I did the first “post-cure” of the custom cowl todayJ, that is, first runs with cowl on; and the faired spinner.  The big high for the day was finding that the negative pressure created by the prop, even at low rpm, drew significant cooling air through the radiator in the cowl and out the back.  Previous runs without the cowl had me convinced that I would need an auxiliary fan for idle and taxi time.  First indication I had was with the prop only at 700 rpm, I put my hand in front of the rad intake scoop and was surprised at the amount of air flow going in. 

I did simulated taxi and stop running; a bit over 2000 on the engine for a while, then some 1600, then some 2000; for about 10 minutes.  Temps got up to 200 on the oil and 195 on the coolant, and were pretty steady there. It was a 70 degree day, so it may not work on a 90 degree day; but I was very pleased.  I also think it is going to give me clean airflow into the prop.

(and I liked the way it looked, the third photo is the stock cowl for a Lyc).

It’s these bright spots that keep us going on these projects.

Al (stock Lyc – Nyet!     Rotory – Da!)