Hot Water posted:PRR 5841 posted:Stuart posted:I had heard that NS was going to do a rebuild on the SD80MAC's, but I didn't expect them to keep the V20 prime mover.
That is a surprise to me as well. If they retain their original V20’s, do they have be modified to meet Tier-4 or are they exempted?
Exempted.
Has anyone been able to meet T4 using a 2-cycle?
Yes, the marine industry simply loves the 710 engine in 12 cylinders, 16 cylinders, and even 20 cylinders.
If so, was it accomplished using urea/ionized water injection (Blue TEC) or EGR?
Almost 20 years ago, the railroad industry took a stand against the use on DEF (urea) in railroad locomotives. Thus, in order to comply with the T4 "requirements", varies forms of Exhaust Gas Recirculation had to be used by Progress Rail (EMD). As a result, the fuel economy went directly into the toilet! The marine industry, embraced the DEF additive, and are now using many, MANY 710 2-Stroke Cycle engines, with their longevity, reliability, and ease of maintenance/overhaul.
It is now beginning to look like the U.S. railroad industry made a very bad decision concerning the use of DEF.
I read years ago that while EGR will enable a 4-cycle to meet T4 standards, it often requires cleaning to ensure proper operation, not sure if this is still the case. I also understand that no one has been able to achieve T4 using EGR on a 2-cycle which is why EMD(?) could only make international deliveries for at least a year. Why the industry took such a hard stand against DEF especially considering the low cost that would have been realized once they started making it in-house is beyond me. Looks like the marine industry made the best call.
Dan, thanks for the great pics and sorry for the thread-drift.
