I've been hearing good things about Balance Masters Active Balancers for aircraft engines. I called up the owner and had a great conversation about the options I had with this UL Engine and we concluded that the Cessna model would fit well. For only $170 I thought I'd give it a try. She was drilled to very tight tolerances and fit extremely well to my SAE 2/5 Bolt Pattern. Taking her for a flight was interesting. I previously had some annoying vibration around certain RPM ranges and especially on climb out. After installing the Balancer, there was a noticeable improvement on all RPM's above 1700, so I say it's a success and should help keep things smooth during breakin. :) On an important side note, I also switched to a NON AD, mineral oil to speed up the breakin, so naturally my temps went up, negating the ability to see if the Cylinder plenum honeycomb was affective at reducing temps. I found that the temp spreads had not changed, however, so changes to the baffling is unavoidable. Not a big deal just a little more glass work.
