Some time ago I read an article by some one who saved clapped out liners by pressure squeezing the circumferance of a liner. Any body remeber this ?
I have heard of RC car guys doing something like that. I can't say I see any horrible problem with doing something like that, if done as they do (with a carefully-machined clamp for .0005" inch or so (which is all it should take)). Knowing stunt guys, no, you can't use vice-grips!
In any case, if it's worn out, you have nothing to lose.
I haven't known of anyone doing it to a stunt engine. Its also nearly impossible to wear out an AAC/ABC/ABN piston/liner in stunt, anyway, so you are likely to move on to the next big thing before you have to worry about it.
Brett