We have another wrinkle in the unfolding story of the 710ECO project:
According to Mr. Ken Lanovich of the LocoNotes group, the FRA blue card
inside the EMDX 7101 lists a model designation of
GP22ECO. So
now we have a conflict between what EMD calls it, what the person who
entered the unit into UMLER calls it, and what the person who filled out the
blue card calls it.
To respond to Mr. Hazen's remarks, I have never heard of a "straight six"
version of the 710 engine... but like you say, we could be surprised
tomorrow and find out that there are several examples of it in (for
instance) stationary or marine service. What I do know is that on EMD's
web page of products for stationary and marine service, they have never
listed a 6-710 on that page... but that doesn't
necessarily mean that
a 6-710 doesn't exist.
It was also mentioned on LocoNotes -- and this is still unconfirmed -- that
GE may be working on a "straight six" version of the GEVO, which would
have an output of 2250 HP. If I hear anything more about this (especially
if there's any evidence to back it up), I will post it in the GE forum.