CHARLOTTE, N.C. -- Hendrick Motorsports officials say a bad batch of parts led to engine failures by Dale Earnhardt Jr. and Mark Martin in Sunday's Sprint Cup race at Auto Club Speedway in Fontana, Calif.
"Both cars had valve train failures that were related to a specific batch of parts from a vendor," said Doug Duchardt, HMS' vice president of development.
Duchardt said the parts were not restricted to use by Earnhardt and Martin, whose cars are prepared out of the same building. He said they also were used by Hendrick drivers Jeff Gordon and Jimmie Johnson, as well as lease programs such as Stewart-Haas Racing.
Earnhardt finished 39th and Martin 40th after both lost their engines within 25 laps of each other. Gordon finished second and Johnson was ninth, combining to lead 138 of 250 laps. Tony Stewart was eighth and led three laps.
"So we're glad it wasn't more widespread," Duchardt said.
HMS traditionally has one of the most dependable engine programs in the Cup series. Sunday's two engine failures equaled the total for the entire organization in 2008.
Earnhardt enters Sunday's race at Las Vegas Motor Speedway 35th in points with three races before the 2009 Top 35 is set. Martin is 27th.
"It's always extremely disappointing when something like that happens, but fortunately it's a problem we can quickly address and fix," Duchardt said. "Our engine team did a great job identifying the root cause, and it shouldn't affect us moving forward."
David Newton covers NASCAR for ESPN.com. He can be reached at email@example.com.