Professional Machinists Hate This Valve Seal Hack!

Why do mechanics use a power drill to cut their cylinder heads?! 🚀⚙️
When rebuilding an engine for high horsepower, mechanics often install high-lift camshafts and heavy-duty dual valve springs. However, the factory cast iron valve guides are usually too thick to fit the upgraded aftermarket valve stem seals!
In this highly controversial shop video, a mechanic decides to bypass the professional machine shop and do the custom fabrication himself! He chucks a specialized guide cutter directly into a standard hand drill and aggressively shaves down the raw cast iron valve guides! After blowing the massive pile of metal shavings everywhere with compressed air, he oils the freshly machined metal and snaps the new blue seal perfectly into place! Watch until the very end to find out the fatal mistake that will instantly destroy this engine on startup!