Has anyone ever used stock valves, with adhesive sandpaper, as fly cutting tools? Even though the valve might be too small, it's seems that with the valve angle and piston travel, if you cut at TDC you would have enough clearance both laterally and vertically.

 

That would be a VERY bad idea. The possibility of getting the abrasive from the sanpaper into the engine is scary.

 

Just buy the tool.