On Apr 6, 2005, at 9:53 PM, mquinns@aol.com wrote:

Lorn,
   I am considering props for my 360 and was told you have an Aerocomposites prop on your 320 (360?).

Yes.

Could you tell me if your aircraft uses the long engine mount or short?

Short.

Does the prop spinner require modifications to the cowl?

No.

Is the prop 68 inch diameter?

According to Hartzell at

     http://www.hartzellpropellers.com/kitplane/index_kitplane.htm

you can see that the Lancair 320 is supposed to use the 70" prop. When I first talked to Aero Composites they asked me what diameter I wanted the prop to be. Apparently they had the ability to vary the diameter somewhat. We both agreed that 70" (the same size as the Hartzell) would be best. I got the impression, while talking to them, that a larger diameter is better, as long as the ground clearance is satisfactory.

Hartzell's sight for the 360 lists both 68" and 72" for the 180 hp and only a 72" for the 200 hp 360s. Take a look at the Aero Composites site at:

     http://www.aerocomposites.com/index.cfm?fuseaction=home.viewPage&page_id=E36FDA21-5004-D739-A5792799EC7B5445

for the model that is right for your plane and engine combination. With the Aero Composites prop and the 360 engine you can go with either 2 or 3 blades.

To not leave anyone out, there is also the Whirlwind Airboat Propeller Co. Whirlwind is starting to make aircraft propellers. They cost less and only weigh 28 lbs. I saw one at the KOBZ airport in Georgia. A current problem with their constant speed prop is that it has to go back to the factory every 250 hours for inspection. They should be better in the future.

     http://www.whirlwindaviation.com/

Do you have any advice after making the choice to go with this prop?

It is a great prop. I now have about 300 hours on the prop and my leading edge looks like new. It doesn't have one scratch on it. The nickel leading edge really works.

Were there any weight and balance issues caused by lower weight of the prop?

Originally my planes CG was to far aft. The lighter prop didn't help at all. I have solved the CG problem using 3 different techniques.

1) I have a "Harmonic Dampener" that weighs 12 lbs attached to my flywheel. This doesn't hurt at all. Scott Krueger also has one. Besides adding weight to the front of the plane, the dampener smoothes the engine. This additional weight moves the CG forward 1/2". If you are interested, they are made by:

     Mark Landoll
     1205 Red bud Lane
     Newcastle, OK 73065

     405-392-3847

I paid $387 for mine a couple of years ago.

2) I had my battery moved from behind the baggage compartment to behind the passenger seat.

3) I carry about 20 lbs of tools in front of the passengers feet.

My current CG is 58.6" behind the aft end of the propeller spinner.
This converts to 24.1" using the forward face of the firewall.
I am still pretty far aft.

Thanks for your help.

MARK QUINN

In summary, the Aero Composites prop is the best prop that I have ever flown behind. I believe that it has increased my top speed by about 5 knots. In the Redmond 2004 100 mile race, I came in first in the 320 class. In the Sun 'N Fun 2004 100 mile race, I came in second in the 320 class. To bad it was cancelled this year.

Good luck with your decision and feel free to call if there are any other questions or problems.

Sincerely,
Lorn
--
Lorn H. 'Feathers' Olsen, MAA, DynaComm, Corp.
248-345-0500, mailto:lorn@dynacomm.ws
LNC2, O-320-D1F, 1,000 hrs, N31161, Y47, SE Michigan