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

 

 

Charlie, I don’t think your system will work as you expect and I’m pretty sure it is not the same as the Hanover-Setup.  Attached is the Hanover cooling system diagram … note all the cooling elements (radiator, hoses, filler bottle) are completely full of glycol (green); only the expansion tank (approx 1 litre, with stant lever cap) has room for air, filled only about 1/3.  The location of the expansion tank is shown higher than everything else in the diagram but can actually be located lower; what is important is the connections be as shown, i.e., highest point of saturated cooling system connects to bottom of expansion tank, expansion tank is only 1/3 full and this is where you install the pressure cap.

 

The location of your steam lines to top of expansion tank is correct but I think with your bottom connection going to pump inlet what will happens is any portion of the expansion tank lower than highest point in the system will simply back-fill with coolant and you will no longer have an expansion tank but rather a coolant tank.  I believe your methodology will work if at least 1/3 of expansion tank is the highest point in the system.  One thing for sure is with the pressure sensor located on the pump inlet side, you will be measuring the lowest pressure in the system.

 

Jeff

 

From: Charlie England <flyrotary@lancaironline.net> Subject: swirl / expansion tank configuration Date: Wed, 28 Jan 2015 17:57:34 -0600 To: flyrotary <flyrotary@lancaironline.net>

I'm setting up the cooling plumbing for the Renesis (RV-7) & wanted to try the setup used in a lot of current autos, where the 'steam' lines go to the expansion tank and the coolant in the expansion tank is constantly pulled back into the input to the water pump. I'm hoping that this will do a continuous purge, similar to Lynn Hanover's setup with the extra swirl tank. I couldn't get the swirl/expansion tank higher than the water pump outlet (highest point of the system), so I modified the hotrod expansion tank shown, with the hope that when the system cools, it will be forced to pull only coolant back into the 'steam' lines. The plan is to collect the steam lines from the radiator, flywheel end iron, and pump outlet & return them to the port located at the 10 o'clock position on the tank. I'm assuming that I'll need to add a fill port on the pump outlet (top of engine) and fill from there after partially filling & capping the expansion tank. Any thoughts/criticisms? Charlie

 

 

 

 

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