Dave,
One thing that caused me a bunch of head-scratching was the bypass circuit in the water pump housing when first filling the cooling system.  It can prevent the wp impeller from pumping coolant through the engine.  That is where I would look first.  Did you weld and/or plug the hole at the bottom of the thermostat?  If so, you could have air trapped in that cavity.  If you installed a screw-in plug, try removing it and then filling the system, then replace the plug.  If you're running a thermostat, have you removed it to fill the system? 

Mark S.


 At 02:53 PM 4/6/2004 -0400, you wrote:

 
 
----- Original Message -----
From: Ed Anderson
To: Rotary motors in aircraft
Sent: Tuesday, April 06, 2004 8:38 AM
Subject: Re: [FlyRotary] Re: idle speeds

Dreadful to hear about your problem, Dave
 
    My first six port had about 40 hours on it when I also discovered a coolant leak into number 2 rotor.  It also was the results of some overheating before I discovered that I had to "burp" the engine.  That engine was built for me using the stock coolant "O" rings.  I have since used the TES coolant "O" rings in both the rebuild of the six port as well as my current turbo II block and even though I have overheated the turbo II block (trying to get *&^%$ thermostats to work for me) I have had no recurrence of the coolant leaks.  You probably only need the TES type for the "inner" rings, I continue to use the stock outer rings.
 
    But, I agree, you need to find out why your setup is failing to cool.  As I recall you have a large radiator sitting under the block.  If I recall correctly its sitting at a fairly steep angle to the airflow.  If you are running the engine without a cowl/duct to capture your prop wash and force it through the fins, you may not be getting sufficient airflow through it.  I think someone suggest going to Home Depot/Loews and getting some of that large reinforced clear plastic hose and replace part of your hose runs with that.  I might provide some visual clues to what is going on. 
 
   After all there are only two possibilities.  Your coolant flow is insufficient to remove the engine heat at an adequate rate from the engine OR the radiator is not rejecting sufficient heat into the airstream (could be a bit of both I guess).  Determining why one or the other of those conditions exists of course is the challenge.  With the clear plastic hose, you should be able to get some idea of the flow rate.  If you wanted to get techie, you could try to time bubble flow speed along a measure section of that hose and using the cross sectional area of the hose to estimate a flow rate.  For that purpose you might want to insert several feet of hose into your circuit some place.
 
  I would suggest you try these things before tearing down the engine.  I ran my six port for about 10 hours with the leak (but it sounds like it was somewhat smaller leak that you have).  As you well know, not much point in rebuilding the engine with that problem unresolved.  If coolant flow appears to be adequate, then that would narrow it down to the functioning of your radiator.  If you don't have a duct built already, it might be worthwhile to mock one up to direct the airflow more directly into your radiator.
 
Ed Anderson
  
 
 
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC

----- Original Message -----

From: David Leonard

To: Rotary motors in aircraft

Sent: Tuesday, April 06, 2004 12:10 AM

Subject: [FlyRotary] Re: idle speeds

Yes, unfortunately true.  I was having those problems trying to get the coolant to circulate.  I thought I was getting a handle on it.  The system was thoroughly burped.  At 2000 RPM the coolant was level at about 140.  At 3000 it would cool to about 100.  This told me that I was just circulating a little better at the higher RPM.  After about 5 min at 4000 RPM the coolant temp was  still only 150 when coolant began to spray the canopy.  I thought for sure I had a big enough catch can.  At first I couldn’t figure out where the coolant was coming from.  Until, to my utter dismay, I discovered it was coming from the oil vent line.  L 

 

I had coolant dripping from the exhaust and spilling out around the injectors.  I was so disgusted with the whole project I didn’t even want to think about it.  The next day I pressurized the cooling system and found a very slow leak of coolant into the front rotor chamber (as evidenced by the spray of coolant into the eye as I peered into the open spark plug hole and turned the prop – highly NOT recommended).

 

I still have good compression all around, I just need to replace the water o-rings.  I am going to use the TES o-rings.  But even that won’t help if I can’t solve this damn circulation problem.  I am really at whit’s end.  There is no reason I shouldn’t be making coolant go round and round. 

 

With my work schedule re-building the engine will only set me back about …  3 months.  Will make it thought to get to the next rotary roundup.

 

David  (It could be worse, I could have to do a bunch more fiberglass work.) Leonard

The Rotary Roster:

http://members.aol.com/_ht_a/rotaryroster/index.html

David Leonard (working on the cowl while I await parts to re-build the

engine)

 

Re-build the engine?  Did the cooling problems damage something?  Man, I sure hope that's not what you really meant.

 

Rusty