I'm with you, guys. My '62 Deb has the same issue on climb-out.
I often see temps just above 410, but only on #6, and only until I can get her to pattern altitude and nose her down to pick up some speed. If I climb out below 120 knots... back up it goes.
Has anyone here seen or performed the airflow mod on the CSOBeech site (http://csobeech.com/Bo-Flow.html
). This seems to make a lot of sense, especially once you look down there and see the labyrinth that is the nosebowl structure. This mod cleans that up.
I can confirm the claim on the CSOBeech page that the air flows back out the front of the cowl. When I had a pushrod tube leak, the oil would mist and get on the windscreen. There was no streaking on the cowl hinges, but the back of the prop close to the spinner also had a misting of oil on it. When we replaced the pushrod tube grommets that problem went away.
I also wonder if the little "lip" on the bottom of the cowl, where the cowl flaps would be, isn't also messing up the airflow, especially at high angles of attach that we see at takeoff. I can't help but think that between the high angle and the sharp edge, the air isn't practically being pushed up from the bottom as it burbles over that hard edge (
For now, I just get to an altitude where I can reduce my AOA as quickly as possible and proceed to cruise/climb to keep things below 400, even if just barely below.