GTW GP9R question

[emd_SD_60]

Did the rebuilt CV GP9's now under GTW ownership retain their 567's after their rebuild, or get 645's? Got one of these guys this afternoon:
http://www.rrpicturearchives.net/showPi ... ?id=306605 .

I would imagine they retained their 567's, like their "Paducahbuilt" GP11 look-alikes.

[2spot]

According to my sources, class GR417a GP9Rs were rebuilt between 1989-93 with 16-645C upgrades.

[Allen Hazen]

645C -- that means 645 power assemblies mounted on the original 567C crank case?
A lot of railroads did this. Sometimes, at least, it led to a 2000 hp rating.

[emd_SD_60]

So basically they retained their 567 blocks, and everything else (pistons, crankshaft and camshaft, heads to name a few) was 645?

[BlackDog]

I am going to guess that everything is origional on those GTW units except for the 645 power assemblies. The crankshaft, cam shaft, etc. stays the came. The 567 cylinder liner is pulled out, as is the piston (it is disconnected from the con rod) and the larger 645 pistons and assemblies are put in. I can't remember if the heads are the same, I believe they are. I think the rack needs to be readjusted.

I've seen SW-1's with 645 power packs in them. Diesel-Electric Service Corp. in St. Paul used to be great for doing things like that.

[DutchRailnut]

Correct every thing other than the cylinder/liner/head is 567.
The hp rating of engine goes up but it won't deliver the 2000 hp due to electrical system including the generator still having the lower hp rating.
The switch to 645 power assemblies is done only to make engines compatible with newer engines and to minimize part storage.
a added benefit is you got later technologie power assemblies with less leakage etc .

[2spot]

Dutch Railnut and BlackDog are correct. 645 power assemblies on a 567 block for simplification of parts inventories. They still rate these at 1750 HP. Sorry if I left that unclear.

[Allen Hazen]

2spot and Dutch Railnut--
Thanks for calling me on my (naive & uninformed) remark about 2000hp ratings! (One of the great things about posting to Railroad.Net is that if you don't know something when you post, you will afterwards!)

[[ONE bunch of 567-to-645 rebuilds wouldn't have any electrical problems with 2000 hp: the de-turboed GP20/GP30/GP35, starting (I think) with Penn Central's ex-NYC GP20. I suppose the engines on these would be described as "645D", since the turbocharged 567 (???other than "Omaha GP20"???) seem to have had 567D engines.]]

Curiosity question: CMStP&P (Milwaukee Road) had a bunch of rebuilt GP9 that WERE rated at 2000hp: they even had "GP20" nameplates made for them (imitating the style that EMD used for a few years around 1960). Did they have MAJOR electrical modifications in addition to the 645 power assemblies?

For that matter, what about the UP's "Omaha GP20" units? They were rebuilt from GP9, getting to 2000 hp by turbocharging their 567 engines rather than using 645 power assemblies (which would have involved going almost a decade forward in time machines to get them!). Did they have major electrical rebuilds, or did the original GP9 generator/motors/wiring/controls have enough overload capacity to handle the 14% boost in power?

[DutchRailnut]

The wiring probably has plenty to spare, but its the combination generator/alternator and traction motors that usually bites the dust unless it was too upgraded.

[byte]

I see those units go by my house fairly frequently. Evidently the exhaust system was something they didn't touch during the rebuilding, because they still sound very much like 567s.

[DutchRailnut]

They would still sound the same, same rootsblower, no Turbo.

[2spot]

Allen Hazen, believe me I'm not calling you on anything. I've learned more on these boards than I care to admit. This link is a data sheet for the ex-Milwaukee GP-20s now belonging to Georgetown RR from GRRs site (they are for sale): https://www.intra-focus.com/GTRR/DOCS/details.pdf Still show D-12 gens and D-77 TMs so the locomotives will handle the HP increase. The 16-645 was available with a lot more HP so there is probably a limit to what a GP-9 will accomodate without major mods. I dont recall any being converted to GP-40 specs (3000 HP).

[Allen Hazen]

Thanks, 2spot, for the Milwaukee "GP20" (rebuilt GP9) specs (which seem to come from a CMStP&P diagram book)!
There are a number of curious things about it, and I got more curious after comparing to specs for as-built GP9 from the Pennsylvania RR and New York Central RR diagram books (available on-line at George Elwood's marvelous "Fallen Flags" railphoto site,
http://www.rr-fallenflags.org ).

The Milwaukee units are listed as having 645E engines! I'm not going to get burned at the stake defending the truth of that -- clerical errors get made, even in official railroad documents -- but it suggests that they got new crankcases and NOT just new power assemblies on the old 567C base. So does the engine top speed of 900rpm (typical of 645E; the 567C in as-built GP9 did 835 rpm at top speed). So, maybe, do the figures for lube oil and cooling water: 217 gal and 227 gal respectively, as opposed to the 200 gal and 230 gal the PRR thought a GP9 took.

On the electrical side, the Milwaukee units have "D12-B-D-14" generators, whereas the NYC and PRR diagrams just show "D12-B": somebody who knows EMD generators better than I do (not hard!) might comment on whether the "D-14" on the Milwaukee diagram is just a minor subspecification the NYC and PRR diagram peope didn't bother including, or whether it marks a modification.

The Milwaukee units are shown as having D77 traction motors (the model used on EMD's 40-series units): the PRR diagram says D47 and the NYC diagram says D37. (Maybe the NYC diagram represents ealier-production GP9 than the Pennsy ones? Or maybe PRR had upgraded?) But I think many railroads gradually upgraded traction motors on their locomotives.

The D12 generator, unless it was modified and upgraded somehow, does seem like the "odd man out" in this combination!

[mxdata]

There is an EMD Modernization Recommendation that covers the changes needed to use 645 power assemblies in 567 engines. In addition to the use of the 645 power assembly it requires changing the camshaft counterweights because of the weight difference between the 567 and 645 pistons. This was described recently in the Railway Preservation News articles section (rypn.org) so there is no need for me to add any detail here.

[BR&P]

OK, time for me to learn something. If the pistons are heavier, wouldn't you want to change the counterweights on the CRANKshaft? The CAMshafts are gear driven, up in the top deck, and not directly affected by the pistons. Or is there another factor I'm not aware of? Thanks!