Don’t flinch!

What is the secret to building a reliable, high-horsepower engine?! 🚀⚙️
Inside a fresh cylinder head, massive steel valve springs are constantly under extreme pressure. They are responsible for snapping the valves shut thousands of times per minute to seal the combustion chamber and maximize your horsepower. But the only thing keeping these heavy springs attached to the valve stem are two microscopic metal wedges called "keepers" or "locks"!
In this incredibly satisfying professional engine assembly video, a mechanic uses a specialized overhead compression tool to safely push down the heavy steel spring retainer! While the spring is fully compressed, they carefully place the two tiny metal keepers directly into the machined grooves on the valve stem! When the tool is released, the spring pressure locks the wedges perfectly into place! Watch until the very end to find out what happens if these tiny locks fail at high RPMs!