Modern turbocharged gasoline direct-injection engines place particularly high demands on their spark plugs’ resilience and reliability. Introducing the new Bosch EVO spark plug, a particularly robust spark plug engineered to reliably ensure a stable ignition throughout its long service live – even if it is subject to the extreme conditions it faces in modern engines. Thanks to its improved isolator design and its high dielectric strength increased to 45 kV, the new spark plugs even withstand events of irregular combustion – known as mega knocking – which can occur in modern highly developed engines.
EVO with laser-welded iridium pin on the center electrode
The new Bosch EVO spark plug was developed to ensure reliable ignition of turbocharged gasoline direct-injection engines. In order to make sure it copes with an increase of pressure as may occur in cases of mega knocking, it is particularly robust – thermomechanically, mechanically and electronically. The laser-welded iridium pin on the center electrode and a platinum plate on the ground electrode ensure its long service life and its high wear resistance. Featuring an improved isolator design, EVO spark plugs cope well with repeated removal and reinstallation. At their installation, the correct torque is to be observed under any circumstances. It ensures the spark plugs’ exact positioning and orientation within the combustion chamber. Bosch EVO spark plugs are to be produced at the Bosch plant in Bamberg, Germany. They will be available as of October this year and mark the beginning of a portfolio expansion. At a first step, EVO spark plugs will be launched for modern gasoline direct-injection engines of Volkswagen and Mercedes-Benz vehicles.
Different electrode alloys to meet the specific requirements of each engine
Depending on the type of engine, the demands modern engines place on spark plugs vary a lot. In close cooperation with the car manufacturers, Bosch thus develops original-equipment spark plugs geared to the specific requirements of each engine. For this purpose, Bosch engineers rely on comprehensive know-how and decades of experience in the fields of gasoline injection and ignition systems. Back in 1902, Bosch solved the issue related to the safe ignition of the air/fuel mixture by means of its first spark plug. Nowadays, Bosch offers matching spark plugs for series-production passenger cars, small engines and stationary gas engines. Lessons learned in motorsports and innovations produced for this purpose regularly influence both development and series production.
During spark plug production, for instance, Bosch uses different electrode alloys featuring different advantages – among other things – to meet the specific requirements of each engine. Special production techniques – such as a nickel-plating process for thread and housing developed by Bosch and also used for the new EVO spark plugs – ensure improved corrosion protection and a long service life.
SOURCE: Bosch
