Hi rawheels, the bottom opening in my cowl is 16" X 3" the venturi lip is 1.5" I was out flying this evening and here are some numbers: OAT 71*F, EGT's Right=1257*F Left= 1281*F CHT's L=305*F Right+ 305*F oil temp= 176*F RPM's 5500 MSL = 2000' Density alt = 2800' carb air temp = 22*C IAS 77 mph oil pressure = 64 PSI.
I looked at your pictures (I know you may not appreciate this but) the oil cooler installation looks great but you are dumping lots and lots of hot air to the bottom of the engine and loading the cowl with hot air, this may work good while in flight but on the ground with very little air flow not so good. As for the baffles the KIS system is best they do not need to be elaborate they just have to direct the incoming air around the cylinders and that's what mind do. Good luck hope you get in the air soon it was a good night for flying here in MN.