I've been digging around for more info on the Loncin X 18 engine and haven't come across much in the way of specs. Things like general dimensions aren't very well documented, at least from what I can find online. One thing I'm especially curious about is interchangeability. For example, does the X 18 head swap over cleanly with a Lifan head, or are there differences in the design that make that a no go? If anyone here has torn one down or experimented with mixing parts between Loncin and Lifan engines, I'd love to hear what you ran into, think its just easier to learn from someone else's wrenching than trial and error