Engine Frame

Crankshaft

Connecting Rod

Piston

Cylinder Liner

Piston Rod

Exhaust Valve and Seat

Fuel Pump

MAN Marine Engines: Model Range

Model	Model	Model	Model	Model
KZ 52/90N	KZ 60/105E	KZ 70/120E	KZ 78/155	KZ 78/155E
KZ 78/155F	KZ 86/160	KZ 86/160F	KZ 90/160	KSZ 52/105C
KSZ 52/105CL	KSZ 70/120E	KSZ 70/125	KSZ 70/125A	KSZ 70/125B
KSZ 70/125BL	KSZ 78/155A	KSZ 86/160A	KSZ 90/160A	KSZ 90/160B
KSZ 90/160BL	KSZ 90/190	KSZ 105/180	58/64BL	GV 16/18ATL
20/27	GV 23.5/33ATL	GV 30/45ATL	40/45	40/54
40/54A	40/60	48/60	52/55	52/55A
52/55B	58/64

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MAN Engines offers a comprehensive portfolio of robust and efficient marine propulsion systems, ranging from compact inboards to powerful commercial workboat engines. The alphanumeric codes denote specific model families and their technical characteristics.

Below is a breakdown of the model series you provided.

1. KZ Series: Compact Inline Engines

The KZ series represents MAN’s classic, mechanically controlled inline marine diesel engines, renowned for their simplicity, durability, and torque. They are a popular choice for traditional workboats, fishing vessels, and heavy-duty applications.

KZ 52/90N: A durable, naturally aspirated engine.
KZ 60/105E | KZ 70/120E: “E” often denotes early turbocharged versions for increased power and efficiency.
KZ 78/155 | KZ 78/155E | KZ 78/155F: A powerful model where “E” may indicate turbocharging and “F” likely represents a further refined version with intercooling (charge air cooling) for maximum performance.
KZ 86/160 | KZ 86/160F: The “F” variant indicates an intercooled engine, delivering higher power output from the same displacement.
KZ 90/160: A larger displacement model for high-torque applications.

2. KSZ Series: Advanced Inline Engines

The KSZ series is the evolution of the KZ line. These engines often feature more modern technologies, including advanced turbocharging, improved cooling systems, and often electronic management for optimized performance and lower emissions.

KSZ 52/105C | KSZ 52/105CL: “C” suggests a modernized version; “CL” may indicate a special configuration (e.g., counterclockwise rotation).
KSZ 70/120E | KSZ 70/125 | KSZ 70/125A | KSZ 70/125B | KSZ 70/125BL: This family shows progressive development (A, B revisions). “BL” often signifies a counter-rotating (“left-hand”) engine for twin-installations.
KSZ 78/155A: An advanced version of the reliable 78/155 block.
KSZ 86/160A | KSZ 90/160A | KSZ 90/160B | KSZ 90/160BL: Modern, high-performance engines where “A/B” are design revisions and “BL” indicates a counter-rotating model.
KSZ 90/190 | KSZ 105/180: Larger displacement engines designed for significant power and torque, suitable for larger commercial vessels.

3. D Series (58/64BL): Modern V-Engine Platform

This refers to a specific model from MAN’s highly successful D2840 or D2842 series of V-type engines. These are modern, high-speed diesel engines known for their exceptional power-to-weight ratio and are widely used in high-performance yachts, fast ferries, and patrol boats.

58/64BL: The numbers refer to the bore and stroke (58mm x 64mm). “BL” likely denotes a counter-rotating model for twin-propeller setups.

4. GV Series: High-Speed V8 & V10 Engines

The GV series comprises high-performance, lightweight V8 and V10 engines derived from automotive racing technology. They are designed for high-speed planing yachts and applications where maximum power and minimal weight are critical.

GV 16/18ATL | GV 23.5/33ATL | GV 30/45ATL: These codes are unique to this series. The first number often relates to displacement in liters (e.g., ~16L), while the second number refers to power output in hundred(s) of kW or HP. “ATL” likely signifies a specific marine transmission or gearbox system.

5. Classic Inline Engines (40/45, 48/60, etc.)

This category includes some of MAN’s most iconic and globally recognized marine diesel engines. Known for their legendary longevity and mechanical simplicity, these models have powered countless fishing boats, tugboats, and commercial vessels for decades.

40/45 | 40/54 | 40/54A | 40/60: The prolific “40” series. The numbers typically refer to bore (in cm) and stroke (in cm), or a power rating. Revisions (A) indicate improvements.
48/60: A larger, powerful inline engine for medium-sized vessels.
52/55 | 52/55A | 52/55B: A highly successful engine family where “A” and “B” mark significant technical upgrades over the base model.
58/64: This is the bore/stroke designation for the larger inline engines that preceded the modern V-type D28 series.

Understanding MAN’s Model Numbering System:

Letters (Prefix): Indicate the engine family (e.g., KZ, KSZ, GV, D).
First Numbers (e.g., 52/90): Traditionally, the first number indicated the bore in centimeters, and the second number indicated the stroke in millimeters or a power rating. In modern engines (like the D series), it’s literally the bore and stroke in mm (58/64).
Suffix Letters (e.g., E, F, A, B, L): Denote technical features or revisions:
- E: Turbocharged
- F: Turbocharged and Intercooled
- A, B, C: Successive design revisions and improvements.
- L / BL: “Left” or “Counter-Rotating” engine (for twin screws).

B&W Marine Diesel Engines: Model Range

Model	Model	Model	Model	Model
50/110	42VT2BF	62VT2BF	74VT2BF	84VT2BF
42EF	62EF	74EF	84EF	K45GF
K67GF	K80GF	K90GF	L45GF	L67GF
L80GF	L90GF	L45GFC	L67GFC	L80GFC
L90GFC	L45GFCA	L67GFCA	L80GFCA	L90GFCA
L45GB	L67GB	L80GB	L90GB	L35MC
L35MCE	L42MC	L50MC	L50MCE	L60MC
L60MCE	L70MC	L70MCE	L80MC	L80MCE
K90MC	K90MCE	L90MC	S 35MC	S 42MC
S 50MC	S 60MC	S 70MC	S 80MC	S 90MC
S 60MC-C	S 70MC-C	S 80MC-C	S 90MC-C

B&W (Burmeister & Wain) is a historic and foundational brand in marine propulsion, renowned for its two-stroke low-speed crosshead engines. The models listed represent the evolution from older, smaller bore engines to the modern, highly efficient MC and ME series that dominate the world’s merchant fleet. The B&W brand is now part of MAN Energy Solutions.

Below is a breakdown of the model series you provided.

1. VT2BF Series: Early Two-Stroke Engines

These models represent an earlier generation of B&W’s two-stroke engine design.

Naming: The number (e.g., 42, 62, 74, 84) refers to the cylinder bore in centimeters.
Technology: “VT” indicates a design with scavenge air ports and exhaust valves. “2” likely refers to the engine series. “BF” signifies a turbocharged (Blown) engine with a Flywheel.
Examples: 42VT2BF, 62VT2BF, 74VT2BF, 84VT2BF

2. EF Series: The “E” Type Engine

A very successful and long-lived series of two-stroke engines, known for their reliability and mechanical simplicity.

Naming: The number is the bore in cm. “EF” stands for Exhaust valve & Flywheel (turbocharged).
Examples: 42EF, 62EF, 74EF, 84EF

3. K-GF & L-GF Series: The “Green Ultra Long Stroke” Revolution

This was a monumental shift in engine design. The “K” and “L” series introduced the “long-stroke” concept, which significantly reduced engine speed (RPM) to allow for the use of large, highly efficient propellers. This drastically improved fuel economy and made them the industry standard for decades.

Naming: The letter (K or L) denotes the stroke-to-bore ratio (L being longer stroke than K). The number is the bore in cm. “GF” stands for Geared Flywheel (turbocharged).
Examples: K45GF, K67GF, K80GF, K90GF, L45GF, L67GF, L80GF, L90GF

4. L-GFC Series: “Constant Pressure” Turbocharging

An evolution of the GF series, introducing more efficient turbocharging technology.

Naming: “GFC” stands for Geared, Flywheel, Constant pressure turbocharging. This system uses a single large exhaust manifold to provide a constant pressure to the turbocharger, improving efficiency at lower loads.
Examples: L45GFC, L67GFC, L80GFC, L90GFC

5. L-GFCA Series: “Advanced” Constant Pressure

A further refinement of the GFC design with incremental improvements.

Naming: The “A” suffix stands for Advanced.
Examples: L45GFCA, L67GFCA, L80GFCA, L90GFCA

6. L-GB Series: “B” Type Engines

Naming: The “GB” suffix is less common but follows the pattern, where “B” may indicate a specific design variant or a By-pass turbocharging system.
Examples: L45GB, L67GB, L80GB, L90GB

7. L-MC / K-MC Series: The “MC” – Mechanical Control

The introduction of the MC (Manually Controlled) series marked the beginning of the modern era. While still mechanically controlled, they featured numerous design improvements over the GF series for higher efficiency and reliability. They are the direct predecessors to the electronic ME engines.

Naming: “MC” is the key identifier. “L” or “K” indicates the stroke length. “E” suffix (e.g., MCE) indicates an Economical version, often with a higher maximum pressure and improved efficiency.
Examples: L35MC, L35MCE, L50MC, L50MCE, L60MC, L60MCE, L70MC, L70MCE, L80MC, L80MCE, K90MC, K90MCE

8. S-MC Series: The “Super” Long Stroke

The “S” designation took the long-stroke concept even further, creating Super-long-stroke engines. These run at even slower speeds (sometimes as low as 60-80 RPM), perfectly matching the propeller curve for maximum fuel efficiency. They are the most common engines on large container ships, bulk carriers, and tankers.

Naming: “S-MC” is the key identifier.
Examples: S35MC, S42MC, S50MC, S60MC, S70MC, S80MC, S90MC

9. S-MC-C Series: The “Compact” Design

A major innovation where the engine structure was redesigned to be more compact and lighter without sacrificing power. The “C” stands for Compact.

Naming: “S-MC-C” identifies this advanced, weight-optimized design.
Examples: S60MC-C, S70MC-C, S80MC-C, S90MC-C

Understanding B&W’s Model Numbering System:

Prefix Letter (L, K, S): Indicates the stroke-to-bore ratio and generation (S being the longest and most modern).
Number (35, 42, 50, etc.): The cylinder bore in centimeters. An S90MC has a 90 cm bore.
Main Suffix (MC, GF, EF): Indicates the engine family and level of technology.
- EF -> GF -> GFC -> MC -> MC-C shows the chronological evolution.
Secondary Suffix (E, A, C): Denotes specific versions or improvements within a family (E = Economy, A = Advanced, C = Compact).

Sulzer Marine Diesel Engines: Model Range

Model	Model	Model	Model	Model
TAD 36	TAD 48	TAD 56	RD 56	RD 68
RD 90	RND 68	RND 76	RND 90	RND 68M
RND 76M	RND 90M	RLA 56	RLA 66	RLA 76
RLA 90	RLB 66	RLB 76	RLB 90	RTA 38
RTA 48	RTA 52	RTA 58	RTA 62	RTA 68
RTA 72	RTA 84	RTA 96	RTA 52U	RTA 62U
RTA 72U	RTA 84C	RTA 84T	RTA 84M	RD 76
AL 20	AL 20D	AL 20H	AL 20/24	BAH 22
AL 25/30	AL 25D	AL 25H	ASL 25	ASL 25/30
ASL 25/30H	ATL 25	ATL 25/30	ATL 25/30H	S 20
S 20H	Z 40L	ZL 40	ZL 40/48	ZAL 40S

Sulzer is a name synonymous with innovation in marine propulsion, particularly for its large two-stroke engines that have powered a significant portion of the world’s merchant fleet. The models listed trace the evolution from small auxiliary units to the most advanced low-speed crosshead engines. The Sulzer brand is now part of WinGD (Winterthur Gas & Diesel Ltd.), a subsidiary of CSSC.

Below is a breakdown of the model series you provided.

1. Four-Stroke Auxiliary and Propulsion Engines

These are smaller, high-speed engines used for auxiliary power (generators) or for propelling smaller vessels like tugs, ferries, and yachts.

TAD Series: Modern, turbocharged and charge-air cooled (Turbo, Air-cooled, Diesel) engines. Numbers indicate displacement per cylinder (e.g., TAD 36 = ~36L/cyl).
- TAD 36, TAD 48, TAD 56
AL / ASL / ATL Series: A long-standing and highly successful series of four-stroke engines. The letters indicate the configuration and aspiration:
- A = General series prefix.
- L = Low-speed version for auxiliary generators.
- S = Supercharged (turbocharged).
- T = Turbocharged.
- H = High-output version.
- D = Direct Reversible for propulsion.
- Numbers (e.g., 20/24) refer to bore and stroke in decimeters.
- Examples: AL 20, AL 20D, AL 20H, AL 20/24, AL 25/30, ASL 25, ATL 25, ATL 25/30H
S & Z Series: Older generations of four-stroke engines.
- S 20: Supercharged engine.
- Z 40L, ZL 40/48: Z type engine, likely with a specific cylinder arrangement. L for low-speed.
- ZAL 40S: A specialized variant.

2. Two-Stroke Low-Speed Crosshead Engines (The Sulzer Legacy)

This is the core of Sulzer’s reputation. These massive engines are directly coupled to the propeller and are designed for maximum efficiency and reliability on large ocean-going vessels. The naming convention reveals their technological generation.

A. RD & RND Series: The Classic Engines
These were the workhorses of the mid-20th century, known for their robust mechanical design.

RD Series: Relative Displacement design (uniflow scavenging with a central exhaust valve). The number indicates the cylinder bore in centimeters (e.g., RD 56 = 56 cm bore).
- RD 56, RD 68, RD 76, RD 90
RND Series: An evolution of the RD, with New Design features for improved efficiency and lower fuel consumption.
- RND 68, RND 76, RND 90
RND-M Series: The Modified version of the RND, featuring further refinements for even better economy.
- RND 68M, RND 76M, RND 90M

B. RLA & RLB Series: The Long-Stroke Revolution
This series introduced the “long-stroke” concept. By increasing the piston stroke, the engine could run much slower, allowing for the use of a larger, slower-turning, and more efficient propeller. This was a landmark achievement in reducing fuel consumption.

RLA Series: Relative Long-stroke, A type. The number is the bore in cm.
- RLA 56, RLA 66, RLA 76, RLA 90
RLB Series: An improved version of the RLA, the Relative Long-stroke, B type, with further efficiency gains.
- RLB 66, RLB 76, RLB 90

C. RTA Series: The Modern Era
The RTA (Relative Tandem Articulated) series represents the final and most advanced stage of Sulzer’s mechanical engine development. It introduced a single, hydraulically actuated exhaust valve per cylinder and a chain drive for the camshaft, leading to greater reliability and efficiency. This series directly competes with MAN B&W’s MC engines.

Standard RTA: The number indicates the bore in cm.
- RTA 38, RTA 48, RTA 52, RTA 58, RTA 62, RTA 68, RTA 72, RTA 84, RTA 96
RTA-U Series: The “U”ltra-long stroke design. This took the long-stroke concept to its extreme, creating engines with incredibly low speeds for maximum propulsive efficiency.
- RTA 52U, RTA 62U, RTA 72U
RTA-C/T/M Series: Specialized variants within the RTA family.
- C = Container ship application (optimized for high power).
- T = Tanker ship application (optimized for torque at low speed).
- M = Modified or modernized version.
- RTA 84C, RTA 84T, RTA 84M

Understanding Sulzer’s Model Numbering System:

Prefix Letters: Denote the engine type and technology.
- R = Crosshead (low-speed) engine.
- A, L, T, S, Z = Four-stroke engine designations.
Numbers: Almost always refer to the cylinder bore in centimeters for low-speed engines (e.g., RTA 84 has an 84 cm bore) or to displacement for smaller engines.
Suffix Letters: Indicate specific features or generations.
- D = Direct Reversible.
- H = High Output.
- M = Modified.
- U = Ultra-long stroke.
- L = Long-stroke or Low-speed.
- C/T = Application-specific (Container/Tanker).

Mitsubishi Marine Diesel Engines: Model Range

Model	Model	Model	Model	Model
45/75C	45/80D	45/115H	52/90D	52/105D
52/125H	60/135D	60/150H	37/88	37/88H
37LA	45L	45LA	45HA	52L
52LA	52HA	52LS	60L	60LA
60HA	60LS	75LS	50LS II	80LS II

Mitsubishi Heavy Industries (MHI) has been a major player in marine propulsion, particularly in the Asian market. Their engine models are known for robust construction and reliability. The naming convention is distinct and reveals the engine’s bore, stroke, and generation.

The models you’ve listed are primarily two-stroke, low-speed crosshead engines designed for direct propulsion of large ocean-going vessels like bulk carriers, tankers, and container ships.

Below is a breakdown of the model series.

Understanding the Numbering System: Bore/Stroke

The most common format (e.g., 45/75C) is key:

First Number (45): The cylinder bore in centimeters.
Second Number (75): The piston stroke in centimeters.
Suffix Letter (C): The engine series or design generation.

This Bore/Stroke ratio is critical. A higher stroke-to-bore ratio generally means a “longer-stroke” engine, which can run at slower speeds, improving propeller efficiency and reducing fuel consumption.

1. “C”, “D”, “H” Series: Early and Mid-Generation Engines

These letters represent successive generations of Mitsubishi’s engine design, each improving upon the last in terms of efficiency, power, and reliability.

45/75C: An engine with a 45 cm bore and 75 cm stroke from the “C” series.
45/80D | 52/90D | 52/105D | 60/135D: More advanced “D” series engines. The increasing stroke (80, 90, 105, 135) shows a move towards more efficient, slower-speed designs.
45/115H | 52/125H | 60/150H: The “H” (Heavy) series. These are significant upgrades, featuring even longer strokes and higher maximum pressure ratings for substantially improved fuel economy. They were highly competitive in their time.

2. “L”, “LA”, “HA”, “LS” Series: The Modern Long-Stroke Era

This group represents Mitsubishi’s shift towards the modern concept of long-stroke and super-long-stroke engines, designed for very low RPMs and optimum propeller efficiency.

“L” Series: The standard Long-stroke design.
- 52L, 60L
“LA” Series: An Advanced or improved version of the “L” series.
- 37LA, 45LA, 52LA, 60LA
“HA” Series: The High-output, Advanced version. These engines are designed to produce more power from the same bore size compared to the LA series.
- 45HA, 52HA, 60HA
“LS” Series: The Long-Stroke series. This is a clear designation for their most efficient models focused on low fuel consumption.
- 52LS, 60LS, 75LS
“LS II” Series: The second generation of the “LS” design, incorporating further refinements and technological improvements for even better performance and lower emissions.
- 50LS II, 80LS II (Note: 50LS II likely has a 50 cm bore, a very specific size for medium-sized vessels).

3. The 37mm Bore Group: A Smaller Workhorse

This family is built around a 37 cm bore, suitable for smaller cargo ships or as a smaller engine option.

37/88: The base model with an 88 cm stroke.
37/88H: The “H” series version of the same bore/stroke, with higher output.
37LA: The modern long-stroke, advanced version of the 37-bore engine.

Summary of Suffix Meanings:

C, D, H: Chronological series (H being newer than D, which is newer than C). H specifically denotes a “Heavy” or high-output design.
L: Long-stroke design for improved efficiency.
LA: Long-stroke, Advanced version.
HA: High-output, Advanced version.
LS: Long-Stroke (emphasis on maximum efficiency).
LS II: Second generation of the LS series.

Hanshin Marine Diesel Engines: Model Range

Model	Model	Model	Model	Model
LU 28	LU 32	LU 40	LU 46	LU 50
60 LU	EL 32	EL 40	EL 44	EL 46
EL 50A	LF 38	LF 50	LF 58

Hanshin Diesel Works, Ltd. is a renowned Japanese manufacturer specializing in medium-speed four-stroke diesel engines. Their engines are famously reliable, durable, and are a common sight powering generators, pump sets, and as auxiliary engines on ships of all sizes worldwide. They are also used for main propulsion in smaller vessels like tugs, fishing boats, and ferries.

The models you’ve listed represent their classic and modern engine lines. Hanshin’s naming convention is relatively straightforward, indicating the engine family and cylinder bore size.

Below is a breakdown of the model series.

1. LU Series: The Long-Standing Workhorse

The LU series is one of Hanshin’s most classic and widely recognized lines. These are simple, robust, naturally aspirated or turbocharged four-stroke engines known for their exceptional longevity and ease of maintenance. They are a prime choice for auxiliary generator sets.

Naming: “L” likely stands for the engine series, and “U” may indicate a specific design generation or type. The number refers to the cylinder bore in centimeters.
Models:
- LU 28 (28 cm bore)
- LU 32 (32 cm bore)
- LU 40 (40 cm bore)
- LU 46 (46 cm bore)
- LU 50 (50 cm bore)
- 60 LU (60 cm bore) – Note the slightly different word order.

2. EL Series: The Economical Long-Stroke Line

The EL series represents a more modern and efficient development from Hanshin. These engines are designed with a focus on fuel economy and higher performance, often featuring turbocharging and charge air cooling (aftercooling).

Naming: “E” almost certainly stands for Economical, reflecting its better fuel consumption. “L” is consistent with the series lineage. The number is the cylinder bore in centimeters. The “A” suffix in EL 50A indicates an advanced or improved version of the base EL 50 model.
Models:
- EL 32 (32 cm bore)
- EL 40 (40 cm bore)
- EL 44 (44 cm bore) – A less common bore size, filling a specific market niche.
- EL 46 (46 cm bore)
- EL 50A (50 cm bore, Advanced version)

3. LF Series: The Large Bore, High-Performance Line

The LF series consists of Hanshin’s largest and most powerful engines. These are heavy-duty, turbocharged and aftercooled four-stroke engines designed for high output. They are used for main propulsion on larger medium-sized vessels (like coasters and powerful tugs) and for large auxiliary generator sets on big ships.

Naming: “L” continues the series naming, and “F” likely denotes a Full or High-performance type. The number is the cylinder bore in centimeters.
Models:
- LF 38 (38 cm bore)
- LF 50 (50 cm bore)
- LF 58 (58 cm bore) – This is one of Hanshin’s largest bore sizes, representing their flagship model in this class.

Summary of Hanshin’s Naming Convention:

Prefix Letters:
- LU: Classic, general-purpose series. The backbone of the fleet.
- EL: Economical, modern series with improved fuel efficiency.
- LF: Full-performance, large-bore series for high power output.
Number: The cylinder bore in centimeters (e.g., 32 = 32 cm bore). This is the most important identifier for an engine’s size and power class.
Suffix Letter (e.g., A): Denotes a specific, improved version within that model family.

Key Characteristics of Hanshin Engines:

Type: Four-stroke, trunk-piston diesel engines.
Aspiration: Naturally aspirated (some older LU models) or Turbocharged and Aftercooled (most modern EL and LF models).
Applications: Primarily Marine Auxiliary Generators, but also used for main propulsion, pump drives, and stationary power plants.
Reputation: Known for incredible reliability, simple mechanical design, and ease of repair. They are the “go-to” engine for many shipowners who prioritize low lifecycle cost and operational simplicity over having the absolute highest power-to-weight ratio.

Other Marine Engine Brands

Wärtsilä (Finland)

Profile: Global leader in complete marine power systems, known for innovation and dual-fuel technology.

Key Characteristics:

Specialization: Four-stroke medium-speed engines, both diesel and dual-fuel (LNG, gas)
Technology Pioneer: Leader in smart marine technologies and energy efficiency
Range: Covers auxiliary power to main propulsion for all vessel types
Reputation: High technology, flexibility, and integrated systems (e.g., Wärtsilä NACOS platinums integrated bridge systems)