Yeah.  Also, I believe Tracy has answered all of his "questions" around tortionals and props and dynos.  Additionally, if there were problems, Tracy would have encountered one in 1500 hrs.

The guy's statement around "... sprag clutches cause the prop to freewheel in the event of engine failure putting the equivalent of a barn door (HUGE drag compared to stopped prop) behind the airplane ..." is so preposterous that it calls ALL of his other engineering into question.  His article sounds authoritative, but has all the intellectual allure of Lamar's rantings that NACA ducts and Electric Water Pumps "... cannot possibly work ...".  Stick with Tracy.  He has something flying.  This guy has nada.

Just a theory .... Jim S.

David Leonard wrote:

Yes, you should read Tracy’s discussion.  Also remember that the author of the post you sent was trying to sell the Powersport PSRU (for $6000 I might add).  Interesting also that to my knowledge the PSRU that has truly failed were the early Powersport PSRU. 

“Bill” implies that because the rotaries pulse is different from other engines it is somehow more damaging.  The reality is that the pulse from the rotary is must softer and lasts for a longer angular portion of the rotation of the e-shaft.  This makes the rotary much easier on  a PSRU than a 4cylinder piston.

I suspect (thought I have no evidence) that Powersport neglected to counterbalance their engine in the early testing that “Bill” mentions.

Dave Leonard