Worlds largest engine

What is the worlds largest engine? The worlds biggest engine?

The phrases "world’s biggest engine" and "world’s biggest engine" is ambiguous because it lacks a clear reference frame or category; “biggest” and "largest" can mean several different things depending on context, purpose, and measurement criteria.

Sector Differences

Different industries define “engine” differently. A massive marine diesel engine powers container ships, a jet turbine like the GE9X drives aircraft, and rocket engines such as the Raptor or F‑1 produce unmatched thrust. Each could justifiably claim the title of “world’s biggest engine” within its sector, leading to natural ambiguity.

Comparative Language Issues

The term also suffers from linguistic ambiguity — "biggest" and "largest" are a relative adjective that implies comparison but not a fixed technical measure. Without specifying “biggest by what metric” or “in which category,” the statement becomes vague and open to misinterpretation.

In short, “world’s biggest engine” is ambiguous because “biggest” can signify entirely different metrics — mass, volume, or output — and “engine” itself applies to many unrelated machines across industries, each optimized for different functions.

Time issue

As time progresses, the target shifts. What was the biggest engine in 1920 is by any measure a medium size engine at todays standards. So we need to issue a timeframe to the equation too.

Physical Size (Mass and Dimensions)

If “biggest” refers to physical scale, then we measure total weight and external dimensions (height, length, width). This matters for stationary powerplants and ship engines, where installation space and total mass are significant.

Power Output (Horsepower or Kilowatts)

“Biggest” sometimes refers to power output — how much work the engine performs per unit time, measured in horsepower (hp) or kilowatts (kW). Proton rocket engines, jet turbines, and electrical generators are often ranked by this value.

Thrust (Newton or Pound‑force)

For jet and rocket engines, thrust is the key metric — the total forward force produced by propellant ejection. Rocket classifications like F‑1 or Raptor engines use kilonewtons (kN) or meganewtons (MN) to define “bigness”

Hybrid Metrics (Torque or Power‑to‑Weight)

Alternative measures such as torque (rotation force), or power‑to‑weight ratio (hp / kg) can provide more context, especially in performance or mobile applications like vehicles or aircraft.

Big engines, Large engines.

Engines, large ones, mostly mounted in ships, and there has been many famous names up thru the years.

What was a big engine in 1895 is shure a small engine today.

If we want the engine with the biggest bore, that honor probaly goes to the 1060 mm bore Fiat GMT

The Contenders - short, brief history.

It must be a crosshead engine, two stroke.

Burmeister & Wain

Doxford

Götaverken

Fiat GMT

MAN

Mitsubishi 12UEC85/180D

Stork-Werkspoor

Sulzer

Slow Speed 2 stroke crosshead engines from 2000 and onwards - The BIG ones
Engine type / serie	Variant	Cylinders	Bore mm	Stroke mm	Volume pr cyl liter	Volume engine liter	kW	bhp	Torque kNm	RPM	Length mm	Width mm	Height mm	Weight tonnes	Year in service
Sulzer RT-flex	14	14	960	2500	1809	25334	80080	108920	7498	102	27313	4480	13519	2300	2004
MAN B&W G95	C9	12	950	3460	2470	29640	82440	112126		80
MAN B&W K98	ME7 / MC-C7	14	980	2660	1617	22638	87220	119307		97	27885	4370	13450	2405
MAN B&W S90ME	C 9.2	14	900	3260	2040	28560	81340	110630		84

Ultra lareg bore engines

B&W K98FF, MAN KSZ105, Fiat 1060S. SULZER RND105

Older big engines - Major engine makers with "large" engines made

Engine maker	Trunk Cross head	Engine type	Single Double	Bore mm	Stroke mm	Volume pr cylinder	BHP pr cyl	MEP bar	RPM	Piston speed m/sec	Weight tonn	Year in service
Alfred Holt
AEG
AEG-Hesselman
Burmeister & Wain	CH	K98FF	SA	980	2000	1508.59	3800	10,8	103	6,86		1968
Deutsche Werft
Doxford
Fiat GMT	CH	1060S		1060	1900	1676.7	4000	10,0	106	6,71	1640	1971
Fullagar
Franco Tosi Meccanica
Götaverken
Harland & Wolff
Krupp
McIntosh and Seymour
MAN	CH	KSZ105/180		1050	1800	1558.62	4000	10,7	108	6,48		1969
Mitsubishi
North British Diesel Engine Company (NBDEC)
Nobel
Polar
Richardsons Westgarth
Sulzer	CH	RND 105		1050	1800	1558.62	4000	10,5	108	6,48		1969
Stork
Stork-Werkspoor
Still & Straight Diesel / Scott Engines
Swan Hunter
Vickers
Werkspoor
Worthington