Could someone please provide the horsepower and top speeds of each: the K4s Pacific, the H6a Consolidation, and the E3a Atlantic. I can't seem to find them anywhere. Thanks!
No one knows.
As for "top speed", you'd have to spell out what you mean-- not that any of us could answer even if you did. How fast could it go down a 2% grade without actually flying to pieces-- that's one possible definition, but other definitions are reasonable too.
They did put the K4s on the Altoona test plant-- they originally claimed 3184 maximum cylinder horsepower, which presumably was with hand firing. The 5399 did better, of course, and Railway Age gave road-test horsepowers for it and a conventional K4. As I recall the conventional peaked around 2500 dbhp.