Engineers from Fiat Chrysler, Mexican engine parts supplier Nemak and the U.S. government's Oak Ridge National Laboratory have jointly developed a blend of aluminum alloy for cylinder blocks and heads that raises the heat threshold they can withstand from 390 degrees currently to about 572 degrees.
Hotter running engines are expected to deliver big gains in fuel economy and emissions, and FCA is evaluating the alloy to use in upcoming cylinder heads.
"Cylinder head alloys are the most demanding application in an engine, if you consider the fact that the casting is smaller than the block — but more complex because other parts are attached to it," says Amit Shyam, Oak Ridge's lead researcher on the project. "It's more demanding from a thermal-mechanical aspect as well. The head sees many thermal cycles. If that was solved, it would be a very major advancement for better engine materials. That's why we focused on cylinder head alloys for initially lighter-duty automotive engines."
Hotter-running internal combustion engines are a critical area of interest for the industry in the next decade. Despite efforts to roll back federal fuel economy standards, the targets set by the Obama administration stand, and automakers are still sprinting to meet them. Improved thermal efficiency will likely be an area of competitive focus. The less heat an engine wastes, the more efficiently it runs. Toyota has recently made big gains in improving thermal efficiency, bumping the Corolla's engine to 40 percent.