Federal-Mogul Corporation’s Powertrain Segment has introduced a new high performance spark plug to address increasing thermal and voltage demands of high-output gasoline engines.
Called SureFire Plus, the new spark plug technology delivers higher voltages, extends plug life and packages efficiently into the crowded cylinder heads of multi-valve downsized engines.
SureFire Plus is a step change technology, derived from the company’s SureFire plug launched in 2008. Advanced ceramic insulator materials enable SureFire Plus plugs to deliver voltages of 42kV or more, compared to 36kV previously.
Higher spark voltages permit the use of leaner fuel mixtures, enabling increased engine performance and/or better fuel economy while reducing CO2 emissions. The improved ceramic performance also enables a reduction in the size of the spark plug, from 14mm down to 12mm or 10mm, according to customer requirements.
“The ceramic insulator is the only barrier between the electrodes. It forces the spark to jump the gap, which initiates combustion,” explained Rich Keller, director of product ignition engineering, Bearings & Ignition, Federal-Mogul Powertrain. “The unprecedented level of ceramic performance we have achieved in SureFire Plus spark plugs enables a new generation of ignition systems that provide greater energy and durability in a smaller package.”
Spark plug insulators are typically composed of 95 percent alumina (aluminium oxide), with the balance in glass, which aids in manufacturability but limits the electrical and mechanical properties. The SureFire Plus insulator is made with a formulation containing a significantly higher percentage of alumina, with the remaining content a combination of various oxides engineered to optimize high temperature shunt resistance, helping to minimize the electrical current leakage through the ceramic. To address this change in material composition, Federal-Mogul is using new manufacturing processing equipment that achieves the industry’s highest ceramic formula compaction pressures during the molding process.
Higher Voltage The trends in modern gasoline engines towards lower CO2 emissions with increased performance and longer life are possible due to advances in component technology. Critical among these is the spark plug. Downsized, highly boosted engines produce much higher peak temperatures and pressures during the combustion process, while leaner mixtures and alternative fuels are more difficult to ignite. All these factors increase the energy requirement, and hence the voltage needed, across the spark plug.
Smaller Packaging Downsized engines mean smaller cylinders, often with four valves where once there were two. Direct injection engines must also accommodate the fuel injector within the combustion chamber, while increased power output requires more space for the coolant passages. These factors combine to limit the diameter of the spark plug, making the insulator thinner in cross section and increasing the risk of electrical breakdown.
ge breakdown was a vital first step, but to make SureFire Plus a production reality required a development breakthrough in compaction process technology,” said Keller. “That’s how Federal-Mogul maintains its technical lead; by combining cutting edge materials research with advanced manufacturing techniques.”
The first series production of SureFire Plus is scheduled for May 2014. The new patent pending material is also expected to have an impact outside the automotive sector, in applications such as the heavy gasoline engine market.
Federal-Mogul will present SureFire Plus ignition technology at the IAA Show in Frankfurt from September 10-13, 2013.
