Question?
On my LNC2-360 (BIB plus high comp pistons) there is an add-on "balancer" bolted to the face of the starter ring gear.
It is supposed to balance the engine with its internal weights that are supposed to arrange themselves to cancel or dampen our any sensed vibrations.
The "balancer" is about 2 inches in debth and almost the diameter of the ring gear; it is all self contained and you would have to take the prop off to get it off and take it apart if one was at least currious what was inside of it.
 
It's difficult to know if a 4 cyclynder Lycoming is as smooth as it can be, because it's not a real smooth engine under the best of conditions.
 
I inquired to a local experienced prop balance person in Redmond and they concluded that because of the dynamic balancer on the ring gear, he would not attempt to balance the engine with his expensive balance work, as he thought the attached dynamic balancer would change the internal weight at will.
 
Does anyone have any experience with these dynamic balancers attached to the ring gear???
 
Cheers
 
Jack Addison  N360JS
near Redmond, OR