Chapter 3
Raw Power » Spark of Destruction

he plugs inside your car fire a charge hot enough to wear away metal. Here's how to re-create that process, only bigger A spark plug is one of those humble, anonymous things without which the world would grind-or rather coast-to a halt. And like many underappreciated cogs in the machine, it has a really hard life.

A good modern plug will endure 300 million sparks (around 20 per second) over 100,000 miles, each one triggering an explosion around its head as the fuel combusts, driving the engine's pistons (and thus, your car). But the spark itself is far more destructive than the bang. Cylinders, pistons and valve heads made of steel easily withstand the explosive abuse, but spark plugs made of steel would last just about long enough to get your car to the shop to buy new spark plugs.