Feb '09 KOTM - John King

[Birddog]

What an impressive build.
I am curious about your radiator modification. From your two pictures I can tell where your radiator is located. The radiator sort of looks like it is positioned on the bottom-rear where exhaust is coming out. Is this true?
I am also curious about how big a range of CHT temp you were getting. Couldn't you just change the mixture of the engine if you didn't like the CHT?
I ask because I will soon be entering the engine installation phase of my project and where the radiator goes is a rather large decision.

Once again, beautiful plane.
Tyler

Tyler,

The radiator cowl flap is mounted directly onto the rear side of the radiator and covers its entire rear surface. All of the outside air that passes through the radiator must flow through the cowl flap. If you fly in extreme weather where temperatures can vary between -10°F to 90°F, and you have a water cooled engine, there has to be a way to control the cooling effects of the radiator. When I flew to Maine in February of 2006 I had the cowl completely closed down in flight at 3000 feet MSL. The CHT was barely 180°F and that was with the cabin heater shut down. When I turned on the cabin heater the CHT dropped down further. I also have flown in Florida in the summer and the Bahamas where you need all the radiator you can get. It is much easier to control the air through the radiator with a cockpit control than have to land and cover up the radiator in cold temperatures. As the temperature varies in flight, I use the radiator cowl flap control to maintain a constant CHT.

If interested I can send you a lot more pictures of the cowl flap in the construction phase to your e-mail address.

John
Warrenton, VA

[mcguif0a]

My email address is mcguif0a@erau.edu
I would be very interested to see these pictures.
Tyler