Lynn,

You sent that drawing some time ago during a previous discussion on cooling.  My system is set up very similar, but I wonder what the effects of the differences might be. 

I don’t have a swirl pot, but the cap on the radiator is like in your drawing where it doesn’t seal for pressure.  Another difference is that my radiator is a double pass, so the radiator cap is after the first pass of the radiator.  You don’t show where you come in with the air bleed from the top of the front iron.  Mine comes in just under the radiator cap.  This allows the air to move into the make up bottle quickly.  But the down side is that whatever coolant comes thru that ¼ inch line bypasses the first pass of the radiator and only goes thru the last pass.  However, I think that this coolant has only made one pass thru the engine as well.

( I have no clue how the coolant flows thru the block, but I think it goes down one side and back up the other side to the water pump???)  I would like someone to set me straight on this coolant flow thru the engine.  There are two outlets, this one and the heater supply that come off the front iron.  They must somehow only get contact with half the engine since the water pump is on the other end of the engine. ???

Bill B

You need some kind of header/expansion tank in sys. with aprox 4 to 8 square inches of air, allows sys. to pressurise more easily & maintains a steady pressure.   David Cook  RV6A  Rotary.

Here is one system that works perfectly and has since 1980. For Mazda before that. The swirl tank idea comes with the instructions for each New CosWorth race engine. The restrictor idea is mine. The pressure cap only on the make up bottle (and the actual bottle in my case) is the stock layout from every RX-2 and RX-3 imported to the USA. The swirl pot is not required, it just works very fast, and my system is apart often. So I use it.

The tube to the bottle comes off of the radiator in the cars. In the airplane it would need to come from the location where ever air would likely collect. In most cases, the highest part of the water pump outlet, or the top of the rear iron. With the engine dead level in the racer, this system removes all of the air in 2 heat cycles. The fluid level must be replenished twice. I keep the bottle about 1/3 full to allow 2/3 to be compressible air. It is an accumulator just like big airplanes, and big heating systems and boilers.

No need to reinvent the wheel.

Lynn E. Hanover