515 Kilograms


515 Kilograms. That weight is the equivalent of:

  • An average adult polar bear
  • 1.1 times the weight of a grand piano
  • 30% of the weight of an average sized sedan
  • About 10% of the weight of an adult Tyrannosaurus Rex
  • 12 times the weight of a toilet
  • The weight of MarineDiesel’s VGT Series of marine engines

MarineDiesel manufactures the lightest, most compact, most powerful marine engines in their class. No competitors even come close. Though the comparison above is somewhat lighthearted, vessel displacement is a highly critical factor in vessel performance, and MarineDiesel leads the way in high power at low weight.







Smaller Engines: Lighter, more powerful, and more efficient


Engine development and research is a constant, ongoing process. MarineDiesel tirelessly continues to research into ways to make our engines more efficient, more powerful, lighter, and cleaner than any of our competitors. We already manufacture the world’s lightest and most powerful marine engine in our class. But we will not stop there, resting on our laurels. No, we continue to try and always make our products better.

In the upcoming year, expect to see new and more innovative products from MarineDiesel. The following points highlight the direction that we believe the industry is headed:

  1. Engines will continue to get more powerful. Turbocharger research, and research into combustion mean that engines have progressively gotten much smaller over the last 20 years of our existence. We believe that trend will continue.
  2. Engines will become even more fuel efficient. We recently were involved in a repowering project, replacing some Cummins engines that were manufactured in the 1970’s. Our modern engines consumed over 45 g/kWh less fuel than the legacy engines (which were fuel efficient for their time). We are certain that this trend will continue.
  3. Diesel engines will become cleaner, as will diesel fuel. The emissions environment is continually changing. Regulations typically are updated to take effect years in the future. These ongoing trends are a certainty.
  4. Alternative fuel will continue to be a priority. We are already converting engines to LPG and CNG. We are researching other alternative fuel sources.
  5. Engines will continue to become smaller. We are looking at many different blocks, power ranges, and displacements for future engine models. Some are expected to be released before the end of this year.




Keep Calm and Get Torqued


For the last year or so, a popular meme has been making the rounds through Facebook, and so on.


This was originally based on a poster from the UK that was made during WWII, but never actually used. A few years ago, someone found it, and the image spread all over the Internet.


So in the spirit of perpetuating a modern legend (or irritation, depending on your viewpoint), here at MarineDiesel we invite everyone to Keep Calm and Get Torqued.


Because the engines you have been using are weak. They don’t have the power.

Because the MarineDiesel VGT Series gives your vessel the highest level of torque, at the lowest weight, in the market today.

Because you demand high performance, at a reasonable price.

Because you should never settle for second best.



Multi-engine Installations



The picture above is an example of a triple engine installation MarineDiesel completed. Though the vast majority of our marine projects involve single or twin engine installations, we occasionally receive requests to power triple or even quadruple engine projects.

Indeed, as is evident in the photo above, engine compartments are often very limited in the amount of available space, and the compact size of the MarineDiesel V-8 engines means that our engines are often the only engine that will fit in some engine compartments.

Triple installations are usually more expensive than twin installations of higher horsepower engines, and there are other challenges as well, particularly on vessels that use propellers for propulsion. On these vessels, the nature of propellers means that vessels will have a tendency to “pull” in one direction of the other, due to the torsion of the propellers themselves.

However, a triple installation also offers additional redundancy, and normally lower weight than twin installations with larger engines.

So, which is preferable?

Normally the decision comes down to cost, though weight and space constraints also have an impact.

Nonetheless, the compact power of MarineDiesel engines means that multi-engine installations are far less uncertain regarding performance and are a cost effective alternative to providing high power in a limited space.

!cid_004a01c483cb$d06b28e0$6401a8c0@peter9rruh9dq2 (2)




Vessel Performance Problems – Who’s to Blame?



Designing high performance vessels is both an art and a science. Performance is one of those terms that can be defined in many different ways. However, when dealing with vessel design, performance is measured in terms of a customer’s expectations when a boat is designed. On recreational boats, built by large yards as a production run or as a specific model, performance means a standard that can be advertised to potential buyers. On military, commercial, or government service boats, performance is strictly defined in terms of expected speed, vessel load, and vessel use.

So, what happens when a boat is built and it does not perform up to expectations?

Enter the blame game.

  • The yard will blame the engine manufacturer.
  • The engine manufacturer will blame the propeller manufacturer.
  • The propeller manufacturer will blame the yard.
  • The yard will blame the naval architect.
  • The naval architect will then say that the customer’s demands were not realistic.

A cycle that is common, and usually is completely unproductive when solving the problem: WHY is the boat not performing?

Vessel design is a question of balance and the laws of physics. Numbers do not lie, and the laws of physics apply to everyone. What happened?

In our experience, the vast majority of performance issues are related to lack of communication between all of the different manufacturers of the vessel systems. In general, the following items are performance critical:

Vessel Weight / Displacement. This is the most common problem. It is either calculated incorrectly, or different materials were used than specified in the design (usually for cost reasons). Sometimes, it is not the yard’s fault. The vessel owner will often make changes after construction was started, sometimes ignoring the advice of the yard. This will put the builder in a delicate position of keeping the customer happy or achieving performance. It is not just with recreational vessels, either. MarineDiesel has seen many projects fail when a military commander decides to change the weaponry or vessel mission without any understanding of the physics involved, sometimes to comical results.

Bad Propeller / Propulsion Design. This is also not always the fault of the manufacturer. Propeller makers (or drive makers, or jet makers) can only make calculations based on the information that they are given. If they are given incorrect information, then the vessel performance will not be correct.

Bad Engine Selection. Engines cost money. Power costs money. As an engine manufacturer, the guarantees we make are based on the power of the engine we provide. So, if you buy 500 horsepower, we guarantee that the engine you buy will produce 500 horsepower. We do not make guarantees based on a project’s performance. Why not? How can we guarantee a performance level when we did not design or manufacture the hull, propeller, or drive? In some cases, a customer will try and save money by buying an engine that is under-powered for an application in order to save money. This returns us back to the laws of physics. There is no such thing as a free lunch.

Bad Hull Design. This is also quite common, especially on new, or prototype, hulls. On high speed or high performance vessels, design mistakes are often magnified, due to the increased forces on the hull at high speeds. We have seen such mistakes in water intakes, spray rails, steps (especially), foils, and simply bad designs. This is also why many yards insist on having designs that are proven, with other customers using the vessel.

It has been our experience that when vessels do not reach their required performance levels, it is usually a case of “all of the above” to varying degrees. It is important for vessel buyers to understand what they are buying and for everyone to be upfront and honest with all information. Unfortunately, in the competitive marketplace, costs are often the driving criterion on projects, and the ever present desire to reduce costs oftem is the real culprit, leading to bad decisions and poor engineering.


Tight spaces and tighter places



MarineDiesel engines are the lightest, and most compact, of any engine on the market in our class. That is indisputable fact.

Why does this matter?

Quite simply, MarineDiesel engines can fit into tight places that simply do not have the space for our larger competitors. On boats, especially RHIBs or small high speed craft, this is a very important product feature. RHIBs, in particular often have tiny engine compartments located immediately under the deck, with little excess room. The vessel pictured above is a recreational vessel with three engines. Engines made by our competitors would not only never fit in the limited space, but their extra weight would shift the LCG of the vessel considerably.

With catamarans or trimarans, a different problem emerges. The beam on each hull. Port or starbord, engine compartments are narrow, with little extra room.

This can be an issue in industrial applications, too. Our MDPT subsidiary is currently involved in a re-powering project involving armored vehicles. These vehicles are designed with precisely zero excess space, and the smaller, lighter MDPT engines make a big difference in vehicle performance and ease of operation.

In fact, the biggest problem we face in these cramped quarters is providing adequate cooling for the engines, whether on land or at sea. Engines produce a lot of heat, and that heat must be dissipated. Through years of experience, MarineDiesel has learned practices and techniques that provide adequate cooling, such as louver design, blowers, and engine placement.

To illustrate, see the ventilation diagram below:

A - Air should exit the engine bay and the upper section B – Air should enter the engine bay at the lower section

A – Air should exit the engine bay and the upper section
B – Air should enter the engine bay at the lower section





VGT Series: Five Best Vessel Types



MarineDiesel’s VGT Series of engines is light, powerful, and compact, making it an ideal choice for small, high performance vessels. However, as with any other engine maker, our engines are a better fit on some vessel types than on others. The five most common vessel types with our engines are listed below, with some reasons as to why the VGT Series is the best option:

  1. RHIBs: RHIB stands for Rigid Hull Inflatable Boat, and the VGT Series of engines is ideal for these vessels. Why? We are compact. Most RHIBs have very small engine compartments with little room for larger engines. We are powerful. Most RHIBs are used in situations where high speed and high performance are critical to mission success. Only the MarineDiesel VGT Series has the power and torque to excel in these applications. We are lightweight. One of the advantages of a RHIB design is the lighter weight over as traditional, non-inflatable hull. The VGT Series’  lighter weight than any competitor is a real advantage.
  2. Water Taxis: Water taxis tend to be lightweight, and operated continuously. The extended life-cycle of the VGT Series leaves recreational engines like Yanmar or Volvo Penta seriously lacking. The V configuration also means a tremendous reduction in vibration, with an increase in passenger comfort.
  3. Light Patrol Boats: MarineDiesel VGT Series are installed on many light patrol vessels (Under 15m). The high power, high and continuous torque, light weight, and easy maintenance give the MarineDiesel engines serious advantages over our competitors that design their engines for light, recreational use. The reliability provided by the VGT’s  long life cycle also means that missions are not disrupted by mechanical failure. The programmable NIRA ECU also provides mission specific capabilities that other engine makes cannot match.
  4. Light Commercial Boats: Many VGT engines are installed on ski boats, parasailing boats, and small passenger ferries. Long life cycle, fuel efficiency, and high power when needed are distinct advantages. The cost of ownership of VGT engines can be less than half the long term cost of ownership of competitors’ products, a direct impact on the bottom line.
  5. Rescue Boats: Rescue boats require high level of performance and reliability. They often operate under WOT conditions, in rough weather. The VGT Series is designed for such operations.





Eight considerations when choosing an engine, other than horsepower



There are two determinants that are primary in many engine buyer’s minds when choosing an engine: Horsepower and price. However, there are other factors, sometimes more important, that need to be taken into account when choosing an engine:

  1. Torque. Torque is often neglected in terms of considerations instead of horsepower, but it can actually be more important. This article from earlier this year explains the reasons why consideration of torque is so important.
  2. Fuel consumption. A difference in fuel consumption rates of only a few grams per kilowatthour equates to thousands of Euros per year in additional operating costs.
  3. Space. Engines must be able to fit into the space available.
  4. Weight. Heavier engines require more power to move. On boats, extra weight translates directly into extra displacement.
  5. Noise. This especially applies to gensets, but also on propulsion engines. Noise can become highly problematic in some applications.
  6. Life Cycle. Small differences in life cycle translate into thousands of Euros in additional costs over the life of the engine.
  7. Cost of spares. All spares are not created equally. Some brands have a reputation of having a high cost of spares.
  8. Maintenance network. Dealers and local service are important. That few thousand Euros saved at purchase is easily eaten up by additional downtime costs. Waiting weeks for spares to arrive from China gets very expensive, very quickly.