Nick,
I’ve got a Lancair 320 with the IO-320-D1B 160hp engine and
the Hartzell 70” prop that Lancair and Hartzell approved for this airframe and
engine. I’m very pleased with the performance. A friend of mine
has the same airframe and engine as I do but has the MT 3-blade prop.
When we fly formation at exactly the same power settings, I am pulling away
from him at about 3-4kts. We haven’t tried a side-by-side climb
comparison but the 2-blade Hartzell is definitely a bit faster in cruise than
the 3-blade Hartzell, just as prop theory would suggest.
When I built the plane I was concerned about spinner wobble
and stresses, so I created a little donut inside the spinner that fits snugly
around the prop hub. You can see a photo of it here: http://lancair.net/pix/olsen/olsen-construction.
After 720hrs on the airplane I have had no problems with spinner or
cracking.
Cheers!
Dan Olsen
Fort Collins, CO
N320DK, 320 MKII, 720hrs
N630DK, IV-P, 20% complete