The design of spark plugs, critical for igniting the gas mixture in the combustion chamber, must catch up with the latest advances in automotive engine development because many improvements for higher efficiency and lower emissions make combustion more difficult to initiate. Spark plugs must maintain their function in both below freezing environments and high speed, high temperature operation.
The performance of a spark plug is characterized by the shape of its firing end exposed in the combustion chamber and the layout of the insulator nose in the metal shell.
This paper summarizes recent requirements for spark plugs, proposes a new firing end shape, and evaluates its performance. The relationship between geometric configuration and performance are evaluated on an actual engine.
The results demonstrate improved spark plug performance, especially under the most extreme temperature conditions.