Ron,

I have been looking for any infomation on the XYZ engines I could find. I came across a supplier in China that has posted on there site comments from customers who have used the XYZ 50. One of the customer posted he is getting 8000RPM with a Xoar 18x8 prop. So it looks like this XYZ 50 engine of yours is going to be the ticket for many a RC Flyer. If you lose on the average of 500RPM for every 2 " you go up in prop size and keep the pitch the same. That means the XYZ 50 should spin a Xoar 22x8 prop very close to 7000RPM. That is very good in my books.

I am now really looking forward in getting my hands on this engine.