Engine Cowl Outlet

[Steve W]

Does anyone who is now flying with good engine temps know the out area (inches squared) of their cowl? I think I'm short of the 1.5 times the inlet area. My cowl is wrapped really tight and ended up with very little depth to the bottom.
Thanks

Steve W P203

[Bdflies]

I’m not near the Patrol, but I’ll check when I get home. I know I’m not at 150% exit area either. Not close. My CHTs were always good (below 365 in cruise), but oil temperature was high until the engine was fully broken in. The cooling lip made a really big difference on mine.

Bill

[Steve W]

Thanks Bill. I really would appreciate it. I have always tried to ensure the outlet is at least 1.5 times the inlet as most of the planes I have built go on floats. I got into some articles on cowl construction today and some feel only 10% is enough. I don't go along with that unless the design has a respectable airspeed but the trouble starts when you put on floats. I watched this happen with some Murphy planes. A lot of builders were using the high speed cowl with success but had major cooling issues when re-configured to floats.
Right now I have an exit about 5 11/16 " X 18 which is about 102 inches squared. I will be cleaning up the outlet area and hope to gain another 9 inches which is closer to where I want to be.