SD45 locomotives

[Anonymous]

Are these the peak of the 645 line (not counting those 2-engine DD locos) in terms of power and size?

And is it true that 20-645 was an 4-stroke engine?

If that is so, how do these things sound?

[SID6FIVE]

the 20-645 was a 2-stroke engine,and the highest rating that I'm aware of was 4200 hp in the SD45X...

[Anonymous]

That's strange, a guy I know who is an engineer in LA said these were the only 4-stroke EMD engines, I wonder where he got that idea.

Was there a 4-stroke variation on the 20-645 series or something like that?

[nanaimo73]

EMD's first 4-stroke engines are in the SD90MACS, otherwise known as the H engine.

[Anonymous]

ok, then this is settled, thanks

and what about the sound, how similar does it sound to 12-645E3 and 16-645E3?

[CSSHEGEWISCH]

The sound was generally similar to the smaller 645 engines and as a whole, 645 and 567 engines were not that different in sound. Both were 2-cycle engines and both had a 10" stroke.
The only other EMD model with a V-20 engine besides the members of the SD45 family was the SD80MAC, which had a V-20 710 engine.

[trainboyH16-44]

I think that the SD50 was the most poweful 645, or was it just short? Can someone remind me?
Matthew

[Anonymous]

QUOTE: Originally posted by CSSHEGEWISCH

The sound was generally similar to the smaller 645 engines and as a whole, 645 and 567 engines were not that different in sound. Both were 2-cycle engines and both had a 10" stroke.
The only other EMD model with a V-20 engine besides the members of the SD45 family was the SD80MAC, which had a V-20 710 engine.

Well, while 567 and 645 do have some things in common regarding sound, I can always tell which is which, specially in idle, there is an obvious difference for anyone that is into locomotives i think (I mean, a grandma passing by won't tell the difference of course)

[Anonymous]

[
Well, while 567 and 645 do have some things in common regarding sound, I can always tell which is which, specially in idle, there is an obvious difference for anyone that is into locomotives i think (I mean, a grandma passing by won't tell the difference of course)


[/quote
Is telling the difference at idle part of the test for being a railfan? I better study, then.[;)]

[Anonymous]

no, I didn't mean that such things is what it takes to be a railfan, I ment that usually all railfans know these things because they pay attention to such details.

[dwil89]

QUOTE: Originally posted by trainboyH16-44

I think that the SD50 was the most poweful 645, or was it just short? Can someone remind me?
Matthew

The SD50 made somewhere around 3500-3600 HP with a 16 cylinder 645...it was probably the most powerful of the 16 cylinder 645's...making about the same HP as the 3600 HP in the 20 cylinder 645 in the SD45 and SD45-2.

[Anonymous]

BY the way, how do you "rate" a prime mover to higher HP? Isn't its HP determined by fixed things like size of cylinders, number of cylinders, max RPM etc etc?
What do they change in it to get say 4200hp from standard 3600?

[adrianspeeder]

Fuel delivery for one.

Ahhh, the good ole EMD "Hustle Muscle".

Adrianspeeder

[Anonymous]

QUOTE: Originally posted by electro-ortcele

Are these the peak of the 645 line (not counting those 2-engine DD locos) in terms of power and size?

And is it true that 20-645 was an 4-stroke engine?

If that is so, how do these things sound?

I was out in Montana Railfanning the Montana Rail Link where they use sets of four or five 20 cylendar 645 SD45s as helpers, and I heard those beasts at run 8 doing like 5 mph. THEY SCREAM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[eolafan]

Like Chris said above, the SD45's are really screamers. I occassionally get to the old WC yard in Stevens Point, WI and see some 45's there idling and really love the high pitched "scream" they make, even while idleing. At speed, the sound they make is really something to hear!

[rvos1979]

QUOTE: Originally posted by electro-ortcele

BY the way, how do you "rate" a prime mover to higher HP? Isn't its HP determined by fixed things like size of cylinders, number of cylinders, max RPM etc etc?
What do they change in it to get say 4200hp from standard 3600?

One can get various horsepower ratings from the same engine by adjustment of fuel settings. On EMD and the old Detroit 2-stroke engines, it is accomplished by adjusting the fuel rack and using different injectors. On other engines it is accomplished by either bigger injectors, bigger injection pump, changing out torque plates in the pump, and different air intake setups (turbo(s), aftercooler or intercooler).

One only has to look at the sport of diesel tractor pulling to see what kind of horsepower can be extracted out of a diesel engine.

Randy

[rvos1979]

QUOTE: Originally posted by electro-ortcele

ok, then this is settled, thanks

and what about the sound, how similar does it sound to 12-645E3 and 16-645E3?

I used to live about three miles from the Wisconsin Central tracks in Burlington, WI, and could always hear the 45s throttling up after leaving town. The big V-20s have a throbbing sound to them under load that I just was never able to hear from the V-12s or V-16s.

Up close, the turbo whistle is more pronounced, and gets to be higher pitched in the upper throttle notches. To someone who has grown up around diesels, it's just music to my ears.

Randy

[broncoman]

Since we are on the subject, does anyone know if they ever de-turboed a 20-645 for railroad use (like what UP is doing to many of its old SD40-2s for yard service)?
I know that UP derated the SD50s, did any of the other roads that ended up with them do the same?

Dave

[Anonymous]

Good question, but I don;t know, sorry[B)]

[Anonymous]

QUOTE: [
One only has to look at the sport of diesel tractor pulling to see what kind of horsepower can be extracted out of a diesel engine.

Randy

just gotta play with the 'ol "farmer screw" on the injection pump and you can often triple the power on a tractor. with all that power however, you can only run it for a short time as you'll burn the motor up.

[Anonymous]

I'd guess you can do much the same things as you would with a smaller diesel power unit. If it has a turbo the usual technique is to fit a larger intercooler (cooler air = higher density = more oxygen) and a large free-flowing exhaust system. You can also turn the turbo boost pressure up though this is risky as it can reduce engine and/or component life - it's only worth trying in combination with other modifications usually. Other options include switching to metal cylinder head gaskets, though I'm unsure if that would work on a big diesel. After that it's a case of optimising the fuelling to get the best power from the engine, and possibly spending more time on maintainance - merely changing the oil can give you something of a boost as old oil tends to thicken.

[beaulieu]

QUOTE: Originally posted by broncoman

Since we are on the subject, does anyone know if they ever de-turboed a 20-645 for railroad use (like what UP is doing to many of its old SD40-2s for yard service)?
I know that UP derated the SD50s, did any of the other roads that ended up with them do the same?

Dave

No, nobody has de-turboed a SD45 because nobody is building Roots Blowers of a capcity to operate the engine. The Roots Blowers of a 38 series locomotive replace the turbo of a 40 series locomotive, but if you put those blowers on a V20 you would have incomplete scavanging of the exhaust and recharge of air in the cylinders. This wastes fuel and creates more pollution. a 2-stroke diesel will not work properly without the correct capacity blower or turbo. While there have been a lot of SD40-2s built, there haven't been a lot of SD38-2s built because it is a niche. The reason some SD40-2s are being de-turbo to fill that niche is because no builder is building a current model to replace the SD38-2. The niche is getting smaller but it hasn't gone away. It is no longer big enough to interest the locomotive builders, but the railroads still need to fill it, so they improvise.

[arbfbe]

Many railroads derated their SD45's from 3600 hp to 3300 hp to improve the life span and reliability of the prime movers. This was done by reducing the flow of fuel through the injectors for the most part. The upgraded block that came with the SD45-2 did not have the bearing problems the earlier 20 cyl block had so there was no need to derate those engines. All of MRL's fleet of SD45's have the improved engine bearings and are set to produce the full 3600 hp.

[trainboyH16-44]

I think M-K has modified some SD45s to SD40M-2s, with I think SD40 engines.
Matthew