The P-51 Scoop is how I plan on cooling my 20B (Long-EZ)

 

I scaled down the drawings of the original P-51 plans in Auto CAD and fit it into my plan drawing and it looks as though it will make for a nice compact design.

 

The original P-51 design splits the airfow sending a portion to the oil cooler and the rest to the radiator. Both have a controlable exhaust door to meter the airflow leaving the unit.

 

The original P-51 has no thermostat. Temperature is regulated by the position of the exhaust door. On takeoff and landing the doors are wide open. The rest of the time they are automatically controlled to regulate the temperatures.

 

I'm just about to the point where I will be flipping my bird on it's back in order to install the cooling system.

 

The P-51 design (if done correctly) can create enough thrust to cancel out 90% of the drag caused by the scoop.