F unit engine replacement?

[rrbluesman]

I was pondering this possibility and I don't know if thew engine mechanics are possible to do so, but:

Let's assume I have an EMD F-3, F-7, or even an E-8. I want to return it to service mainline passenger trains, would it be possible to remove the old EMD diesel electric engines from them and replace them with a more modern EMD Diesel Electric (or similar) engines for better fuel management and mechanical efficiency? If so, how challenging would it be? If not, what can be done to either replace or improve the older engine? Thanks!

[DutchRailnut]

no just replacing diesel won't do a thing, for new diesel you need better cooling system.
better and higher rated electrical system, but most important a higher hp traction motor would not fit in those old trucks.

[chrisf]

Union Pacific has done this with their E-9s. I don't know all the details but I do know that they've removed the two V-12 EMD 567s and replaced them with one 2000 hp V-16 EMD 645. They're basically a GP38-2 internally.

[DutchRailnut]

but that would be downgrade, not upgrade

[Allen Hazen]

Victorian Railways (Australia) B-class diesels were, roughly speaking, an F7 type. (Six axles and a cab at each end, but roughly an F7.)
In the late 1980s (maybe early 1990s) a number were rebuilt with Turbocharged 12-cylinder 645 engines (2250 hp), redesignated A-class. As Dutch mentions, a new cooling system was required: the roof over the middle of cabody was built up to accommodate larger radiators.
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The rebuilt locomotives seem to be fairly successful, and have continued in service, but I think fewer than originally intended. Victorian Railways, at about the same time, bought a bunch of all-new locomotives that were functionally similar: six axle units with a 12-645T engine. These were hood units (with a cab at each end). I don't know if anyone ever admitted anything in public, but my impression is that top management at VR decided that allnew hoods were a better deal than rebuilt covered wagons.
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(Note that this is just a possibly relevant example: not an answer to your general question.)

[MEC407]

Rumor has it that Norfolk Southern's F9s have 16-645E engines under the hoods. I don't think I've ever seen this from NS or a reliable source, but I've heard it mentioned by several people... can anyone confirm?

[ELSDP45]

no just replacing diesel won't do a thing, for new diesel you need better cooling system.
better and higher rated electrical system, but most important a higher hp traction motor would not fit in those old trucks.

Upgrading traction motors should not be a problem, plenty of D77's in blombergs. Upgrading cooling shouldn't be to bad if you only go up to 2000 hp (same for electrical). The real question is whether it is worth the expense.

[litz]

We have a gp9r on the Blue Ridge Scenic...

It was rebuilt in the 90s, frame-up, kept the 567 block, but it has 645 power assemblies.

Wiring-wise, its basically a - 38...

At any rate the thing is a great engine. It can out climb a billy goat on hills.

[DutchRailnut]

Putting 645 power assemblies in a 567 does not raise HP as stroke is not full as in a 645 block.
It basically changes the 645 power assemblies into 567 power assemblies but with less leakage and better available parts.

[Allen Hazen]

DutchRailnut--
Could you elaborate on how 645 power assemblies work on a 567 block? Both the 567 and the 645 engine have 10" stroke (the bore was increased in going from 567 to 645 but not the stroke; the 710 engine increased the stroke to 11"), so -- unless something really funny has been done with a new crankshaft-- I would think a "645C" engine (645 power assemblies on the 567C block from a GP-9) would have the normal 10" stroke of a 645 engine.

It is true, I think, that 567 engines modified with 645 power assemblies are usually rated at a lower hp than a built-as-new 645 engine (with an E block)(*) would be: perhaps for safety since the block isn't as robust? But I had assumed the lower output was obtained by using less fuel.

(*) Example: in the 1970s, Amtrak had a number of E-9 (or maybe E-8) units rebuilt with 645 power assemblies. The rebuilt units were rated, i.i.r.c., at 2600 hp: higher than the 2400 of an as-built E-9, but lower than the 3000 you'd get from two 12-cylinder 645 engines as used in SW-1500 units. ... On the other hand, I think some unit with 645 power assemblies on a 567 block WERE rated as highly as a unit with the same number of cylinders in a factory-built (non-turbocharged) 645 engine. Example: Penn Central, I think, rebuilt its ex-New York Central GP-20 units with 645 cylinder assemblies, replacing the turbocharger with a Roots blower, and kept the 2000 hp rating (making the units in effect the equivalent of GP-38). And I think CMStP&P rated modified GP-9 at 2000 hp, even applying "GP-20" model-plates on them!

[DutchRailnut]

The 645 power assemblies have same bore but with 567 crankshaft do not get full stroke.
Using 645 power assemblies was necessity as 567 power assemblies are no longer produced.

[Allen Hazen]

DutchRailnut--
Thanks for reply! I'm still puzzled, though. The stroke (= distance up and down that the piston moves in the cylinder) is determined by the size of the crankshaft throws. Given that the 567 and 645 engine designs both call for 10" stroke, how could a 567 crankshaft NOT produce full stroke in a 645 power assembly?

[litz]

Internals like that are beyond me...

I can tell you that the gp9r we have in Blue Ridge is rated 1800 hp, just like a normal gp9.

[drvmusic]

Keep in mind that I know little about engineering, but the B&M F7 #4268 in North Conway is waiting on the prime mover from a GP-9 the 470 Club just acquired. Perhaps someone over on the Conway Scenic Railroad thread would have some input since someone is probably researching this topic.

[MEC407]

Putting a GP9 engine in an F7 is roughly equivalent to taking the engine out of a '59 Chevy and putting it in a '57 Chevy. In other words, it's not a huge stretch. In fact, they're basically interchangeable.

Granted, I'm not exactly sure what rrbluesman had in mind when he used the words "a more modern engine" in his original message... but I kind of assumed he meant something significantly more modern than what was originally under the hood. It's certainly true that a GP9 engine is more modern than an F7 engine, but it's also true that a '59 Chevy is more modern than a '57 Chevy. I think we'd all agree that neither vehicle is modern by today's standards, however. Likewise, if you've got an F7 with a GP9 engine under the hood, you've still got an antique locomotive with an antique engine.