Back to bikes stuff. Rebuilding a CB350 engine after a bit of a f**k up. Dropped the head of an exhaust valve with a bunch of revs (I found the valve head in the sump) and he has bought another engine for parts. Needed to get the rings off the stuffed piston to put on the replacement 2nd hand one (to suit the barrels from 2nd engine) but was unable to prize out the top ring after the top of the piston had been pounded by the valve head. I tried heat hoping that the alloy would expand enough to allow the ring to push out, no good. Got the Dremel and with a tapered cutter cut away the metal above the ring. I was then able to get a small flat blade screwdriver and break away the alloy above the ring to release it. Cleaned up and fitted to piston and barrels on.