CONCORD, N.C. — Kurt Busch’s moonlighting gig at Indy was a smashing success. His day job in NASCAR was a bust courtesy of a blown engine, sending his bid to complete “The Double” up in smoke.

Busch was game for completing all 1,100 miles of the Indianapolis 500 and Coca-Cola 600 in the same day. His desire willing but his car parts weak, Busch’s run at racing history ended late Sunday night not because of a wreck or weather, but a faulty engine that left his No. 41 Chevrolet a smoky, steaming mess.

Months spent training like a cadet and crisscrossing the country for the doubleheader ended in an empty garage at Charlotte Motor Speedway. His race came to a halt about six hours after Busch starred in Indianapolis, driving his backup car to a sensational sixth-place finish.

“I can’t let what happened here dampen the mood on what happened up in Indianapolis,” he said.

Busch completed about 907 miles in his quest to join Tony Stewart as the only other driver to complete the back-to-back races. “The Double” has been attempted by just three drivers, the last being Robby Gordon in 2004. Only Stewart in 2001 successfully completed the two races, finishing sixth at Indy and third at Charlotte Motor Speedway.