Marine diesel engines come in all sorts of shapes and sizes. In most cases, the type of diesel engine you choose depends on a variety of factors. These factors can range from price to preference in the specifications.
Irrespective of your knowledge about marine diesel engines, it can be a daunting task for a first timer to buy the right engine. As a result, you need to first learn about:
- The different types of diesel engines
- How they work
- The primary factors to look for in a suitable engine
An engine is an essential component that requires an informed decision-making process before making a purchase. Remember, making the wrong choice of an engine could be problematic in the future.
Hence, if you are interested in learning how to buy the right boat motor, keep reading.
What Are the Different Types of Boat Engines
Before getting into the details about these engines, here is a summary of the different types of diesel marine engines:
1. The Four-Stroke
Both large and medium merchant boats use this engine and get average speeds of up to 850 rpm.
It’s mostly preferred on machines without big head rooms like ferries because it is ideal for propulsion.
Marine experts claim that an engine needs four piston strokes to efficiently convert fuel to work.
When the pistons of the four-stroke move up then down twice, the crankshaft revolves two times. These stroke movements get referred to as compression, induction, and exhaust.
2. The Two-Stroke
Compared to the four-stroke, this engine is more powerful. It’s mostly preferred by people who own deep-sea ships which need a substantial power output for hauling.
Although its average speed is 100rpm, using it is cheaper as it can operate using heavy fuel oil.
The huge two-stroke engines are among the most powerful engines in the small marine boat category. Even though oil lubricates the crankshaft of the marine diesel engines, this engine doesn’t mix fuel or oil with air before the induction process.
In this engine type, the piston moves in an upward and downward movement in the cylinder. However, the movement only happens once and it’s the same for the crankshaft.
Gas Vs Diesel Engines
When buying a new boat or strategizing on how to re-power your current one, you might need to have a little debate by yourself. This debate should be on diesel vs gas as to which will fulfill your needs better.
There are some of us who have familiarized ourselves with diesel more than we have with gas engines. If you’re in this category, it’s possible that you think of diesel as smoke belchers. However, one thing you should know is that there has been a lot of evolution in the technology of diesel engines.
These changes have been mostly contributed by the EPA and the current mandates on minimized exhaust emissions and diesel fuel that’s low in sulfur.
The Key Factors to Consider in a Marine Diesel Motor
If you conclude that diesel is what you choose, here is an overview of the factors to consider before buying a new engine:
- Consider the size and weight of the engine
- Ensure you determine the amount of power you’ll require
- The trial models with a variety of power options
- Make sure you can easily access the service points of that engine
- Finally, choose a brand that offers professional services and parts that’s near you.
1. The Weight of the Engine
To improve the power to weight ratio, it is advisable to utilize strong but light material. Hence, a lighter engine contributes to this ratio.
Boats with improved volumetric efficiency have the turbocharging feature. Additionally, you’ll lose some efficiency in the engine exits through the exhaust. You can, however, recover this by utilizing exhaust gas to give the turbocharger enough power.
The differences in the engine’s weight are slowly changing as the technology evolves.
2. The Required Amount of Power
One of the major factors you must look into is the amount of power you’ll need. In most cases, this is usually something that’s narrowed down by your boat builder.
Do you want to know how? Then keep reading.
When you’re buying a new boat, it’s usually the best idea to run a sea trial first with the different options already installed. This helps you determine whether the boat’s standard package will meet your desires or you prefer a higher power setup.
However, when you’re taking a new boat for a sea trial, it doesn’t have all the usual cruise gear you normally carry around. Hence the boat is lighter than usual.
Since the weight to power ratio is crucial, more power is required to haul all the additional equipment. A 50 horsepower difference can make a big difference in the boat’s performance when heavy equipment or cargo gets included in the weight.
3. The Boat’s Maintenance
Nowadays most marine diesel engines have electronically controlled and computerized engines. This is due to the requirements set by the EPA.
The electronic features include regulators which control CO2 emissions via set tiers. For instance, Tier-3 standards apply to basically any recreational boat that’s diesel-powered regardless of the engine horsepower or size of the engine.
You might ask, so how is all this significant to me as an owner of a new engine?
Well, here is how.
Troubleshooting, maintenance and the incapability to DIY some traditional tasks are the big changes. If you go beyond the engine’s oil routine a lot and the maintenance of the cooling system, you’ll need both special training and tools to properly maintain your engine.
4. Choosing the Powerboat Propulsion
There are numerous options available for your powerboat propulsion. However, you can narrow them down to three categories based on your boat’s displacement. The three include
- Semi-displacement
- Displacement hull world cruiser
- Full planning hull.
The service availability and warranty limits play a big part in this. Additionally, the fuel economy is also a factor here. This is because these engines will give you the choice of primary propulsion compared to the auxiliary power.
Marine Diesel Engines
There are numerous types of marine diesel engines you can use for your boat motors. However, before settling on a motor, ensure it complies with the law to avoid any complications later. As far as compliance gets concerned, your choice should comply with both the US EPA and the International Maritime Organization requirements.
If you’re in need of a professional and reliable company that deals in commercial generators, boat motors, and industrial boat engines, then feel free to get in touch with us. Let us ensure that you get the best engine for your boat.
