Engine vibration is a very subjective thing. What one person might find very concerning may be ignored by someone else.
C-series Continentals do not have any dynamic balancing counterweights, so they're going to vibrate some no mater what you do. Most excessive vibration can be traced to something touching the engine or exhaust that shouldn't be, like cowlings. I personally would not spend a penny on dynamic prop balancing until I was sure the prop was statically balanced and the ignition system and valve train were both in top shape. John Cooper Skyport Services 4996 Delaware Tnpk Rensselaerville, NY 12147 518 797-3064 www.skyportservices.net ._,___
