First race with the new bodies. For best speed on the long tracks, teams want to minimize the openings in the nose for cooling radiator, oil cooler, and brakes. Probably didn't have the openings big enough, or in the right location, to get the best airflow. Also possible they had switched suppliers for something like valvesprings or whatever, that proved not up to the task.

The mark has a reputation for starting preductably everytime. So they fail predictably everytime. Reminded of the old Chevy 409s of 50 yrs ago: Got out front before blowing due to inadequate cooling (water jacket?). But they failed much more quickly.

Engines like this are assembled by basically one person.

I'll bet all three were done by the same guy, thus three similar failures.

The rebuilder screwed up something. And I'll bet he knows exactly what it was by now.