I think it would do better than 18,000 for sure thinking 19,500 or so. i will have to run one to see. two Jetts best engines are the 35 and the 56
Here is a video of my Jett 35. I didnt know i was being filmed this time. Never do what i did and run up the engine while in the prop arc.
http://www.youtube.com/watch?v=jYFfBags08M