Introduction
The invention of the boat has been one of the most significant creations contributing to human progress. From small ferries to giant ships, boats have transformed the way of transportation.
Earlier boats were small and had to be operated manually with the help of oars. Today the oars have been replaced with powerful marine diesel engines, but that has not been the case always.
In this blog, we will briefly discuss the history of boat engines. Further, we will discuss in detail about different engine types and their advantages and disadvantages.
You can directly jump to the section that interests you the most at the moment.
Brief History
Before the invention of the diesel engine, gasoline engines were the most preferred choice for watercraft. They offered the demanded balance for weight to-power ratio, the fuel expenses were less and the maintenance infrastructure was plentiful.
Then diesel engines were invented and it changed the whole game. Marine diesel engines were better at generating immense low-rpm torque, providing fuel efficiency, and reducing maintenance costs, thanks to the durable design.
But, the two-stroke marine diesel engine was out boarded. The mixture of oil in burning the fuel inside the piston created greater environmental issues. Thus, the four-stroke marine diesel engine became mainstream.
They became the powerful heart that pumps immense energy to the vehicle while still maintaining fuel efficiency and durability, alongside reducing environmental impacts.
Configurations of Diesel Engines in Boats
Fundamentally, there are three configurations for assembling a diesel engine into a boat:
- Outboard
- Inboard
- Stern drive
Let’s dive into the specifications of these off-highway marine diesel engine applications
Outboard
Engine Placement
In this configuration, the standalone propulsion system or the diesel engine is assembled outside a boat’s transom. As the engine is attached outside the transom it leaves ample space inside the boat allowing passengers to be seated comfortably.
Maintenance
The outwards assembly allows for effortless maintenance practices. An engine with a power range of up to 15 hp is affixed with clamps that can be removed as per convenience for maintenance and repairs.
Inboard
Engine Placement
This is a more sophisticated structure for engine placement. The diesel engine is located securely within the hull of the boat. Built for larger vessels, the internal mounting provides specific advantages in design and performance.
Maintenance
The fully isolated diesel engine is difficult to access in an inboard configuration, but it is easier to remove the whole unit for maintenance.
Stern drive
Engine Placement
A combination of the outboard and inboard configuration helps in forming the sterndrive engine placement. Here, the power source is placed inside while the propellor and drives are attached outside the transom.
Maintenance
Accessing the motor is limited but less difficult than a full inboard engine placement. Its service is usually focused on the u-joint, gimbal housing and bellows boots lying externally.
Different Engine Configurations
Gasoline and Diesel Engines
Now, we already know that gasoline engines have been prohibited from use as a result of increasing harmful environmental impacts. But, gasoline engines were the most preferred choice for small boats accounting for the balance of power to weight ratio, better acquisition and refuelling cost, and a plethora of maintenance infrastructure.
Modern marine diesel engines brought a revolution to the industry. They were better at everything compared to a gasoline engine and additionally also resolved the problem of high torque at lower rpm.
Gradually, diesel engines became a preferred choice for a majority of watercraft, but the two-stroke diesel engine also created environmental problems as it burned oil with the fuel.
Two Stroke and Four Stroke
The four-stroke engine combustion cycle was designed with a separate lubrication valve from the one that opened in the combustion chamber in a two-stroke diesel engine. Alongside that, a better liquid coolant system helped maintain optimum operational temperature for longer hauls.
Better and cleaner combustion, maintenance of optimum temperature and the legacy of roaring power made the four-stroke off-highway marine diesel engine a perfect partner for watercraft.
Here is a list of the pros and cons of different engine types for better understanding.
Gasoline
Pros
- Economical upfront investment
- Light in weight
- Market availability
- Effortless Maintenance
Cons
- Higher fuel consumption
- Limited torque
- Shorter lifespan
- Increased safety concerns
Diesel – 4-stroke
Pros
- Better fuel efficiency
- Higher torque
- Cleaner combustion
- Reliable durability
Cons
- Regular maintenance
- Higher initial investment
Why MVDE?
Choosing an engine for your watercraft concerns many primary questions such as the type of operation, horsepower needs, fuel availability, maintenance periods and much more.
At MVDE, we understand the dynamic needs of your boats and have designed a series of off-highway diesel engines that always ensure a dependable and powerful performance against every stride of the water. Connect with our team of experts who will guide you towards the best engine type suitable to your needs.
