From: Ron Montgomery <diver32533@...>
Date: July 29, 2019 at 1:06:01 PM CDT
To: Cozy Builders <cozy_builders@...>
Subject: Engine cooling

I am in the process of reworking my engine cooling after performing a complete engine overhaul. I have an IO-360 with 10 to 1 pistons, tuned 4 into 1 exhaust and dual Plasma ignitions , with downdraft cooling.
Prior to my engine overhaul I had a pressure differential of 6 inches of water as measured with a Magnehelic gauge. With that set up I always had to power back on takeoff to lower head temps. During my down time for the engine overhaul I did a lot of cowling work and engine baffling modifications.
On my first flight I only had 4 inches of water. Needless to say my head temps were out of control. I had closed off 2/3 of my cooling air exits during the overhaul. I cut two small openings in the bottom of my cowl and installed ramps 1 inch in front of the new openings, and also a ramp in front of my exhaust opening. Next flight I had 8 inches of pressure difference. My head temps have never been this good . I can easily manage temps.
My question to the group is this. Is it possible to install another opening with a ramp and go over 8 inches ? It seems to me if I could get to 10 inches difference I would not have to worry about head temps at all. Is there a maximum pressure difference that can be reached ?
Should I leave well enough alone ?

Ron Montgomery
Cozy MK IV   150 hrs