page_title: EMD 645
section_title: Specifications (many are common to 567 and 710 engines)
hierarchical_section_title: EMD 645 / Specifications (many are common to 567 and 710 engines)
caption_attribution_description: English: EMD 16-645, animated GIF to show cylinder firing order.
context_page_description: The EMD 645 is a family of diesel engines that was designed and manufactured by the Electro-Motive Division of General Motors. While the 645 series was intended primarily for locomotive, marine and stationary engine use, one 16-cylinder version powered the 33-19 "Titan" prototype haul truck designed by GM's Terex division.
  The 645 series was an evolution of the earlier 567 series and a precursor to the later 710 series. First introduced in 1965, the EMD 645 series remained in production on a by-request basis long after it was replaced by the 710, and most 645 service parts are still in production. The EMD 645 engine series is currently supported by Electro-Motive Diesel, Inc., which purchased the assets of the Electro-Motive Division from General Motors in 2005.
  In 1951, E. W. Kettering wrote a paper for the ASME entitled, History and Development of the 567 Series General Motors Locomotive Engine, which goes into great detail about the technical obstacles that were encountered during the development of the 567 engine.
context_section_description: All 645 engines are two-stroke 45-degree V-engines. Each cylinder is of 645 cubic inches (10.57 L) displacement, hence the name; with a bore of 9 ¹⁄₁₆ inches (230 mm), a stroke of 10 inches (254 mm) and a compression ratio of 14.5:1.  The engine is a uniflow design with four poppet-type exhaust valves in the cylinder head and charge air scavenging ports within the sides of the cylinders.  All engines use a single overhead camshaft per bank, with exhaust valves operated by two cam lobes (each of which operates two exhaust valves through a "bridge") and one cam lobe to operate the Unit injector which is in the center of the four exhaust valves.  Rocker arms are roller-equipped to eliminate friction while hydraulic valve actuators are used to eliminate valve lash. Post-1995 710 engines employ Electronic Unit injectors, however these injectors still utilize a camshaft-actuated piston pump, as on non-EFI injectors.
  Cylinders in each V-pair are directly opposite each other, and since all rods are always in compression, the connecting rods use a simple system of "fork" rods on one bank of cylinders and "blade" rods on the other (with the same stroke on both banks).  As all rods are alternately in compression or tension throughout all four engine cycles, competitor General Electric in its 7FDL engine series uses the more complex "articulated" connecting rods (with a slightly longer stroke on the bank with articulated rods). The engines are provided with either a single or twin Roots blower, or a single mechanically-assisted turbocharger, depending on required power output.
  For maintenance, a power assembly, consisting of a cylinder head, cylinder liner, piston, piston carrier and piston rod can be individually replaced relatively easily and quickly.  The engine block is made from flat, formed and rolled structural steel members and steel forgings welded into a single structure (a "weldment"), so it can easily be repaired using conventional shop tools.
  Orientation: The "front" of the engine (the engine governor and fluid pump end) is actually at the rear end of the locomotive, immediately adjacent to the locomotive's coolant supply and cooling system; the "rear" of the engine (the induction system and traction generator or alternator end) is at the front end of the locomotive, immediately adjacent to the locomotive's electrical cabinet.
  Rotation: Engine rotation is in the conventional clockwise direction, as viewed from the "front" of the engine, but is in a counterclockwise direction, as viewed from the front of the locomotive. Marine and stationary installations are available with either a left or a right-hand rotating engine.
  Firing order
  Eight cylinder: 1, 5, 3, 7, 4, 8, 2, 6
  Twelve cylinder: 1, 12, 7, 4, 3, 10, 9, 5, 2, 11, 8, 6
  Sixteen cylinder: 1, 8, 9, 16, 3, 6, 11, 14, 4, 5, 12, 13, 2, 7, 10, 15
  Twenty cylinder: 1, 19, 8, 11, 5, 18, 7, 15, 2, 17, 10, 12, 3, 20, 6, 13, 4, 16, 9, 14
  Exhaust valves: Four per cylinder
  Main bearings
  Eight cylinder: 5 (one-piece crankshaft)
  Twelve cylinder: 7 (one-piece crankshaft)
  Sixteen cylinder: 10 (two-piece crankshaft, pinned and bolted in the middle)
  Twenty cylinder: 12 (two-piece crankshaft, pinned and bolted in the middle)
  Fuel injection: Unit injector; Electronic unit injector in post-1995 engines
  Engine starting
  AC traction generator: Dual electric starting motors, parallel-connected 64 volt starters in early applications, series-connected 32 volt starters in late applications
  DC traction generator: Generator series field
  AC power generator: Dual pneumatic starters in most stationary engine applications
  Engine Control
  Woodward PGE locomotive governor, or equivalent, in non-EFI-equipped engines; EMD engine control unit in EFI-equipped engines
  Weight (E3B turbocharged models)
  Eight cylinder: 22,050 pounds (10.0 tonnes)
  Twelve cylinder: 28,306 pounds (12.8 tonnes)
  Sixteen cylinder: 36,425 pounds (16.5 tonnes)
  Twenty cylinder: 43,091 pounds (19.5 tonnes)
caption: 16-645 engine arrangement and firing order. 8-, 12-, and 20-645 have similar arrangements, with the right bank being numbered sequentially before the left bank, so a 20-645 would have cylinders #1–10 in the right bank and #11–20 in the left bank. The front of the engine is at the rear of the locomotive; the rear of the engine is at the front of the locomotive.