Thanks for this one. A lot of good info in there. The engine is more different from NASCAR than I thought it would be. They have a unique block casting that has a traditional small-block Chevy head bolt pattern, but a .7" lower deck height, and cast from compacted graphite iron, which must have been pricey to source in low volume.
I wondered why he was talking about fuel washing the cylinder walls early in the video, thinking that it shouldn't be a problem with EFI. But it made more sense when I saw that they have the injectors above the butterflies in the intake manifold, and that they run E85 fuel. At low throttle openings, the injectors will spray the fuel on the throttle plates, which will run down the walls of the intake ports, and give poor atomization and mixture distribution. Since it's a race engine, and spends maybe 70% of its time at WOT, maybe that's OK, but I'd like to see results of a post-race UOA that shows fuel dilution. I bet it's bad. If they had a second set of injectors below the throttle plates, and switched to them below "X" throttle opening, they could eliminate the fuel wash issue, and probably save a lot of fuel over race distances. Or do the rules prohibit a second set of injectors?