RE: Is this enough engine cooling?
Here are some pictures to illustrate.
The picture from the front partly shows the baffle I placed behind the "worthless" opening. The baffle is about an inch back from the opening and is at an angle. If you could see it from the inside (sorry, but I didn't feel like pulling the cowl for pictures inside) it is glued to the top of the cowl and down the side.
There are two pictures of the bottom. One looks straight down on the bottom. The area of the exhaust opening, if measured at that angle, would be worthless. That opening could be hacked all the way to the tail of the airplane and it wouldn't do one bit better as an exhaust. The picture that looks up inside comes closer to showing the actual size of the true exhaust area.
I've guessed at the true area of the exhaust and it's actually maybe not even equal to the two intake openings. If it is larger, good deal. As it happens, I've been flying in the hottest days we've had this summer and that engine acts like it did in the spring.