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