The secret to maximum compression

Why are mechanics rubbing engine valves with a wooden stick?! 🚀⚙️
Over time, the extreme heat and pressure inside an engine can cause the metal valves to warp or build up hard carbon, preventing them from sealing correctly! If the valves don't seal perfectly against the cylinder head, the engine will lose compression and massive amounts of horsepower! If left unfixed, hot exhaust gases can actually melt the valve and destroy your engine!
To prevent this, professional engine builders perform a highly precise "valve job"! In this satisfying video, the machinist first uses a specialized stone grinder to recut the metal valve seat perfectly round! Then, they apply a special grinding compound and use a manual lapping stick with a suction cup to perfectly mate the new valve to the seat! By spinning the valve back and forth against the abrasive paste, it creates a flawless, airtight metal-on-metal seal for maximum engine compression! Huge respect to the machinists keeping these motors running strong!