If you want to try out someone else's solution....

https://www.rcgroups.com/forums/showthread.php?1862693-OS-46FX-rebuild-with-ASP-46-piston-and-liner-SUCCESS-!!!

Dave

If you want a "brick and mortar" solution, then it's likely the ship has sailed. But the one good thing about the internet is that it can connect the one guy that has the last one (or two) of a thing to the last guy that wants that thing and no other will do.  Think of it as internationalizing the auto dismantler's job. No fabulous memory required, no "gotta know a guy," no (or at least less) highway robbery for the last of the last--when it isn't.

What I can't tell you off the top is whether the AX and FX P/L is interchangeable or not. Or, if you'd be happy with the P/L from the heli version of the FX, which has a ring.

I think the MECOA .46 Aero CL might be a near-clone of the OS .46SF, which makes it doubtful it'd go into a OS FX

But if you aren't into the treasure hunt, then you need to change your engine acquisition strategy--or buy a machine shop.

Finally, I suspect that the OS .46FX when wide open is a honkin' motor that would require setup strategies to make it suitable for control line sport/stunt. Like maybe a pipe? Maybe a vesspucci around .253" like comes with the MECOA?

Dave

PS--Just as a footnote, and I think we've talked about this before, I have an OS .46LA that peeled a liner. Not too close to the top. No need to go back into all the controversy about the if's, how's, and why's, but what I did when I found it but still wanted to fly, I went in and very, very gently cleaned up that area of the liner and the surface damage to the piston. And ran the engine for quite a while after that. Yes, the compression was down. Yes, the power was down some. But it still had enough to fly a profile Cardinal nicely. But there were no delusions that it was repaired--just returned to service.