I have a Doylejet - Dynajet specs - plus a Maxjet 15, not sure if I have the only one they sold or not. I believe it is 90mm, I should go measure it. This is the static test they had posted on the website at the time:

http://www.truerc.net/jetengine.avi


And I am pretty sure it was these guys that made it. Lost all the docs a while ago. It was on the treuRC website for a while but not now, although the video link above seems to still be active.

https://www.youtube.com/watch?featur...&v=DnAnx0R8VcQ