I just wanted to let you know how well the louvers are working. My new RV7A ran way too hot even after the engine had broken in. The IO-360 cowling in particular does not have enough outlet area for sufficient flow in the tri-gear application since the outlet is mostly obstructed by gear structure. Adding the louvers to the bottom of the cowl underneath each cylinder bank has dropped my CHT's by as much as 40F. I have not been able to detect any loss in speed either so this is a great solution. The attached pictures show that they even look good!
Thanks for promptly sending the louvers. After installation, with all operating parameters being equal, my CHTs dropped an average of 30 deg and my oil temp dropped an average of 20 deg. By average, I am referring to takeoff, climb, and cruise. I am very pleased and you may use me as a testimonial if you want.
Scott Diffenbaugh RV-7A
Installed the louvers this weekend and they work GREAT.
Head cyl temps= Cruse in the 350's leaned, Climb to 6500 ft, 1200 ft min., 130 mph ,never got over 390's.