It sounds like the mains or rods ate the big one.

I know you feel like they should rebuild it since they messed it up, but if they didn't do it right the first time will they do it right next time or just slap a patch on it.

It needs torn down, meticulously cleaned, and all new bearings, including cam bearings. The bores are probably OK but I wouldn't reuse the rings. You will need to clean all the rocker shaft components and the shafts just in case any of that brass made it into those areas.

If they are telling you to run it a little more then I doubt they will take the time to clean it well enough and replace all the parts that may have embedded particles in them.



Sorry for the trouble.

Hope they make it right.