It's a russian torpedo boat engine Zvezda M 503 A from the sixties but produced to date. They were used e.g. for east german "Projekt 205"- and "Projekt 206"- speedboats of GDR's Volksmarine until 1989. The Dragon Fire- TP- Team converted this big rig from a diesel into a menthanol- fired gasoline engine. Zvezda of St. Petersburg even built bigger ones, up to 2x 56 pistons for ships and power plants.
no, they just use "old" russian engines with 1500 hp each, the dragon fire torpedo boat engine is rated between 8000 and 10000 hp. Stronger turbines would be more expensive (if youd take 4 t407´s with 7500 hp each the other tractor could say goodbye) also grip is an important factor
Irrelevant, Dragon Fire runs like shit the majority of the time, that engine is supposed to power a tug boat, not be put in a drag rail and shoot down rail at over 100 mph, it's not tuned for it.