Hartzell Composite BA Question

Hello all,
No luck in the searching I have done regarding my question. So I have ordered my AeroSport Power IO-375 at OSH this year. I wont be able to get the prop until next summer so I will be fitting the cowl using the spacer method. So I have the info from the FAQ on Vans website that says use 2 1/4" for FP and 2 1/8" for the CS. Does this measurement work for the "G" hub that is now required for those blades (N7605P)? Matt from Hartzell emailed that the distance from the engine flange to the spinner bulkhead is 2.25" which doesnt include the ring gear. Have any of you used the spacer method before using this prop or used it for another prop and changed to this prop? Thocker? Kahuna?

Thanks for any info!

On my RV8 I used 2 1/4 spacers on top of the ring gear and between the Vans spinner bulkhead. That was for my original blended airfoil aluminum prop. I then used a 3/16 spacer between the cowl and spinner back plate. So, I had a 3/16s gap with my original prop. With the G hub I now have about a 1/4 inch gap. I could move the spinner back plate back via spacers if I wasn't so lazy. There is plenty of adjustment range with the Hartzell composite and the Hartzell spinner, the spinner has no filler plate so adjusting it later is easy.

Thanks Jon!

Thats just what I wanted to hear! Getting everyting lined up so when I'm done with the buid school and have the engine I can start rolling!

I'll check what hub I have, but the composite Hartzell blade is quite wide and at full pitch it comes back farther than the aluminum BA. You should get the dimension from Hartzell for that. Use the attachment flange face interface as datum. This will ensure that the prop won't be too close to the cowl when at full pitch. Remember that the engine is rotated and not pointed straight. It is at an angle to the fuse axis, so the right side may be closer than the left unless the cowl inlets are also staggered.

Definitely get the Hartzell spinner, I wanted to save money and used the Vans. It required modification of the cowl. You will not like that.

Thanks Bill

I did get an answer on that front from Hartzell. The "G" moved the prop blades forward 1" due to blades coming in contact with the cowl when using the "C" hub.
Michael

ConAgraPilot said:

I did get an answer on that front from Hartzell. The "G" moved the prop blades forward 1" due to blades coming in contact with the cowl when using the "C" hub.
Michael

Click to expand...

Here is a thread on some clearance discussions. I added some dimensions for the "C" hub. I was/am using the SJ cowl and a 2.5" spacer. Not down in about post #17 a clearance with the Vans cowl, indicating the full pitch should be no problem. Extending the nose flange is not trivial for 5/8" so if the Hartzell spinner fits better than the Vans, I would highly recommend it. Especially if there is some adjustment fore/aft. All my work was done with the flywheel on as that is the way it will be assembled.

Some other good comments in that thread too. I was always a little concerned the composite would give up some efficiency at full power/rpm but later documented testing showed it is equal to better. It is about 100# greater thrust over the aluminum up until HP limit is reached.

I just took my plane to the airport, so shall report actual feel later. I am super happy with my choice already.

BTW - there are some G limit discussions with the "G"-hub and/or spacers, but that is another topic.