Diesel engines are greener than electric engines? In some cases, yes!


There has been a lot of recent publicity regarding the development of electric vehicles, and in addition, electric propulsion for marine use. Much of what is said highlights the reduced emissions from electric propulsion. It is true: electric engines can be cleaner than diesel or other petroleum engines. However, the media usually neglect an important fact, and that is that electric engines need to be charged somehow. That somehow usually means connecting to the power grid. Depending on where the engine is used, the carbon footprint of that electric engine can be much higher than that of an equivalent diesel engine. In regions where the bulk of electricity is produced by coal or other dirty fuels, that electric engine actually produces up to four times the amount of CO2 as a modern diesel engine.

The diesel fuel in 2015 is not the same as your grandfather’s diesel fuel. Modern diesel fuel is cleaner than ever before. All diesel emissions from vehicle use can be minimized and controlled, depending on the emission type. Right now, in the EU, there is some controversy regarding the fact that even though the introduction of ULSD reduced SOX emissions, there was an increase in particulate matter emissions (PM) and NOX emissions. However, PM can easily be reduced by filtration, and NOX can be reduced by the use of a SCR.

When compared to the use of electric propulsion, on the surface it can seem that the electric engine will produce fewer emissions at lower cost. Yet, when you compare the emissions and cost of charging, with the lower efficiency of electric engines (they are typically larger and heavier than diesels, with lower power output), the advantages of electric become less clear and straightforward. One additional problem that electric engines for marine use have faced is the limited range (electric cars don’t have the same issue as much on land): Limited range means limited places to charge. This fact has restricted the use of electrical engines to hybrids or coastal use.

MarineDiesel is in compliance with all emissions regulations in the EU and North America. Our engines can be used in regions with the strictest emissions standards and regulations (like the polar regions). Our research and development team are constantly modifying and improving the fuel efficiency of our engines, and reducing the emissions they produce.

If you want to learn more, there is an interesting discussion of the subject at





The VGT Series and Cadillac One: One thing in common


A little bit of trivia for a Monday morning:

The United States Presidential Limousine, dubbed Cadillac One, shares a common component with the MarineDiesel VGT Series of engines.

That common trait is that both use the Duramax 6.6L diesel engine block for their power. Though much of the limousine’s detail is secret, one thing that was publicly disclosed is the engine. Think about it for a minute. The vehicle has an enormous amount of weight from armor, security, and other devices. An engine block that is lightweight, yet powerful enough to move such a heavy vehicle is quite a useful thing to have.

This same power and light weight is even more important at sea. You can trust the fact that with MarineDiesel, you are getting the highest level of performance possible for your vessel.

Contact us today for a free, no obligation quotation.






Marine Maintenance and Diesel Engines



Maintenance of diesel engines is directly tied to life cycle and reliability. Modern marine engines are proven to perform well over long periods of time, provided that regular routine maintenance is performed.

One factor that is often neglected is the harshness of the marine environment. Salt is corrosive. Humidity causes corrosion. Fuel quality can vary greatly from one place to another. These issues help explain why most marine diesel engines have a much shorter time between overhauls than a similar engine that is installed on a truck or other type of vehicle.

Engine ratings also have a bearing in longevity. Engines that are rated for recreational use, for instance, are designed to be used in a recreational application. Use one of these engines in a heavy commercial setting, and problems are certain to ensue. Maintenance costs will certainly multiply exponentially. At MarineDiesel, we see this situation quite frequently. A potential customer will ask us for a quote on a commercial vessel, but they choose a cheaper engine that was rated for recreational use. Will the engine function? Certainly. Will the boat explode? Certainly not. However, the maintenance expense will be much higher, the life cycle will be much shorter, and the vessel performance will be lacking.

Is it still a good deal…?

All engines require periodic maintenance. As a manufacturer, we are in the “Front Lines” regarding maintenance issues. We see patterns as to what issues occur, not only in our engines, but in engines manufactured by competitors. The three most common maintenance issues that we see are often avoidable, and if diligently monitored, can greatly extend the service life of a marine engine (of any brand):

  1. Fuel quality: The number one (by far) problem we see is the use of bad fuel and neglected filter and polishing.
  2. Exhaust temperature: This is probably the number two issue. The biggest leading indicator of required maintenance.
  3. Smoke: Smoke tells you a lot, from a diagnostic perspective. It is nearly always an indication of required maintenance.

Though a bit of a cliche, engineers often state over and over again, “Read the manual”. The maintenance schedules we develop and publish are based on extensive testing results and are updated based on customer feedback, experiences, and warranty returns. In other words, the schedules are not simply made up out of thin air. If we recommend filter changes every 100 hours, there is absolutely a reason.

Bottom line: If maintenance and service schedules are followed, your engine will give you a far longer service life, and cost you far less money over the long term.



Intercooler Issues



The cooling system on diesel engines is one of the most critical systems on any engine. Indeed, on turbocharged engines in particular, large amounts of heat are generated by the combustion process and this heat needs to be dissipated in some manner.

Modern engines use an intercooler to dissipate this heat. An intercooler, strictly defined, is a device that serves to remove heat from a gas or fluid.

The intercooler interior on our VGT Series is pictured above (with the cover removed). In fact, since our VGT Series uses the same engine block on all models, one of the primary differences between our VGT 350 and VGT 500 is that the VGT 500, producing much more heat, requires a much larger intercooler than the VGT 350, which produces less heat. The dimensions of the engine are thus impacted (height). However, MarineDiesel has a fix for this situation, especially for installations in vessels with tight engine compartments. On these vessels, we offer a modification with the intercooler mounted forward, and vertically, thus reducing the overall engine height.

The intercooler on our engines is specifically engineered to provide the requisite amount of cooling. For engines in extreme climates, often additional cooling is required and many vessels have extra heat exchangers connected to the system.

Most intercoolers are relatively low-maintenance devices, however scaling can build up on the interior, and they must be periodically cleaned as detailed in the engine’s manual.



What is Common Rail?



If you read the marketing material put out by MarineDiesel or other engine manufacturers, you are likely to encounter the term “common rail” when the engines are described.

What exactly does common rail mean?

First off, all Marinediesel engines are common rail engines. There are a number of reasons behind this design, but mostly related to both efficiency and the need to comply with emissions regulations.

Common rail engines feature a fuel injection system that features all injectors connected along a single, high pressure (up to 30,000 psi) fuel line, controlled by the engine’s electronic system (ECU).

Older engines had the injectors fed individually at a continuous rate via a cam and though the timing was precise, it was not variable.

The electronic control of fuel supply and pressure provides better atomization of the fuel for combustion, resulting in lower emissions, reduced noise, and optimized engine efficiency with reduced fuel consumption.

Hence the virtual requirement for modern diesel engines to be designed using common rail fuel systems.

Of course, the drawback to common rail engines is that these increased pressures require extra vigilance in maintaining the maintenance schedules as required in your engine’s manual (whether for a MarineDiesel engine or the engine of any other manufacturer).



Best of 2014 – 10 Quickest Ways to Ruin your Diesel Engine



We wish all MarineDiesel customers a happy holiday season. Our factory will close from December 22 through January 5. For the balance of the year, we will be re-running our most popular articles from 2014, based on the number of visitors. We will start new daily articles in the New Year. We hope that you continue to find them interesting.

MarineDiesel prides itself on manufacturing engines of the highest quality, yet, sometimes we see things that make us scratch our heads and say, “What were they thinking?”

So, without further adieu, below is the list of ten things that we guarantee will kill your diesel engine as fast as a stick of dynamite:

  1. Not changing fuel filters, or, even worse, running without filters. (“But hey! Filters get EXPENSIVE”. Seriously, have you SEEN the fuel in Nigeria?)
  2. Not following engine break-in procedure
  3. Not changing air filters
  4. Not changing oil filters
  5. Not letting the engine warm up
  6. Not checking for leaks (at least until there is no oil left)
  7. Full throttle, 100% of the time
  8. Not starting the engine regularly. Sludge is never a good thing. (see below)
  9. Not checking fuel quality (Condensation? Nah… Not on this boat)
  10. Not checking temperatures. (You think that plastic bag blocking the strainer might cause overheating?)

BONUS: If you think that duct tape makes a permanent repair, no further comment is necessary.



History of the Diesel Engine



We came across this interesting video, produced by Shell in 1952, describing the history of the diesel engine up until that time. Though dated, the video gives a look back into the history of early diesel engines.

We hope you find it interesting, too.


10 Myths About Diesel



Yesterday’s article focused on 10 facts about diesel fuel and diesel engines. Today’s article will explore 10 common myths about diesel fuel and diesel engines. If you read or hear anything about the information below, just don’t believe it: It isn’t true:

  1. Diesel engines must idle a long time after starting. This is a statement that was once true, but no longer. Before common rail technology and modern electronic diesel engines existed, diesel engines needed to idle for a while both at startup and at shutdown. This was due to the nature of diesel combustion and the design of early turbochargers. Modern, electronic diesel engines do not require long warmup and cooldown times.
  2. You cannot use synthetic oil in a diesel engine. Pure hogwash. In fact, the recommended oil in MarineDiesel’s VGT Series of engines is synthetic. Why? It has a longer life cycle and resists higher temperatures and thermal breakdown better.
  3. Diesel engines are noisy. Again, this used to be true, but no longer. Though modern diesel engines can produce slightly more noise than gasoline engines, most manufacturers have greatly reduced the amount of noise produced. This is one area where MarineDiesel has put significant resources into R&D.
  4. Diesel’s don’t start well in cold weather. Not true. Inexpensive inline heaters are standard on modern diesel engines and they start just as easily as other engines in cold weather, sometimes better. Note, we are well-versed in cold weather operation, given our Scandinavian heritage. Our customers use our engines in some of the coldest climates on Earth, including Greenland and Russia, without problems.
  5. Turbochargers lag. Again, not true. There is a reason that we use VGT (Variable Geometry Turbocharger) turbochargers on our engines.
  6. Diesel fuel is dirty. Not true. As mentioned in yesterday’s article, ULSD is one of the cleanest fuels.
  7. Adding propane gives diesel a boost in power. False. Don’t. Ever. Do. This.
  8. Diesel maintenance is expensive. All marine engines require maintenance. Generally, over the life cycle of the engine, diesel engines are cheaper due to the longer life cycle. Maintaining filters, gaskets, and keeping to the maintenance schedule as detailed in your manual keep diesels running trouble free over the long term, often cheaper than other types of engines.
  9. Diesel engines are sluggish. Not true. Modern ECUs produce efficient combustion. The higher torque of a diesel means a much quicker response than with petrol.
  10. Most engine wear on marine diesel engines occurs when operating at WOT. Not true. Most wear occurs at startup with rapid increases in throttle.


10 Facts About Diesel



There are many myths and misconceptions in the marketplace regarding diesel fuel and diesel engines. Indeed, the debates can be endless, and every engineer and naval architect has their own beliefs. Some may be true, while others are no more than mere wive’s tales. Today’s article discusses some interesting facts about diesel fuel and diesel engines. Tomorrow’s article will address some of the myths.

  1. Diesel fuel was named after the diesel engine. NOT the man who invented the engine (Rudolf Diesel)
  2. Diesel fuel, unless further refined, is a high pollution fuel. Further refining, under emissions regulations, has produced Ultra Low Sulphur Diesel (ULSD), which is one of the cleanest fuels in the market. Thus, modern diesel fuel is usually cleaner than the gasoline with which it is often compared.
  3. Diesel engines are always more fuel efficient than gasoline (petrol) engines.
  4. Diesel does not evaporate (as does gasoline), but it does degrade more quickly over time.
  5. Diesel engines are more durable and have a longer life span than gasoline engines.
  6. Diesel engines require more maintenance in the marine environment than gasoline engines.
  7. Diesel engines tend to be more expensive at purchase than gasoline engines (though the longer life cycle means that they are usually cheaper over the long term).
  8. Diesel engines produce more heat than gasoline engines. The nature of diesel fuel means that it has a BTU output, and thus produces more heat.
  9. Diesel fuel is usually the same price or cheaper (even ULSD) than gasoline at the refinery. The price differentials are usually more related to local taxation, rather than the cost of production.
  10. Biodiesel is still diesel. Though it is refined from vegetable products, rather than petroleum, biodiesel still must meet strict standards for quality and energy content. Nearly all marine engine manufacturers allow the use of biodiesel within their warranties.




What is Marinization?



What is marinization?

A diesel is a diesel, right? It should work just fine whether you use it in a boat or a car.

This question occasionally comes up in inquiries to our parts department.

In theory, at least, any diesel engine should operate on any vehicle, land or sea. However, in the years we have been in the marine business, we have never seen one of these independent project come to a successful fruition. The normal scenario is that someone is either given, or has picked up very cheap, an old diesel automobile or truck engine, and they come to us when they cannot get it working.

Marinization is the engineering and manufacturing of engines specifically for marine use.

What are the differences between marine and land engines? There are many. However, the following systems are nearly always different: Cooling, exhaust, and gearbox.

Marine engines need to be liquid cooled. That means that they use a heat exchanger instead of a radiator. As has been written many times before on this blog, heat is an engine’s worst enemy, and the heat produced by combustion must be dispersed effectively in some manner.

As to exhaust, engines used on land typically use a dry exhaust system. Try this on the water and you will have a very noisy engine, indeed. A big issue with wet exhaust systems is that they typically require modified cylinder heads in order to function properly. That old school bus engine most certainly would require new cylinder heads.

Transmissions, or gearboxes, are another issue. We refer back to the old school bus engine. Though you might save a little on the engine, you will need a marine gearbox with proper ratio in order to use that engine on the water. Gear ratios for marine engines are substantially different than on land.

Electronics and electrical systems are also substantially different on marine engines. Something often overlooked is the need for a new control panel, since all of the gauges will be different. Wiring suitable to the marine environment is also necessary. Add in the fact that if the engine to be marinized is electronic, the ECU programming will be completely different. This problem can become extremely expensive to correct, and normally cannot be done by the average person or mechanic.

This brings us to the environment, in general. Marinized engines use components that are manufactured from non-corrosive metals and alloys. Engines used on land are not.

When all of the above is added up in the decision making process, that bargain engine most likely will not turn out to be as big of a bargain as it may seem. In our experience, nearly every one of these projects has resulted in very expensive failures.

Marinediesel has spent the money in properly engineering the marinization of our engines. We have already made the mistakes. We have engineered a bonafide marine engine, suitable for use on boats.

That is the definition of marinization and a very brief explanation about the steps necessary to accomplish the goal of diesel use on water.