Why do spark plugs have different tip shapes and what are the differences?

Spark plugs are necessary for gas-powered engines. However, they're not all the same, and they can come in different shapes ...
Hot Rod

Does Side-Gapping Spark Plugs Work?

This is an extreme Champion racing spark plug once used in 15:1 NASCAR superspeedway motors with a radically cut-back side electrode. Spark plug manufacturers usually spot-weld side electrodes to the ...