During IndyCar warm-up on Sunday in Detroit, Chevrolet General Motors president Mark Reuss confirmed the root cause of the issue behind a rash of engine changes in the IndyCar garage.
"We had a supplier issue with the valve and the valve guide, and it's a coating issue," Reuss told IndyCar on FOX. "And so if you can imagine the valve sitting in the guide with the wrong coating, over time, you get to see the valve chuck off the seat. And so, it becomes fatigued. It doesn't happen on every engine, but we had a lot that didn't have the coating, so what we're doing is we're going in and changing those coatings and valves to make sure we run as reliable as we have since 2012.
