If you make your own, you will
be controlling the overlap and the closing point. So the Pport will be as
tractable as you make it.

Thanks for the info Lynn.  I knew I could count on you to get me thinking about this again.  For the record, I don't think I'd consider this for the RV-3 engine, because I don't want to make a long drawn out project out of getting it back in the air, however I am considering it for the single rotor. 

I guess my biggest question is what the benefit would be for us.  If we shoot for making top power in the "low" 7000-7500 rpm range, will we gain anything from the PP configuration?  In other words, if you compare a street port, to a tamed PP at 7500 rpm, will there be significantly more power with the PP?