SD70/SD90

[GDRMCo]

Being built still.

[D.Carleton]

Speaking of SD90s, what ever happened to the SD90MACs that Cummins was rebuilding with their new high-speed QSK engine?

[M10000]

 

 

 

[Leo_Ames]

It's only a 6' difference. With a more modern electronics package, they'd have a fighting chance. 

Without EPA interference, I'd have little doubt that it could be done. 

[YoHo1975]

The SD70ACe is I believe shorter than the 90 so no, you couldn't really fit the H engine and needed cooling. At least not a v16 H engine. Spotting differences between and HII 90MAC and a 70ACe are 70 is shorter...and that's the most obvious. The H2 had 2 large fan instead of 3. The newer cab style came with the H2. The 70ACe has the angled roof. The H1 had the older style EMD Wide nose cab and 3 fans as does the convertible 90/43

[NorthWest]

doug u

What do you mean the "phase ll" . Is this something that can be seen on the loco or is this something internal and cannot be seen

The differences are external. The cab is different (a lot like the SD70ACe cab), and the back end is tapered to a far greater degree.

doug u

I think that it is hard to see any differences between the SD90/43MAC (710 engine) and the new SD70MAC (they both use the 710 engine).

By looking at the radiators, you can tell an SD90MAC from an SD70MAC, from the cab you can tell an SD90MAC from an SD70ACe.

doug u

Is the "phase ll" applied to the SD90/43MAC

No. It was an attempt to salvage the SD90MAC-H, produced after the "convertibles".

doug u

Can they fit the H engine into the SD70MAC ? That would be a 6000 hp SD70MAC if it would fit.

Physically, probably yes. However, there would be inadequate radiator capacity, and it would not make the emissions standards. Plus,  there are the issues with the 265 and 6000HP locomotives in general.

[doug u]

NorthWest : the SD90MAC - H have the a 45 * angle on the longhood. What do you mean the "phase ll" . Is this something that can be seen on the loco or is this something internal and cannot be seen. I think that it is hard to see any differences between the SD90/43MAC (710 engine) and the new SD70MAC (they both use the 710 engine). Is the "phase ll" applied to the SD90/43MAC ? Can they fit the H engine into the SD70MAC ? That would be a 6000 hp SD70MAC if it would fit.

[YoHo1975]

I do not believe the MAC H is an official designation either whereas SD9043 is officially what UP called them. or 90/43 or some such. Though that the 265 powered units are off roster, they just say SD90MAC I believe.

[NorthWest]

SD70ACe vs SD90MAC*

There are lots of similarities in the locomotives, including the cabs (for the SD90MAC-H IIs). This is to be expected, as copying an earlier design is cheaper than creating a new one. All of the SD90MAC-H units are off of UP's active roster, so the numbers have been reused for SD70ACes.

Brazilian built SD70ACes have three radiator fans, having the same body as the SD80ACe, North American units have two.

*Naming convention that I use, I find SD9043 to be rather distasteful outside of railroad computer system use, as EMD has distinguished 265 from 710 units on its own.

SD90MAC: 4300HP 710

SD90MAC-H: 6000HP 265

SD90MAC-H II: Upgraded unofficial phase II of the SD90MAC-H

[doug u]

I looking at a website for SD70 (NEW Style) it seemed to have some SD43/90 mixed in. The two look very simular and they seem to go by the numbers on the loco. UP reuses the numbers which are all in the 8xxx series. I though the 70s have 2 cooling fans and 90 had 3 cooling fans. Did they ever reconfigure the fan for each type , the pictures seem to have 2 and 3 fans as SD70.