Dynamic Prop Balance

[jazztheglass]

I am having the engine in my 1970 M20C overhauled.  It should be ready next week.  The prop got resealed (its less than 5 years and 1000 hours since new).  When would you guys recommend dynamic prop balance during the break in period?  Also does anyone have a recommendation to do dynamic prop balancing in Kentucky?

 

[Hank]

Yes, i would recommend it. The previous owner had mine done while overhauling the engine at Signature in/near Cincinnati, I believe.

Because it was so long ago (2003), I had it checked at my last annual: 0.01 ips. We left it alone. FYI, it's the offen maligned Hartzell 3-blade that is supposed to vibrate madly on a 4-cylinder Lycoming.  

[Tommy]

Definitely worthwhile doing it but probably after the engine had broken in because the whole ordeal is a bit of trial and error and your engine will be running at low power setting during the process. 

Also if there is anything needs to be adjusted the balance might be out again. 

Edited October 15, 2017 by Tommy

[mike_elliott]

9 hours ago, jazztheglass said:

I am having the engine in my 1970 M20C overhauled.  It should be ready next week.  The prop got resealed (its less than 5 years and 1000 hours since new).  When would you guys recommend dynamic prop balance during the break in period?  Also does anyone have a recommendation to do dynamic prop balancing in Kentucky?

 

I have used Aircraft specialist in Jeffersonville, In KJVY before and was very happy. http://chooseasipropellers.com/  They, also like Hartzell in Piqua, got a 3 blade I had hanging off my F to within .01ips like Hanks, but that thing still made the plane shake like one of the bulls I saw at the rodeo in Boerne Tx last night. Off came the 3 blade and a new 2 blade went on. Perhaps if I never had a 2 blade on the plane in the first place I wouldnt have known it to be a shaker when the 3 blade was put on. I only tried the 3 blade because at the time, they were cheaper, and when I proactively sent my 2 blade to Piqua for OH, they declared it dead.

True story, Don Maxwell had a 4 cyl C owner who swore how smooth his 3 blade was. Don convinced him to let his guys hang a 2 blade on it while they went to lunch and try it. He ordered a 2 blade after he flew that configuration that afternoon. Sometimes its not what you dont know, but what you know that isnt so.

[Andy95W]

1 hour ago, Tommy said:

Definitely worthwhile doing it but probably after the engine had broken in because the whole ordeal is a bit of trial and error and your engine will be running at low power setting during the process. 

Also if there is anything needs to be adjusted the balance might be out again. 

Good advice, IMO.

[jdrake]

+1 for waiting for the engine to break in.  You'll be running at various power settings as well as waiting for rings to seat.  I waited about 100 hours post overhaul and couldn't be happier.

[FoxMike]

After engine  overhaul I waited about 50 hours before prop balance to give the bearings and other internal parts a chance to wear in.