----------------------------------------------------------
                           RV10-List Digest Archive
                                      ---
                     Total Messages Posted Tue 01/25/05: 1
           ----------------------------------------------------------
 
 
Today's Message Index:
----------------------
 
     1. 08:05 AM - Re: RV10-List Digest: 4 Msgs - 01/24/05  (LessDragProd@aol.com)
 
 
 
________________________________  Message 1  _____________________________________


Time: 08:05:48 AM PST US
From: LessDragProd@aol.com
Subject: RV10-List: Re: RV10-List Digest: 4 Msgs - 01/24/05

--> RV10-List message posted by: LessDragProd@aol.com


Hi Al,

One of the reasons I like working will MT Propeller is that they seem to  
have a better business ethic than our own American propeller  manufacturers.

Regards,
Jim Ayers

In a message dated 01/24/2005 11:59:22 PM Pacific Standard Time,  
rv10-list-digest@matronics.com writes:

Time:  08:41:35 AM PST US
From: AI Nut <ainut@hiwaay.net>
Subject: Re:  RV10-List: Lycoming - tractor engine or turbine smooth?

-->  RV10-List message posted by: AI Nut <ainut@hiwaay.net>

It may be  smoother, but I'm told by prop manufacturers that one will 
lose a few kts  in cruise with a 3-blade.  I opted for  smoother.

David


LessDragProd@aol.com  wrote:

>--> RV10-List message posted by:  LessDragProd@aol.com
>
>Lycoming - tractor engine or turbine  smooth?
>
>This is the real question that needs to be asked when  you are considering  
>which propeller to buy.
>
>I had  an opportunity to test four different constant speed propellers on   
one

>aircraft.  There were three different 2 blade propellers  and one 3  blade 
>propeller.  This aircraft was owned by a  friend who flew the  aircraft.  I 
just

>went along as the  observer and data recorder.
>
>The original CS propeller on the  aircraft had been dynamically  balanced on 
>the engine.   Since the plan was to leave the original propeller  on the  
>aircraft when we were finished with the testing, we did not removed  the  
dynamic

>balance weights from the engine ring  gear.
>
>All three of the 2 blade propellers had about the same  vibration level  
>during their flights.
>
>Then we  flew the 3 blade propeller.  On the takeoff roll and  initial 
climb,  
>I noticed the pilot was highly stressed about something.    About mid field, 
as

>we were climbing out, he finally said that  something must be  wrong with 
the 
>engine.  That the engine  wasn't producing power.
>
>We laughed about this  later.
>
>We seem to expect a certain vibration level which can be  directly related  
to

>the engine power.  We don't even  think about this.  And it's not  something 
>that any  instructor I have had has ever talked about.  It's just   there.
>
>I've been told that a 2 blade propeller has a 2nd order  harmonic on the  
>Lycoming engine.
>
>And the 3 blade  propeller does not have the 2nd order harmonic on the  
>Lycoming  engine.
>
>What does this really mean?
>
>On another  test sequence, I had an opportunity to again ride in a friends   
>aircraft.  On this friends Harmon Rocket 2 with a stock  Lycoming  
IO-540-C4B5,

>we removed a 2 blade propeller and  installed a 3 blade  propeller.
>The 3 blade propeller made the  Lycoming run like it was an electric motor,  
>it was so vibration  free.
>When we install a second 2 blade propeller, the same old  vibration came  
>right back.  At the same level as the first  2 blade propeller.
>
>So the question goes back to you, the  builder/flyers.  Do you want  
"turbine 
>smooth" or "tractor  engine"?
>
>Regards,
>Jim Ayers