Almost every boat owner and rider wants something that can run on the water faster and efficiently. Right? If you’re one of them and you want to know how to make your boat faster without mechanical modifications, then you’re in the right place.
How to make your boat faster? You can spend a few hours with your boat and shedding off some weight by removing unnecessary gear. Bottom repainting if necessary. This will get the engine running as fast as it was intended to. Also replacing propellers with an inch fewer pitch results in the engine turning up to about 200 RPM faster. And lastly, you could also jack the engine up if you are an outboard owner. This method is not as easy as the previous ones.
Figuring out how things work to make a boat run faster is your first step in meeting this goal. And this post is here you make you understand the various aspects involved. Some things will require you to get your hands dirty, and some are straightforward steps.
How Can You Make Your Boat Engine Faster Without Mechanical Modifications?
You can apply several ways to make the boat move at faster speeds, but it is a whole different story when it comes to making the engine faster. Thankfully, it is possible to rev up the powerplant beyond its current level, given the marine engines’ nature. We have broken it down for you if that is your need.
All the marine engines are designed to attain a specific maximum RPM range. However, it is essential to note that any modifications that you are willing to make on your engine to rev it higher will automatically void the manufacturer’s warranty. That explains why many people attempt to modify their engines to move faster only when the warranty has expired.
Another thing to remember is that the manufacturers designed the engine and the attaching parts with the specific RPM range in mind. Therefore, any modifications pose a significant risk for a breakdown. All changes are done at the owner’s risk. Your enjoyment as a result of the faster engine may be short-lived, but it could be worth it.
What Fast Fixes For a Faster Engine Do You Have To Do?
Here we will outline the less-risky ways you can apply to get the engine spinning faster. If you notice that your boat engine is not hitting its peak and performing to its full potential, the following three ways could be the solution you are looking for to make boat run faster. These ways include changing the propeller, shedding some weight from the boat, and jacking the boat up- in case of outboards.
Shedding Off Some Weight
Shedding off some weight from your boat is not only cost-free but also an effective way to make the engine faster. The only problem is that we tend to add more junk and equipment on the boat with years of use.
Moreover, the multiple layers of saturated coring or bottom paint also add to the boat’s weight. And this results in your boat weighing up to 20% more weight than it weighed when you first purchased approximately five years ago.
With this increased weight, you may also have noticed a change in the performance of the engine. The engine may have hit its peak of, say, 5000rpm when it was first launched, but now it only spins around 4500 rpm as it tries to overcome the extra weight.
To solve this, you can spend a few hours with your boat, removing gear, replacing saturated core areas, and soda-blasting an over-painted bottom. This will get the engine running as fast as it was intended to.
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Changing The Propellers
The following method you can apply to get the engine spinning at a higher RPM is changing the propellers. Generally, it is a tried and tested fact that changing the current propeller and replacing it with an inch fewer pitch results in the engine turning up to about 200 RPM faster.
Furthermore, you can gain more boat speed by swapping the propellers if the current one you are using is an aluminum prop. Those propellers made of stainless-steel do flex less than aluminum.
Therefore, trading out to get one will play a role in raising the boat’s overall speed. Remember that switching propellers do not directly affect the engine; instead, it increases your speed. So, if your ultimate goal is increasing the speed, you could put this into consideration.
Jacking Up The Engine
And lastly, you could also jack the engine up if you are an outboard owner. This method is not as easy as the previous ones. It will require you to pull off the engine from the boat, mount the jack plate onto the transom, and then finally mount the engine onto the jack plate.
You also have the option of vertically raising the engine to get an as much lower unit out of the water as possible. The less low unit will translate to less drag, which means that the engine will move faster, moving the boat at a quicker clip.
There are other methods that you can apply for a faster engine. However, they are at higher risk and will require mechanical modifications outside the scope of this article.
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How Do You Tweak Your Props To Make Your Boat More Faster Without Mechanical Modifications?
Many boaters desire to move their boats faster while burning less fuel. Well, you can now take this desire to the next level and actualize it. This may involve you shelling out some good money for that fuel additive or the latest hull coating.
The results may not be as significant, but for an average boater, the 10% improvement in the boat’s speed, which translates to approximately three knots, could go a long way.
However, it would be best if you focused on the investment return- the modifications you are making should produce an improvement that justifies the cost. So, before you start modifying anything, ensure you have an answer to that question.
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Is Your Boat Running On The Right Props?
Another thing is if you can tell whether your boat is running on the right props. Finding out will require time and effort, but it will be worth your while. The general rule of thumb concerning this topic is that the right prop allows the engine to spin at a speed that produces maximum horsepower and no more.
If you intend to find this hotspot, you can refer to the horsepower-output graph, and you will notice that the maximum horsepower occurred at only some specific data points in the RPM range. Below this, the engine is not making its full power, and above that, ten output usually declines dramatically in most cases.
To confirm that the gasoline engine has been mis-propped, you have to check with the tachometer. If your engine rating is 4800 RPM, and the reading on the tachometer is 5200 RPM, that means that you are losing efficiency and speed. This also means that you will most likely need more props.
The diesel engines are slightly different as they are governed. Therefore, their maximum RPM is either electronically or mechanically limited. The tachometer could indicate the engine at its RPM rating when it is not making total horsepower as it is not fully loaded.
To determine whether the prop on your diesel engine is the right one, you need to know the engine load. This is usually a trial and error method; run your boat and note the speed and rpm. Change the props with those of more cup or pitch and rerun it, recording the speed and rpm.
If the speed is more, repeat the process until it starts to drop. However, this method is very costly as it involves many props, runs, haulage, and wrench turning.
The electronic engines made the difference. Some of them offer the engine load data. With that number, you can take out your boat and run it up to WOT and check how close the number is to 100%. Most engines will not reach the threshold, but anything above 95% is acceptable.
Any engine should be well propped to achieve that desired threshold, whether they burn diesel or gasoline. This should be under real-world conditions, i.e., with people and all your stuff aboard, with the tanks being half-full.
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When Should You Change Your Props?
Props hardly change over time. Therefore, if you notice that your boat is not moving as fast as it should, do not look at the diameter or the pitch, but the stuff you keep adding abord and the growing green beard on your hull. But in rare instances, your boat may have the wrong props, and it is up to you to determine the right ones. Again, this is a costly process and a trial and error.
If the deficit in rpm and load is small, you are lucky as you can quickly correct that by adding a cup to the blades from the nearest prop shop. But if the deficit is significant, you will have to find a prop shop with loaner propellers inventory. This may be on the expensive side, but it will be a good value for your money in the long run.
However, remember that changing props will only result in small changes. Your 30-knot cruiser will not become a 35-knot cruiser; it could only move to be a 31.5 knots cruiser. With this, you should expect to hit that sweet spot. If that is not the case, even after switching the props, you could be causing damage the engine.
The three things that determine the engine’s propeller-turning speed are the gear’s marine reduction ratio, the pitch, and the propeller’s diameter. The only parameter you can change is the pitch, but that will not be a problem from this article. You should leave the rest to engineers and boat builders.
Highlighted above, How to make your boat faster? (without mechanical modifications), are the quick fixes and few modifications you can make on your boat for the best performance. With that in mind, you can attain the sweet spot of your boat and enjoy its full potential even after years of use.