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