Posted on 10 November 20198 February 2024 by abmarineservice — 1 Comment

To load batteries, battery separator

Charge the starter motor battery and the light mains battery simultaneously without being connected. Yes, that is possible!

You spent all day on the water and have made good use of all the conveniences the boat has to offer. The fridge is running, the lights are on, and you have had a good night’s sleep. The following morning, when you are about to set off for your next destination, you turn the ignition lock to start the engine, but then…

The familiar sound of a failing starter motor due to insufficient voltage. Sufficient power for lights and accessories is one of the first requirements when you venture on a long trip. But sufficient power is also needed to start the engine the next day.

Because the power requirements of the mains and the starting system are different, the best way to solve this problem is to use two separate batteries that suit the individual systems. The problem is caused by the fact that the mains is often used for a longer period of time and the starting system requires only a short jolt of power. Special start and traction accumulators are available for this purpose.

Even for smaller installations is the use of a separate light and start battery system recommended. While using power from the light battery, there is no connection with the start battery. The latter is therefore always fully charged and remains available for starting the engine. After which the batteries can be recharged by the generator of the engine.

After separating both power sources, they should also be charged separately.

After separating both power sources, they should also be charged separately.
To separate the batteries and charge them with the engine generator, use a battery separator, also called a diode bridge, to distribute the output voltage among the two batteries. Alternatively, use a separator relay that switches to the second battery when the first one is fully charged. Both parts can be found here.

A battery separator is a specially manufactured diode bridge that connects the second battery (the light battery) to the alternator while the engine is running. The relay is controlled by the so-called “D+” connection of the alternator and has a provision to prevent overloading of the alternator and the charge regulator.

A choice to make: battery separator or diode bridge?

The main advantage of a battery separator is the outright separation of the battery sets under all circumstances, so if one battery is flat, it can never draw current from the other battery. Think of two barrels of water. A separator conducts the charging current from the alternator or battery charger and distributes it to the battery sets. This is done through two or more diodes, which act like a “non-return valve” for the charging current: there is only one flow direction for the current; it cannot flow back.We carry a range of simple battery separators to set up a system as described. Always remember the voltage and required power that may run over the relay.

Rule of thumb is as follows:

70 AMPERE DIODE BRIDGE: for chargers and alternators up to 55 Amps maximum charging current.
120 AMPERE DIODE BRIDGE: for chargers and alternators from 60 to 90 Amps.
150 AMPERE DIODE BRIDGE: for chargers and alternators from 100 to 120 Amps

Please keep in mind that a diode always has a bridging voltage (threshold voltage) of 0.6 volt. It means that when using a 14V charging system, no more than 13.4 volts will run to the battery. This may cause a problem for older alternators. A separator fitted with a compensation diode prevents a voltage drop over the diode, so that the battery is charged with the correct voltage.

A battery separator will still allow charging the battery, even with a charger from the general 230V power mains. See the diagram for a simple set-up of a battery separator.

Take a quick look at a low-cost battery separator for your boat!

Posted on 8 November 20198 February 2024 by abmarineservice — 3 Comments

Dry and wet exhaust.

The difference between a wet and dry exhaust explained!
Compare a dry exhaust to the exhaust pipe of the car: a pipe with a flexible connecting piece on the exhaust manifold, discharging the exhaust gases directly to the outside air. A dry muffler is often required to muffle the noise. Cooling water from the engine is added to the exhaust system either externally or at a much later stage. The tubes and pipes are often made of steel to prevent them from melting due to the high temperature. It is a simple system, but with two major drawbacks: it emits intense heat of up to 600°C at the source, and it produces more noise.

Rather a wet exhaust?
What is a good alternative? That’s right, the much talked-about wet exhaust system. It is recognised by the manifold that is mounted on the engine. This is often custom-made from cast iron. It is also recognised by the freezer caps in the cooling channels. The heated cooling water in the engine is around 60-90°C when it leaves the engine, so it can be perfectly used to cool the 600°C exhaust gases. Water and gases are often not yet mixed in the first section of the exhaust pipe. That is to prevent the water from entering and blocking the gases from exiting the engine. Gases must be able to exit the engine smoothly so as not to compromise the engine performance. At a short distance from the engine, the gases and liquids come together and exit the engine.

The difference in temperature of a dry and wet exhaust is noticeable and has many advantages.

The noise of a wet exhaust is muffled by the water, but a rubber exhaust hose can also be used. This gives more flexibility and has a longer life span.

Various cooling systems

In simple terms, there are three types of cooling systems: 1. A system that pumps water straight from outside into the engine block by way of an impeller pump; 2. A separated system, often referred to as an intercooling / heat exchanger system, with coolant in the engine and an impeller pump pumping cooling water through a heat exchanger. 3. A keel cooling system, with cooling pipes containing coolant running underneath the boat. A wet exhaust is not possible in this system, unless an extra pump is installed.

From dry to wet? Convert the dry exhaust if you would like to experience the advantages of a wet exhaust system. Fully assembled exhaust pipes are available on the market. Or just add water to the dry exhaust, where only the first section is not cooled. Conversion may require a fair amount of money, but it is an easy job for the handy do-it-yourselfer and it will pay off in due course.
( wet exhaust system with waterlock and muffler).

A wet exhaust consists of the following components from start to finish:

A water inlet pipe underneath the boat with a shut-off valve to stop the supply during repairs or maintenance.
A seaweed filter to stop harmful material entering the impeller pump.
A suction pump on the engine (impeller or bilge water pump.
When conversing from keel cooling to intercooling: a heat exchanger with water-cooled exhaust manifold.
A water injection piece, which adds cooling water with an aerator past the exhaust manifold, to prevent the water from siphoning back into the engine when the engine stops.

Also, a so-called Waterlock is recommended when using a wet exhaust. A waterlock collects the water and pushes it upwards through the exhaust with the exhaust fumes by means of overpressure. A waterlock also muffles the noise, because it remains at water level. The gooseneck serves as an extra safety feature to prevent backflow of water when the engine is lower, as is the case in most sailboats. Installation of a muffler is still an extra option. A muffling and flexible exhaust hose can also be used for wet exhaust systems; it can be attached using stainless-steel hose clamps.

Looking for advice on your exhaust system? Please do not hesitate to contact us, or visit our website for various parts.

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Posted on 8 November 20192 February 2024 by abmarineservice — Leave a comment

A flexible engine set-up

Vibration-free sailing is for relaxation!

Ever made a lovely boat trip, but eased down on the throttle after a while because of all the noise? After all, for a stress-free yarn we want to be able to hear one another. A flexible engine set-up with engine supports will minimise any noise and vibration. But what is the basis of vibration-free (relaxed) sailing? The principle is simple: remove the fixed connection between the engine and the bedplate. This makes that vibration of the engine is felt throughout the boat. Allow the engine to float on its bedplate to get rid of the noise. But how is that done? Start at the base;

Why do engines vibrate?
Engines have internal parts that quickly move back and forth. It takes only milliseconds for the piston to be pushed down by an explosion and then back up again, driving the crankshaft at the same speed for a new compression stroke. Modern engine blocks are compact and lightweight thanks to a short piston stroke and aluminium construction. This has many advantages, such as saving space and lower production costs. However, due to its lightweight construction, vibrations are less attenuated and absorbed by the dead weight, and the shorter engine stroke also requires a higher RPM to keep running. And we know from experience that the further we open the throttle, the more noise we create.

Detached engine mount
All the more important to ensure a good and solid bedplate with soft engine mounts, which detach the engine from the bedplate, as it were. The principle is an engine mount as soft as possible, but still strong enough to carry the weight of the engine, the reverse clutch and a part of the propeller shaft.The softest possible rubber
The softness of rubber is expressed in SHORE with a hardness number. In addition, the letters A through to D determine the category of rubber, on which we will not elaborate in this article. SHORE 10 rubber is very soft, and the higher the number the firmer it becomes. A heavier engine also needs stronger rubber to make sure that the rubber is not squeezed out by its weight. Engine mounts are often SHORE 35 and up. It is a matter of finding soft rubber that is firm enough to support the engine. Hardness and quality of the rubber often determine the price and lifespan of the product. Good advice! It would be wise not to look at the price when purchasing engine mounts. Cheap engine mounts from other sectors (washing machine mounts) may be able to do the job, but are not always resistant to oil, grease and diesel fumes that we encounter in engine spaces.

Too soft?
If the engine mounts are too soft, sturdiness will be lost due to the pull and push movement of the propeller shaft and engine when manoeuvring. V-shaped engine mounts lock the engine in place under load due to their V shape. However, since the engine pushes itself against the rubber, it will also lose some of its muffling effect.

But what is the best solution
For optimal muffling, a combination of flat vibration isolators with a thrust bearing would be the best solution. A thrust bearing keeps the propeller shaft in place. It is a bearing that can absorb forces from any direction. It also hangs in rubber and is mounted between the reverse clutch and the propeller shaft. After installation, it has to be set exactly straight and level to prevent overloading of bearings and propeller shaft sleeves. Even better is to put a flexible (homokinetic) joint between the coupling and the shaft, so that even when under pressure and shifting, all parts can still be running stress-free.

Example of a homokinetic engine arrangement:
propeller shaft; brown
clamping hub; blue
thrust bearing; pink
homokinetic coupling; green
adapter flange; red
engine mount / vibration isolator; yellow

Advice
Looking for less vibration and more relaxation? In other words: a better engine set-up? We suggest you take a good look at the bedplate of your engine set-up and think about possible improvements. We advise to have this done in consultation with our experts. All engine and clutch makes require their own power calculations. Based on such data, we will be able to draw up a plan.

We supply arrangements for any brand, engine model and reverse clutch. Feel free to ask for your own smooth sailing.

Posted on 8 November 20198 February 2024 by abmarineservice — Leave a comment

Slime strings and clogged fuel filters.

Slime strings & clogged fuel filters.

Diesel bacteria: for those who are unfamiliar with this phenomenon, we can assure that prevention is better than cure. Anyone who has experienced it won’t forget any time soon. In less than no time, fuel filters or even complete pipes and pumps are clogged up and stop working due to long black flakes and brown strings. Say goodbye to your boat trip.

Diesel bacteria can be compared to algae in an aquarium. They mainly form on the bottom layer of water and diesel in the tank. Water is heavier than most fuels and will collect at the bottom of the tank. Because the intake or drain valve of the fuel pump is often in a higher position, the water can stay in the tank for a long period of time.

Bacteria in your diesel?

Like many fuels, diesel is a natural product and contains microbes. The right conservation and treatment will cause little or no problems with bacterial growth. But with the right breeding environment, such as water, they will multiply rapidly. Bacteria are always present in the fuel, but also in the outside air from where they can enter the tank through venting holes. Condensation and oxygen from outside, in combination with a malfunctioning water separator, makes a fuel tank the perfect breeding ground. Especially in water sports, the circulation speed of the fuel tank is not always the same.

aanbieding-delphi-296-dieselfilter-waterafscheider

Condensation as breeding ground

A fuel tank is usually mounted on the inside of the boat. Therefore, the tank cools down at night and warms up during the day. Oxygen that moves through the process of heating and cooling always contains moisture. Warm air that cools down forms drops of water as condensation to the tank wall.The water drips down and sinks to the bottom of the tank, below the diesel. Diesel has a lower specific gravity than water. A practical tip is to keep the air space above the fuel as small as possible. Always fill up the tank completely when you are planning not to use the boat for a lengthy period of time (use winter diesel before the winter break). After all, the less air exists at the upper inside part of the tank where oxygen and condensation can settle on the walls of the tank, the better. Warmth and humidity may be the perfect conditions for diesel bacteria to multiply rapidly, but they can also do their work during winter. For that reason is a clean and dry tank ventilation in the right place desirable.

Rain and waves

Also, the incorrect position of e.g. the tank filler cap or vent may quickly cause water to accumulate inside the tank. Things like rainwater that seeps through an outside air vent, or splashes of water that hit the deck and get into your tank, must be taken into consideration. Also remember the correct sealing of the diesel filler cap on the outside and periodically check the seals inside the cap.

Is this new?

The government has ordered that diesel must contain less sulphur than in the past. Burning sulphur is very damaging to the environment, but sulphur also stopped bacteria growth in diesel in the past. Moreover, since recently a few percent of biodiesel is added to the diesel. Biodiesel is extracted from vegetable products and is therefore gaining importance as the world’s oil reserves are dwindling. But biodiesel has also the ability to attract water quickly and contains a higher percentage of microbes.

What can be done about it?

If possible, check visually for water formation in the tank, like a large “bubble” of water at the bottom. Never checked or drained this before? In that case, this will be a good start. Does the problem recur frequently? Check what the cause could be as described above, e.g. a malfunction or a venting problem, etc. The supply pump that feeds the fuel to the engine often pumps the diesel in the tank several times around via the return line. In this way, the tank is often kept clean and filtered. A correct filter installation with a water separator is able to collect water from the tank. Since water is heavier than diesel, it is collected at the bottom of the glass. The glass should show clear diesel. If clouded, it would indicate contamination. Frequent contamination and hard to drain the tank? The solution may lie in an external pump unit that continuously circulates the diesel through a filter set and separates the water.

We welcome your comments or experiences!

Posted on 8 November 20191 December 2022 by abmarineservice — 2 Comments

How to replace a starter motor yourself, in 3 steps

How to replace a starter motor

A starter motor that is too slow, lacks power, or doesn’t do anything at all? Time to replace it. You can do this job perfectly well yourself. First of all, safety is of the essence. Make sure that the mass switch and/or the battery cable is disconnected. The starter motor is usually located near the crankshaft on the side of the flywheel housing.

How to replace a starter in 3 steps

Follow these 3 steps to replace a starter yourself: disconnect, dismantle and find.
Continue reading How to replace a starter motor yourself, in 3 steps

Author: abmarineservice