Reliable and efficient four-stroke small-bore engines
Regulatory and fuel-related uncertainty can make it difficult to plan investments in propulsion and GenSets. With our small-bore engines, you are prepared for whatever lies ahead.
MAN Energy Solutions has built its position as the leading designer and developer of small-bore engines for the world’s merchant marine fleet on the basis of high reliability and efficiency.
Thanks to the low maintenance requirements, our engines provides extended lifetime, and additionally offer long time between overhauls (TBO). When needed, our service experts are there for you – every day and everywhere around the world.
MAN small-bore engine portfolio for the world’s merchant fleet
across the globe
Key benefits
Full range of MAN four-stroke small-bore engines
Explore the capabilities and range of our engines.
GenSets and Diesel-electric propulsion
MAN L28/32DF GenSet
Based on the ultra-reliable and robust MAN 28/32H, the dual-fuel version is available as newbuild or retrofit and adds the ability to run on methane, with its economic and environmental advantages. High efficiency in gas and diesel mode makes it a perfect GenSet as part of a complete power package with four-stroke or two-stroke propulsion engines. Easy operation, easy maintenance and proven reliability also make it a trusted propulsion engine with long times between overhauls and low life cycle costs.
- 720 – 750 rpm
- 1,050 – 1,890 kW
- 1,000 – 1,800 kWe
MAN L23/30H Mk3 GenSet
By applying innovative technology to classic design principles, the MAN L23/30H Mk3 is engineered to meet the power needs of most commercial ship types. Straight forward integration requirements make it a perfect choice for low-cost installation, while well-known maintenance procedures and common spare parts reduce operating costs. The new model raises power output per cylinder by 15-20% and reduces fuel oil consumption.
- 720 – 900 rpm
- 500 – 1,800 kW
- 475 – 1,710 kWe
MAN L23/30DF GenSet
The MAN L23/30DF dual-fuel GenSet lets you select the most economic fuel for the operating condition. The cost optimized fuel injection system is designed for high reliability and cost-efficiency. It uses the main injection valve to inject pilot oil. This way, separate injectors, piping and pumps for main oil and pilot oil or a common rail system are not needed, saving on installation costs and maintenance. The monocoque design also eases the installation of the engine series and reduces weight.
- 720 – 900 rpm
- 625 – 1,320 kW
- 590 – 1,255 kWe
This methanol-fuelled engine is a compact and reliable power source designed to run on methanol, heavy fuel oil (HFO), and most bio-fuel oils. When powered by green methanol, it is carbon neutral. The new engine type maintains the reliability and low consumption of the proven MAN 21/31, ensuring security of power supply on large vessels and handling load steps with confidence.
- 900 – 1,000 rpm
- 1,000 – 1,980 kW
- 950 – 1,880 kWe
Propulsion engines
The robust and reliable MAN L27/38 delivers good performance over the entire load range with quick acceleration and immediate load response. Its proven reliability ensures long time between overhauls (TBO) and no unscheduled maintenance or repair work.
This engine is available as methanol-ready version.
- 750 – 900 rpm
- 2,100 – 3,690 kW
MAN L21/31 propulsion
The MAN L21/31 engine combines intelligent use of fuel in marine applications with flexible propulsion systems. It is the ideal power source, for example, for small to medium-sized tankers, cargo ships and ferries.
The proven engine is characterized by its reliability and low consumption.
This engine is available as methanol-ready version.
- 1,000 rpm
- 1,290 – 1,935 kW
Plan your vessel with confidence
Get in touch with our four-stroke small-bore experts for in-depth advice on all your propulsion and GenSet questions. Start your change process now and reach out to us today.
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MAN L21/31DF-M and MAN L27/38DF-M
Discover our methanol-fuelled small-bore engines: MAN L21/31DF-M and MAN L27/38DF-M.
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Methanol GenSet
Engineers in Denmark are making shipboard power low-emission with the developing of a four-stroke methanol engine.
Related news
MAN PrimeServ to Offer Methanol Retrofits for Four-Stroke MAN engines from 2025
MAN PrimeServ – the after-sales brand of MAN Energy Solutions – has announced that, from 2025, it will offer a retrofit package for the conversion of conventional MAN four-stroke engines already in the field to dual-fuel methanol operation. Customers will initially be able to convert existing MAN 48/60 engines to the latest MAN 51/60R-DF-M engine type with methanol capability.
MAN Energy Solutions reports that the conversion package has been under development for some time and has been tested intensively at its Augsburg, Germany plant since summer 2024. MAN PrimeServ plans to convert the first four-stroke engines for a pilot customer in autumn 2025, at which stage the package will be made available to the general market.
Stefan Eefting, Head of MAN PrimeServ Germany, said: “Climate-neutral shipping can only be achieved with synthetic fuels and green methanol is particularly suitable for four-stroke applications due to its favourable energy-density. In this context, we have already received a large number of retrofit enquiries from customers who want to switch to methanol. With our new methanol-retrofit package, we can now offer customers an economically attractive opportunity to convert older engines to a future-proof type. In this way, we are protecting the climate together with our customers and ensure that their investments in our engines remain future-proof, with a very interesting ROI."
Alexander Knafl, Head of Engineering R&D Four-Stroke at MAN Energy Solutions, added: “We have already gained extensive experience in methanol operation with the MAN 51/60R-DF-M in a series of tests. We have achieved pleasing results in both combustion management and methanol injection and are now focusing on further optimisation. Our aim is to ensure a consistently high engine efficiency, regardless of the fuel type, diesel or methanol.”
Methanol retrofit is economically attractive
Accordingly, from 2025, customers will be able to have conventional MAN 48/60 engines converted to new MAN 51/60R-DF-M engines – both with or without a common-rail system. In addition to the converted engine's methanol capability, customers will also benefit from the engines’ significantly higher efficiency during diesel operation. The engines will also be equipped with the latest control and safety systems from MAN Energy Solutions.
Bernd Siebert, Head of Retrofits & Upgrades, MAN PrimeServ, added: “Converting existing engines to dual-fuel operation with synthetic fuels is of crucial importance to climate-neutral shipping. In addition to new engines, we also need concepts to decarbonise the existing fleet. After all, ships have a service life of 20 to 30 years and, from an economic point of view, retrofitting is also much more efficient than installing a new engine or building a new ship.”
Documents
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Contact
Jan Hoppe
Head of Group Communication & Marketing
Group Communications & MarketingMAN Energy Solutions SEStadtbachstr. 186153 AugsburgGermany
Jan.Hoppe@man-es.com t +49 821 322 3126Available languages
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- EN