EMD 645

The EMD 645 is a line of diesel engines built by General Motors Electro-Motive Division. Each cylinder is of 645 in³ (10.57 l) displacement, hence the name; the bore is 9.1 in (231 mm) and the stroke is 10 in (254 mm), and the compression ratio is 14.5:1. The 645 succeeded EMD's earlier 567 series and was in turn replaced by the 710 series, but it is still sold and maintained by EMD for both locomotive, marine and stationary engine use.

The 645 series engine was introduced in 1965 in EMD's "40 series" (GP40, SD40) in 3,000 hp (2.2 MW) V16 form, and in V20, 3,600 hp (2.7 MW) form in the SD45. The last locomotives the 645 was installed in were the "50 series" (GP50 and SD50).

All 645 engines are V engines of 45° inclination between banks, and all are 2-stroke.

Versions

ID	Engine type	Induction	Max rpm	Power (hp)	Power (MW)	Introduced	Locomotive(s)
8-645E	V8	turbocharged	900	1500	1.1	1982	GP15T, MP15T
16-645E	V16	Roots blower	900	2000	1.5	1966	GP38, GP38-2, SD38, SD38-2
12-645E3	V12	turbocharged	900	2300	1.7	1968	GP39, GP39-2, SD39
16-645E3	V16	turbocharged	900	3000	2.2	1965	GP40, GP40-2, SD40, SD40A, SD40-2, SD40T-2, SDP40F
20-645E3	V20	turbocharged	900	3600	2.7	1965	SD45, SD45-2, F45, FP45
16-645E3A	V16	turbocharged	950	3300	2.5	1969	DDA40X
20-645E3A	V20	turbocharged	950	4200	3.1	1970	SD45X
16-645E3B	V16			3200			F40C
16-645F	V16	turbocharged		3500	2.6	1977	GP40X, GP50, SD40X, SD50

References

* Pacific Southwest Railway Museum. The History of EMD Diesel Engines. Retrieved on May 11, 2005.