A sincere thank you Walter, i am in the process of modifying the engine cowl of my aircraft, and have heard during the APS course of the cooling misconceptions, now you have inspired my to get the gopro out, some wire and tuffs, to do some testing on my own aircraft before i start rehaping, or moving cooling air inlets to the rear to take advantage of the stagnet air(higher pressure) in front of the windscreen, considering the new prop and spinner combination now covers most of the original front inlet, leaving only approx 2 inch gap either side of the spinner. my theory is to close off the nose inlets completly, and move the intake to the upper rear of the cowl, and direct the cooling air forward with internal ducting to above the cylinder heads, and continue down to the lower deck and out the convnetional manner. as for cooling on the ground, the engine is partially fluid cooled and oil cooled.
Good on you.
There are some really good technical papers on this that have been presented to the AIAA (from memory). The keywords are pressure recovery, engine cowl, general aviation.
Here's one to get you going, but I think you'll find better ones.
http://www.n91cz.com/Interesting_Tec...AA_80-1242.pdf
The key issue is to turn the kinetic energy of the high speed air inlet into static pressure in the upper deck of the engine and to have a pressure drop access the engine to get the cooling air to go where you want it. From memory, the pressure drop from the top of the engine to the bottom is typically 4psi. Walter might recall the real number. But its relatively small, so finess is required.
You might end up replacing your wool tufts with manometer plumbing.