EMD Miscellaneous Notes

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This page was last updated on March 30, 2021.

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Heavy Block 645

The following comes from Alex Huff, in an email dated January 1, 2006:

 I am not an expert here, but it is my understanding that early 645 engines suffered from cracks in the crankcase (E design). Later engines had reinforced crankcases, the E3B, known as "heavy blocks".

On the subject of crankcases, EMD Replacement Parts Catalog No. 301, Parts List No. A300 lists locomotives with 567 engines installed with C, CR and E crankcases. Footnotes state that replacement 567 engines will have a 645 crankcase and oil pan with 567 components. No 645 replacement was available for 6-567C and 12-567A crankcases.

Locomotives listed as built new with E crankcases are GA8, GL8, G8, GA18, G12, GR12, G22, G16, and SDP28. It should be noted that most were also shown with 567C engines.

Additional information about the Heavy Block version of EMD's 645 engine:

The so-called GE version of the EMD 645F being made in Poland is simply the former MK Rail/MPI version of the EMD "heavy block" 645. The heavy block 645 is the favored version for all 645 engines, and MPI had identified the source in Poland before they were sold to GE. All the rebuilders use the heavy block 645 because it is a much better version of the standard 645 design, due to better, more solid construction and better water flow. It sits on an improved, more reliable version of the F crankcase. The heavy block 645 has been a feature of all of UP's Life Extension SD40-2s, including the ex SP and ex D&RGW SD40T-2s that went through the program. These heavy block 645s were all purchased from MK Rail/MPI. The retired UP SD40-2s with heavy block 645s (not always Life Extension units) are the first to be sold at the surplus auctions. (Don Strack, email to Diesel Modeler's List, January 11, 2003)

More information about the 645F engine built in Poland, from the Railroad.net discussion forum in 2004:

When Morrison Knudsen announced their intention to build new high horsepower MK5000C locomotives competing with EMD and GE back in the early 1990s, EMD ceased sales of parts to the MK companies. MK responded with a program which sought replacements for most of the significant parts of the EMD engines and locomotives. One such item was the 16-645F3 engine crankcase, and a replacement was designed which differed in several respects from the EMD crankcase but accepted all the same reciprocating and rotating parts. The task of acquisition of engine crankcases was assigned to MK Engine Systems of Latham, New York, working with a contractor in Poland. MK subsequently spun off the rail operations as MK Rail, which later became Motivepower Industries. Motivepower then was merged with Westinghouse Air Brake to form Wabtec, and Wabtec subsequently decided to sell several operations, including Engine Systems, to General Electric. Thus GE ended up with the Polish built substitute 16-645F3 crankcase, and is still producing them.

The 645F equivalent crankcase marketed by GE Engine Systems in Latham, New York is commonly called a "645FZ" to differentiate it from EMD manufactured products. The "Z" stands for "Zagoda", which is the Polish firm that actually does the assembly and machining of the crankcases. While the crankcase looks like, and takes the place of, an EMD 645F crankcase, the design of the internal structure is significantly different.

Effectively, Metra MP36PH-3S and Caltrain MP36PH-3C 16-645F3B are "Polish blocks" and develop 3600hp@954 RPM. Both are EPA Tier-1 compliant. Metra uses QTRON's QES-III, Caltrain is equiped with the standard Woodward PG pressure-compensated engine governor.

SD40-2 Rear Circles

Don Strack wrote the following to the "DList" public discussion group on October 9, 1998:

Everyone knows what the upper openings on the rear hood end on EMD's -2 line locomotives are, right? Alternate locations for the classification lights. Wrong!

They are actually openings to allow access to the breather line on the upper corner of the radiator. From my years at UP, one of the jobs we did regularly on SD40s (built in 1966) was to cut some of the interior body sheet metal at the upper, outside corner at the rear of the car body to allow pipefitters access to this breather line. When EMD added the upper opening on the outside on the Dash 2 line, it was a great work saver. The plates came right out after removing the rubber gasket strip, and hung from a light-duty chain welded to the inside of the hood end. The access openings are the same size as the class lights merely for ease of manufacture, since the openings are stamped.

After I left UP in 1979, I made a conscious effort to ignore railroading for a couple years, then I turned to modeling narrow gauge. I returned to HO diesel modeling in 1983 when Athearn released their great SD40-2. I lost touch with diesel details and such, so I can't say what was done on the 50 line or 60 line. I don't collect or take very many photos, so maybe someone can enlighten me about the current rear hood design features. I vaguely remember the ends being completely blank.

(The DList was an online discussion group for model railroaders with an interest in diesel locomotives.)

(Don Strack was a mechanic in Union Pacific's Salt Lake City shops from 1969 to 1979.)

Don Strack wrote the following to the Observation Car public discussion group on YahooGroups on December 12, 2003:

On the subject of "alternate classification light openings" on the Dash 2 series beginning in 1972. This one was pure speculation on the part of Don Dover as he wrote the captions for the first photos of new SD45 tunnel motors in January 1972; and it stuck like super glue.

The opening provided access to the radiator breather pipes, using the easy-to-remove rubber gaskets that were also used on the class light openings. Having an access opening helped the pipefitters greatly, so that they did not have to have 6-foot long arms to get up into the very tight spaces of the upper rear corner of the carbody.

I told Dover about this almost right after he did his speculative captions 30 years ago, sending him this exact photo a year or so later. But he never wrote on the subject again. It's a pity too, since the myth still pops up occasionally.

Here is a photo Don Strack took in January 1974, showing the covers removed and hanging from chains, to allow access to the radiator vent lines.


Here is a photo of an Illinois Central SD70, showing that the openings were not an alternate location for classification lights, since SD70s were first built in 1993, after classification lights were no longer required.


For locomotives built by General Motors' Electro-Motive Division, the classification light assembly used by EMD (part number 8411537) was first used on the company's GP30s in 1962, and its use continued through to the end of Dash 2 production in 1980. Extensive research using a wide variety of photographs has not yet found any evidence showing the upper "knockout" openings being used for any purpose, including classification lights.

Jack Wheelihan wrote the following on Trainorders.com on September 17, 2017:

Sometime in the early to mid 1970s, EMD stopped equipping ALL units with "class lights" as well as "flag and lamp holding brackets", as a "basic" item. Those railroads that still desired "class lights" and "flag and lamp holding brackets" then had to pay extra for such features, and most railroads no longer desired, nor used such features, ever since train classifications, such as "Extra" (white class lights), and "Second Section Following" (green class lights), were no longer used.

(Read more about when the railroads stopped using classification and marker lights, with a focus on Union Pacific)