Derated SD45 with odd mods?

@Ace posted:

Many years ago, in a magazine, I saw a photo and brief mention of a derated SD45 used as a heavy switcher somewhere back East. Same 20-cylinder engine but no turbocharger, reputedly. It had a cooling fan removed and blanked also. The horsepower capability was obviously reduced but it repurposed a tired old loco past its prime without a costly turbocharger replacement.

If true, I'm wondering if someone knows further details of this. Can an EMD 20-cylinder engine function with a 16-cylinder roots blower at lower RPM's? Or is there some other detail in modification? Was it a one-off?

Must admit that I never heard of such a thing. I do remember that M-K was taking 20 cylinder 645 engines and "cutting"  two banks of cylinders off one end of the crankcase (probably the front end), and making them into 16-645E3 engines.

It is actually a pretty complicated process for modify a turbocharged EMD engine to roots blown, as the entire rear gear train (Camshaft Drive Gear Train) and its housing must be changed-out, plus all the power assemblies (as the pistons have a different compression ratio for roots blown vs. turbocharged, and liners have different intake port sizes). Lastly, the roots blowers would NOT be able to supply sufficient combustion air to all the power assemblies.

It would have been much cheaper to purchase a "running take-out" EMD 16 cylinder roots blown engine and swap-out the 20-645E3 turbocharged engine, in my opinion.

Were the ones that Montana RailLink used were still rated at 3600 HP?

Seaboard Coast Line deturboed some SD35s and used them for hump pushers.  Have no idea what they did to them.

Not that I'm an expert, but never heard of that happening to a 20 cylinder.  16 cylinder in SD45 carbodies, yes - Watco has many of them.

@Chuck Sartor posted:

Were the ones that Montana RailLink used were still rated at 3600 HP?

Pretty sure they were, i.e. still 3600HP.

@NHVRYGray posted:

Seaboard Coast Line deturboed some SD35s and used them for hump pushers.  Have no idea what they did to them.

Removing the turbo from a 16-567D3A engine, and converting it to roots blown, would still require a lot of work (in the Waycross Back Shop), but would be MUCH more successful than trying the same modification to a 20-645E3 engine.

Not that I'm an expert, but never heard of that happening to a 20 cylinder.

Right.

16 cylinder in SD45 carbodies, yes - Watco has many of them.

Yes, there are/were lots of them.

I believe some of the NS SD45-2s have derated (3,000 hp) 20 cylinder prime movers

@EMD posted:

I believe some of the NS SD45-2s have derated (3,000 hp) 20 cylinder prime movers

But NOT by removing the turbocharger!!!!!

As I recall, this b@zd@rdized SD45 was shown in a photo with extended caption in Trains or CTC Board magazine maybe 25 - 35 years ago. The photo showed it parked in a fenced enclosure adjacent to interchange tracks. I'm thinking it was a cheap and dirty adaptation of old third-rate power for limited use.

Perhaps the exhaust was just diverted from the turbocharger, and the turbo still ran off the gear train to churn air for low-RPM power. As I recall, an EMD 645 turbo doesn't come off the gear train until notch 6 or 7.

Dunno why this old news came to mind recently! Thanks for the replies.

If a non-turbo, 6-axle 16-cylinder EMD is an SD38… is the non-turbo, 6-axle 20-cylinder an SD43?

CentralFan,

Excellent methodical rational!

@EMD posted:

I believe some of the NS SD45-2s have derated (3,000 hp) 20 cylinder prime movers

Yep.

NS 1703, 04, 05 still have the 20 cyl...the other engines you see the extra space in the car body

@CentralFan1976 posted:

If a non-turbo, 6-axle 16-cylinder EMD is an SD38… is the non-turbo, 6-axle 20-cylinder an SD43?

Nope. Since there has never been a non-turbocharged 20 cylinder EMD 645 nor 710 engine.

Here's a thought: if you put 567C cylinder assemblies in a 20-cylinder block it makes approximately similar displacement (+10℅) as a 16-cylinder 645 engine, so it could manage with a 16-645E roots blower arrangement for derated output. But as Hot Water says, it's major work to convert the drive train from turbo to blower. Still, it might have been a way to build an economy-version derated 20-cylinder engine with common secondhand parts albeit not EMD sanctioned.

Why bother? Because there used to be an abundance of retired SD45's and 567 engines which were not widely favored for factory-quality rebuild. Many years ago ...

When Union Pacific did their SW10 rebuild program circa 1980, they used 645 cylinder assemblies in old 12-cylinder 567C engine blocks. Yes, they fit.

I've heard rumors of 567C and 645 cylinder assemblies being used in the same engine but it doesn't sound like a good idea. Can't be done with older 567A and 567B cylinders and engine blocks which have different arrangements with integral water  passages.

I rediscovered the article I mentioned in my original post, in the April 1989 issue of CTC Board magazine. The loco was owned by Pontiki Coal in Kentucky. Photo caption says dynamic brakes removed, not turbocharger. But I did remember the part about a cooling fan also removed, which implies the unit is derated. There was some unresolved discussion of this unit on Trainorders.com four years ago. New puzzle is, what happened to the central air intake? See photo.

@Ace posted:

I rediscovered the article I mentioned in my original post, in the April 1989 issue of CTC Board magazine. The loco was owned by Pontiki Coal in Kentucky. Photo caption says dynamic brakes removed, not turbocharger. But I did remember the part about a cooling fan also removed, which implies the unit is derated. There was some unresolved discussion of this unit on Trainorders.com four years ago. New puzzle is, what happened to the central air intake? See photo.

Maybe they simply replaced the 20-645E3 with a 16-567C, or a 16-645E, roots blown prime mover, thus not requiring 3 cooling fans. Sure can't explain what they did to the central air compartment.

I found a reference with numerous photos which may be the same locomotive, reported to have a Cat or Cummins V-12 engine. The photos show the unit in derelict condition. Apparently it was an oddball low-budget conversion to make a heavy switcher for limited local use on a coal mining branch.

https://www.facebook.com/photo...pcb.3421719154545502