George, Atkins is now using the Powersport internal ring gear psru. You
can check it out on the web at
www.powersportaviation.com . It's
a really nice unit though heavy, around 60 pounds. I do like the
arrangement in some ways. But it is high priced at $6,500.00! If I spend this
much on a PSRU I would buy the Mistral. Lighter and configured for a hydraulic
constant speed from the start. I had been in communication with the designer
of the PowerSport unit for some time. He was supposed to be building a new
unit that would handle more power and be lighter. He was involved in auto work
though and hasn't made much progress in over a year. The one big advantage of
the internal ring gear unit is that it offsets the e-shaft centerlind about 3
inches lower. That lower e-shaft center line makes it much easier to wrap the
intake over the engine. PowerSport has had some money problems so I don't know
what the current status of the company is. If I was to order from them I would
probably request a escrow account to prevent getting into trouble.