SD40, SD90… it's hard to keep those off-brand locomotives straight! Yes, that's probably what I was remembering. Thank you for the details and link!
The engine is… different. The 16-cylinder QSK is rated at 4400 horsepower (hmm… wonder how they chose that output to aim for (Grin!)), but the cylinder volume is only about half that of an FDL. Top speed is 1800rpm, instead of the ?? 1050 ?? rpm of the FDL. So it's probably smaller and lighter in weight than a standard U.S.-style locomotive prime mover, which is good for the niche market of high speed passenger units. But my impression is that the larger cylinders of the bigger engines make for better fuel economy (better volume to surface area ratio, so less energy lost through the cylinder walls), and the lower rpm of "medium speed" diesel engines reduces wear and tear and so makes them less maintenance intensive. Does anybody here know how the QSK compares in fuel efficiency and (predicted) frequency-of-repair to engines like the FDL (with the GEVO being superior to the FDL on the first and I would suspect the second count)? Unless Cummins can match the competition on these fronts, I would think they would have a hard time penetrating the freight locomotive market.
(Oh. I think something I read suggested that the QSK engine uses Urea to achieve Tier 4 emissions standards: something very unpopular with large freight railroads, and that GE put a lot of work into avoiding with the Tier 4 GEVO. I don't understand Cummins's strategy.)