A 3,400 hp (2.5 MW) ALCO 18-251 engine being used as a backup electrical generator at a wastewater plant in Montreal.

A V18 engine is an eighteen-cylinder piston engine where two banks of nine cylinders are arranged in a V configuration around a common crankshaft.

The V18 engine is a rare configuration and is primarily used in large diesel engines running at low operating speeds. These large V18 diesel engines have seen limited use in haul trucks, electricity generation, rail transport, and marine propulsion.

There are no known automobiles that have used V18 engines and no engine manufacturer has developed or produced a V18 engine for use in automobiles.

While the V18 is a more uncommon engine configuration, there are more common eighteen-cylinder engine configurations such as the W18, which has seen use in both automobiles and aircraft, and the Deltic, an opposed-piston eighteen-cylinder diesel engine created by D. Napier & Son which was used for a variety of applications.


Name Displacement Power output Fuel Notes
ALCO 18-251[1] 12,024 cu in (197.04 L) 4,500 hp (3.36 MW) Diesel Originally designed and manufactured by
American Locomotive Company; now manufactured by
Fairbanks Morse Engine.[1]
Caterpillar 3618 20,320 cu in (333 L) 9,655 hp (7.2 MW) Diesel Out of production
Cummins QSK78[2] 4,735 cu in (77.59 L) 3,500 hp (2.61 MW) Diesel Derived from the V16 QSK60.[2]
Marketed by Komatsu as the SSDA18V170.[3]
Fairbanks Morse Colt-Pielstick PC2.5 63,510 cu in (1,040 L) 11,700 hp (8.73 MW) Diesel In production
MAN V32/44CR 39,055 cu in (643 L) 14,483 hp (10.8 MW) Diesel In production
Wärtsilä 18V50DF[4] 125,000 cu in (2,050 L) 23,530 hp (17.55 MW) Diesel or
natural gas
Available for both marine propulsion and power generation, and used in e.g. Humboldt Bay power station.[5]

The BelAZ 75600 and Liebherr T 282B haul trucks are powered by the Cummins QSK78 engine, while the Komatsu 960E-1 haul truck is powered by the Komatsu SSDA18V170 engine.

In 1971, the Canadian locomotive manufacturer MLW-Worthington produced the MLW M640 prototype diesel-electric locomotive powered by a 4,000 hp (3.0 MW)ALCO 18-251 engine, however the locomotive did not reach production.

See also


  1. ^ a b "Power Solutions: 251 Diesel Engines" (PDF). Fairbanks Morse Engine. Retrieved 26 June 2011.
  2. ^ a b "Cummins QSK78". Cummins. Retrieved 25 June 2011.
  3. ^ "New Engine - Rated 3500 horsepower at any altitude". MINExpo Report. Retrieved 26 June 2011.
  4. ^ "Wärtsilä 50DF". Wärtsilä. Retrieved 2 August 2017.
  5. ^ Humboldt Bay, USA Power Plant Wartsila 18V50DF Natural Gas. Industrial Marine Power Forum. Retrieved 2011-10-22.