Question about speed estimating speed
I realize that the engine unloads in a dive....and in flight for that matter; but the efficiency also decreases. The reason a 9 x 8 prop can't exceed 200 mph is that the tips of the prop exceed the speed of sound at 26400. ChuckAuger brings up a very valid point (in a reply above) when he states that the airflow over the prop would reach supersonic speeds before the prop tips reach 700+ mph.
Interesting stuff, thanks for all the education you folks have given me. You all have done a fine job of answering my question. I'm a little sharper now because of it.