FAIRBANKS MORSE / ALCO 251F
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The FM/ALCO 251 F engine is universally recognized for its great reliability, high specific output, and low specific fuel consumption. This rugged 4-stroke engine is available in 6-, 8-, 12-, 16-, and 18-cylinder configurations and provides 500 to 2810 kWe of power. All versions feature exceptional commonality of components with 229 mm (9 in) bore and 267 mm (10.5 in) stroke used throughout, forged alloy crankshaft with nitrided bearings, welded counterweights, fabricated steel cylinder block with redesigned camshaft bearing supports, and an under slung crankshaft that is carried in forged steel saddles. The latest version of the FM/ALCO 251 F engine incorporates performance improvements known as the Plus Package. The "Plus" configuration has been engineered utilizing years of actual field experience with the intent to reduce fuel consumption and improve reliability and durability. The FM/ALCO 251 F "Plus" includes the following improvements: •  A stronger, more durable cylinder head casting increases the life of critical components such as valve seats and reduces thermal distortion and leaks. •  A new precision ground valve lever bushing that improves the reliability and service life of the valve train. •  A newly designed Super Bowl piston crown provides more thorough combustion and subsequent increased fuel efficiency. This provides a 11.5-to-1 compression ratio while using the same ring set and requires no change to the injection timing. •  A redesigned chrome pattern on the cylinder liner improves lubricity between the liner and piston and reduces lube oil consumption. •  Completely redesigned camshafts made of a stronger material to increase life. The new design also incorporates the "unit cam" concept, vastly improving maintainability by allowing replacement one cylinder at a time. •  Forged steel piston crowns are bolted to forged aluminum alloy piston bodies. •  Forged alloy crankshaft with nitrided bearings, welded counterweights. The under slung crankshaft is carried in forged steel saddles. Typical Dimensions CYLINDERS LENGTH (mm) HEIGHT (mm) WIDTH (mm) TONS 6L 6,743 3,486 2,692 26 8V 6,543 3,486 2,692 24 12V 8,573 3,486 2,692 28 16V 9,712 3,486 2,692 38 18V 10,465 3,486 2,692 43 Engine Data - Generator Power Cylinder Bore - mm (in) - 229 (9.0) Piston Stroke - mm (in) - 267 (10.5) Cycle - 4 Stroke Displacement / Cylinder - L (cu in) - 10.9 (668) Aspiration - Turbocharged - Aftercooled Rotation - CCW or CW Mean Piston Speed - m/s (ft/s) - 6.7 - 10.6 (21.8 - 35.0) BMEP - bar (psi) -- Continuous - 12.7 - 17.9 (185 - 260) -- Standby - 14.4 - 19.4 (210 - 282) MODEL 50HZ 750 RPM 50HZ 1000 RPM 60HZ 900 RPM 60HZ 1200 RPM DRY WEIGHT CYL BHP / kWe BHP / kWe BHP / kWe BHP / kWe LBS (kG) 6L 912/500 1215/870 1098/730 1400/1000 22500/10206 8V 1216/865 1624/1154 1464/1040 -- 25700/11658 12V 1825/1300 2430/1730 2200/1556 2800/2000 33000/14969 16V 2432/1730 3240/2307 2915/2076 3730/2650 42000/19050 18V 2736/2108 3654/2810 3924/2528 -- 49200/22317 All Ratings subject to factory approved application. Ratings are based on: 90 degree F (32.2 degree C) ambient temp. 28.25 in Hg. (71.6 cm Hg) barometric pressure (min) 1500 ft. (457 m) altitude (max) Standby ratings available The kWe ratings are based on generators with nominal efficiencies of 95.5%. For installations obtain certified prints. Engine Data - Marine Power MODEL 900 RPM 1000 RPM 1100 RPM 1200 RPM DRY WEIGHT CYL BHP / kWe BHP / kWe BHP / kWe BHP / kWe LBS (kG) 6L 1025/764 1215/906 1335/995 1400/1044 22500/10206 8V 1460/1089 1620/1208 -- -- 25700/11658 12V 2185/1629 2430/1812 2670/1991 2800/2088 33000/14969 16V 2915/2174 3240/2416 3560/2655 3725/2778 42000/19050 18V 3280/2446 3645/2718 4010/2990 -- 49200/22317 All Ratings subject to factory approved application. Ratings are based on: 90 degree F (32.2 degree C) ambient temp. 28.25 in Hg. (71.6 cm Hg) barometric pressure (min) Overload ratings available For installations obtain certified prints. Engine Data - Locomotive Power MODEL TYPE ENGINE SPEED ENGINE OUTPUT BMEP CYL 251- RPM gkW ghp bar psi 6L F 1100 1118 1500 18.6 269 8V F 1000 1357 1820 18.6 269 12V F 1100 2237 3000 18.6 269 16V F 1100 2983 4000 18.6 269 18V F 1100 3356 4500 18.6 269 All Ratings subject to factory approved application. Engine gross output complies with AAR and UIC classification. For installations obtain certified prints. Aftermarket Parts and Service for your FM/ALCO 251 F Only genuine Fairbanks Morse replacement parts and factory-direct field service can guarantee optimal performance for your FM/ALCO 251 F. With facilities located worldwide, Fairbanks Morse Engine provides around-the-clock FM/ALCO OEM replacement parts and factory-direct field service to customers in every market. Getting your genuine FMALCO OEM replacement parts in time and on time is crucial to the continued smooth operation of your Fairbanks Morse engine. Give us a call and we will quickly supply whatever you need. Can you afford to risk engine performance and downtime by using non-FM/ALCO OEM replacement parts? Not when everything you need is available from FME, delivering the highest quality at the right price. For more information, please visit our comprehensive parts and service pages.