Spent 3 hours last night fabricating this cowling exit fairing from 0.016" stock. Bent the half-inch flange first, then used a 1.25" diameter aluminum tube to form the gentle curves seen here. Images 2 and 3 really show the smooth exit the air coming through the cooling inlets will make as it leaves the engine compartment. This isn't my idea; apparently this standard on several production aircraft. The fairing reduces the turbulence as the heated air exits the cowl and significantly improves the cooling efficiency of air flowing through the compartment. Doesn't weigh much and it can't hurt, so why not?