How Mechanics Trap Engine Explosions!

What is this mechanic doing with a suction cup?! 🧐⚙️ If engine valves don't seal perfectly against the cylinder head, explosive pressure escapes and you lose all your horsepower! To guarantee a flawless fit, mechanics use a process called "valve lapping." They apply a gritty abrasive paste, grab the flat valve face with a rubber suction cup, and rapidly spin it back and forth by hand! This custom-grinds the two pieces of metal together until they match perfectly!