Tom Wiliams wrote:
"I have a friend with a 320 which is tail heavy. Can’t have 2 people or full fuel without going out of aft CG. I remember someone talking about a harmonic balancer that was about 12 lbs and attached to the flywheel or spinner. That would help him a lot if I could find one. Any ideas???"
Tom: I have an "harmonic dampener" installed on my 360. It weighs exactly 17 pounds but one like it installed on your plane could easily weigh more or less - it should be sized to optimize your weight/balance requirements. If you use an hydraulic constant speed prop, this arrangement won't work for you; it does well on my 360 because I use a very light weight electric constant speed prop so I don't need oil pressure from the engine. (I use slip rings to transfer battery voltage to the prop.)
If you are currently using either a fixed-pitch or electric prop, perhaps you can have a balancer/dampener made for your plane and mount it directly to the prop flange. My dampener was made by a reputable local machine shop and it fit perfectly and tightly on the very first installation to my 360 (cost, $140.00). I now have 400 hours on it since initial installation and am very pleased. It also helps at engine start because its spinning mass helps to overcome compression resistance. Greg Nelson