my air spring.  (see other post)
 
 
I believe the "normal" way to test for this is to use a coolant pressure tester, or any other method you can devise to pressurize the system.   I'm thinking you could easily have a leak that allowed combustion pressure to get through, but would never let coolant pressure through, particularly pushing liquid. 
 
It would be easy enough to pressurize the coolant system to about 30 psi and see if the coolant goes into your new turbo.  Also, isn't there a test you can do where you send a sample of coolant out to be tested for combustion gasses?  That might be easier, and more likely to give a final answer. 
 
To test, I could remove the cap from my second tank and run the engine.  There should now be no pressure under cap number 1 after cool down.  I will do that test in the near future.... 

 
I sure hope it's not leaking Dave.  I guess this is another warning sign that I'll never get with my zero pressure system, though if I blow too many bubbles, the low coolant light will come on. 
 
Cheers,
Rusty (zero pressure / ignorance is bliss)
 
 
I am now running the Evans Coolant too, but I changed my system.  the first cap is now zero psi and the second is still 16 psi.  I imagine my over pressure is less than 7-10 psi but it still allows me to check the system for leaks with the pressure sensor.

--
Dave Leonard
Turbo Rotary RV-6 N4VY
http://members.aol.com/_ht_a/rotaryroster/index.html
http://members.aol.com/vp4skydoc/index.html
 

-al wick
Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install, Risk assessment, Glass panel design info:
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