A system for testing an insulative material for a spark plug comprises a test spark plug having at least a center electrode and an insulator comprised of an insulative material surrounding at least a portion of the center electrode, wherein the insulator has an end that is closed, whereby the closed end of the insulator encloses an end of the center electrode. The system may further include a test engine that simulates engine conditions, wherein a conventional spark plug is installed in a first ignition port of the test engine and the test spark plug is installed in a second ignition portion of the test engine and a control system for controlling ignition signals to the test spark plug and the conventional spark plug.