Valve springs are among the most highly abused components in a modern engine, road or racing. See what happens when they fail in this fascinating ultra-high speed video. 

In this intriguing but disturbing super-slow-motion study of an automotive valve spring at work, we can see a number of things happening, nearly all of them bad. From the beginning, we find the spring suffering severe surge and undamped oscillation. By around the 22-second mark, the valve stem itself is wobbling around and flexing in the valve guide in an alarming way. At 32 seconds in, the valve spring’s inner damper is clearly fractured in at least two pieces, and at 1:42, the primary outer spring snaps, giving up the ghost completely. Ouch. Game over.

When this failure occurs in oh, say, a NASCAR V8 at 9,000+ rpm, the engine develops a severe miss and total, catastrophic engine failure can be expected to follow soon, very soon. Modern valve springs can handle a tremendous amount of stress and abuse, but when they aren’t happy, the engine won’t be happy for long, either.

In fact, valvetrain and valve spring dynamics tend to be critical in many engines, which is why the wizards at Performance Trends, Inc. kindly offered this revealing video, which we share here. The Livonia, Michigan company offers a complete line of hardware and software analytical tools, including its powerful Engine Analyzer Pro software package, which in the Enterprise Edition includes valve spring analysis. This extreme slow-motion photography provides an excellent illustration of just what valve springs—and valve spring designers—are up against. Video below.