In order for any internal combustion engine to function properly, you need three basic things: air, fuel, and spark. Air mixes with the fuel, providing an explosive catalyst. The engine compresses the ...

If you've ever seen a mechanic draw a tiny line on a spark plug before changing it, they're not performing witchcraft — they're indexing it. The idea is simple. Most standard types of spark plugs have ...

Spark plug indexing sometimes is necessary to avoid side-electrode contact with high-dome pistons. Moroso offers different thickness spark plug washer kits to do this. Some theorists claim positioning ...