EMD Miscellaneous Notes
This page was last updated on February 26, 2015.
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.
Addiitional 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 sold 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)