Pre-Season Preparation

With spring upon us and Easter only around the corner, its time to start preparing your boat for the season ahead.  Whether your boat has been winterised or stored throughout the winter months, there are a few things that you should ensure you do prior to using the boat once again.

The Top Tips for preparing your boat include:-

Change the fuel filter/fuel-water separator….
….if this wasn’t carried out back in the autumn.  Most engines are equipped with at least one fuel filter or fuel-water separator.  These filters should be changed to eliminate moisture and contaminants that are trapped in the filter.

Your boat should have been stored with the fuel tanks full….
….this helps to prevent moisture condensation in the fuel tank.  If this wasn’t the case, top them up now and add a fuel additive that will absorb any moisture that may have formed while the boat was stored.

Change the engine oil & oil filter….
….if this was’t carried out in the autumn.  Start the engine and allow it to come up to operating temperature before changing the engine oil and oil filter.  This not only allows for a better oil change, but also picks up moisture that many have condensed in the engine while not in use.  This moisture can then be removed with the old engine oil.  Many boats are designed to allow the oil to be removed through the dipstick tube.  This can only be accomplished by the use of an oil evacuation system.  As the engine oil is draining, loosen the oil filter using the proper filter wrench. Its a good idea to place a container under the filter to catch any oil that may drip as the filter is loosened.  Many oil filters are mounted vertically and can be removed easily if precautions are taken to prevent the filter from being tipped when it is removed from the engine bilge.  Other oil filters are mounted horizontally or even upside down.  These present a larger problem when they are removed.  For those filters, a catch pan must be placed under the filter to catch all of the used oil that drains from the filter.  Used motor oil is considered a carcinogen (can cause skin cancer if exposed over long periods of time).  Use caution and clean your hands often when working with any used motor oil.  As with all petroleum based products, proper disposal is very important.  Used oil and oil filters should be recycled or disposed of accordingly.  Never dispose of used oil and oil filters in the landfill.  This allows the used oil to soak into the ground and possibly contaminate the ground water.

 Change the lubricant in the outdrive or transmission….
….another job to be done if it wasn’t done in the autumn.  Drain the lubricant in the outdrive or transmission and replace with the new fluid.  Again, it may be necessary to place a drain pan under the outdrive to catch the used lubricant as it is drained.  If an evacuation system is available, it can be used to evacuate the used lubricant.  Some outdrives require the removal of the propeller to allow access to the drain plug.  It is a good idea to remove the propeller at this time and inspect the propeller hub, propeller shaft and splines and oil seal located behind the prop. With the fluid out of the outdrive, its a great time to pressure test the lower unit and inspect for signs of leaks or damage.  When installing the propeller, be sure to lubricate the prop shaft splines with quality marine grease.  This will help prevent wear and make prop removal much easier next time round.  Once again it is important to dispose of used lubricants properly.  Please refer to the owner’s manual for the re-fill instructions.

Lubricate all grease fittings
Normally, there are grease fittings located on the steering arm, shift and throttle linkages and outdrive pivot points.  Be sure to lubricate all of these points according to manufacturer recommendations.

Charge and re-install your battery
If your boat was stored with battery removed, place the battery on a slow charger to ensure that it is fully charged, and then re-install the battery.  This check will test the battery’s ability to hold a charge under a load, like when the engine is being started or when other heavy loads are placed on it.

If the transom drain plug was removed during storage, re-install it
There is nothing like the adrenaline rush you get when you discover the transom plug is out and you are trying to figure out how to get your boat back on the trailer before it comes to rest on the bottom!

Inspect your trailer
Make sure all trailer lights are operating properly.  Check the winch cable to strap and tie downs.  If there are signs of wear or damage, replace them.  Check the trailer coupler and safety chains.  Make sure the coupler is locking to the hitch ball and ensure that the safety chains are not damaged and can be attached to the tow vehicle easily.  Also, lubricate the wheel bearings on the trailer.  If the trailer is not equipped with grease hubs, the wheels should be removed and the bearings inspected and lubricated.

If you are unsure of the steps or requirements for the steps or requirements for the spring preparation of your boat, contact your local dealer.

Winterisation of Inboard Engines

When the nights are drawing in and the temperature is cooling off, it is time to start thinking about preparing your boat for storage during the winter months.

‘Winterising’ an engine is a key maintenance task for any boat owner.  Failure to do so could mean more work in the Spring and more expense.

Your local engineer will be able to advise you on the necessary tasks that need to be carried out to prepare your engine.  You should also find these listed in your Owner’s manual.  However, as a general rule, it is recommended that the following procedures should be carried out:-

  • Check the cooling fluid – Vital to protect the inside of your engine, it is recommended that the mixture is 50% water and 50% anti-freeze.  Ideally it should be replaced annually as overtime it loses it’s anti-corrosion properties.  Top it up to the maximum level in the heat exchanger.
  • Drain the engine oil and refill with new oil – Bring the engine up to temperature to ensure oil is hot.  Replace the oil filter.
  • Rinse seawater cooling circuit with freshwater  – Close the sea cock and disconnect the hose on the outlet side of the raw water pump.  Disconnect the cooling water discharge hose from the exhaust manifold or riser.  Run fresh water into the discharge hose to back-flush raw water passages and rinse out salt deposits.  You can extend the disconnected pump hose outside the boat or let the bilge pump handle the flush discharge.  Remove and rinse the impeller as anti-freeze can sometimes swell the rubber.  It is probably best to leave it out until spring, in a dry place, sheltered from light.
  • Close the engine air intake – To avoid moist air getting inside your engine, ensure you seal air inlets, crankcase and transmission breathers, exhaust outlets and tank vents by creating an airtight seal.  Making caps from plastic containers and then taping them into place is an ideal solution.
  • Drain the engine oil and refill with new oil  – Bring the engine up to temperature to ensure the oil is hot.  Replace the oil filter.
  • Release belts tension – Slacken the alternator adjuster to release the tension on the drive belt, helping to prolong the life of the belt.
  • Drain water lock – The less moisture the engine is exposed to, the less corrosion will occur.
  • Dry the boat’s bilge under the engine -This is a mucky job but well worth doing to avoid leaving a lot of moisture which is liable to corrode the engine.
  • Spray the engine with a water-repellent product This will help safeguard against corrosion.
  • Fill Fuel Tank This will help avoid condensation.  Tighten the deck filler as water can puddle when the boat is ashore.

Dealing with Engine Temperature Problems

Temperature Gauge Problems Initially it is important to establish whether you have an overheating problem or a temperature gauge fault.  If you suspect a problem then it is a good idea to check the gauge against a thermometer that is known to be accurate.  The majority of marine thermostats open at 71°C and will be fully open at 82°C.  As a rule, a clean system, under moderate load should operate at the lower end of this range whilst a dirty system under a full load might operate in the upper range.  Anything outside this is abnormal and should be investigated.

Overcooling Whilst the most common problem is the engine overheating, the opposite can also happen and lead to long term problems.  A thermostat should have excess cooling capacity.  This compensates for the inevitable decrease in cooling capacity that results from the normal gradual build-up of dirt on the heat transfer surfaces.  A thermostat is fitted to avoid an over cooling problem in a clean, new system.  If there is a problem, quite simply, the thermostat is not working properly.  Ensure that it is of the right type and properly installed.  Do not assume that just because it fits it will function correctly.  There is a lot more to thermostat design than is often realised, so make sure that the thermostat functions properly by immersing it in hot water of known temperature.  The easiest way is to use a pan of water on a stove with an accurate thermometer.  Hold the thermostat by the flange with a pair of pliers and do not let either thermostat or thermometer rest against the bottom of the pan. The thermostat should open at the temperature marked on it and be fully open approximately 20°C higher.  Malfunctioning thermostats cannot be repaired, they must be replaced.

Overheating Overheating problems can be categorised into two basic problems that either alone or in combination with one another, will create overheating:-

Lack of Raw Water Flow Lack of raw water flow will show up as an excessive increase of the raw water temperature as the raw water passes through the cooling system.  Normal temperature increase varies between different engine models but is usually in the range of 40-60°F.  In other words, if incoming raw water temperature is 110°F, the outgoing water passing through the exhaust elbows will be in the range of 110-130°F. This will create surface temperatures on the elbow that will  be warm but not excessively hot.  So the easiest wasy to identify a raw water problem is to check whether or not the engine overheating is combined with excessive temperatures on the outlet side of the raw water system.

If the raw water side is to blame there could be three basic reasons:-

1) Pump Problems The most common pump used today is the rubber impeller pump.  The impeller in this pump must never be run dry or it will be ruined.  Eventually this impeller will also lose some of it’s flexibility due to old age and capacity.  To be on the safe side,  it is recommended that the impeller is replaced annually.  If the impeller is damaged with blades missing, make sure that you find the missing blades.  They could be stuck downstream from the pump interfering with proper flow.  If the raw water pump is belt driven, make sure that the belt has the correct tension.

2) Restrictions on Outlet Side of Raw Water Pump These restrictions are often in the form of raw water debris accumulating on the inlet side of oil coolers and heat exchangers.  Always check the units closest to the pump first and work downstream.

3) Exhaust Elbow Restriction Over time, problems with rust build up in the exhaust elbows may develop.  Many exhaust elbows have several small holes in the area where the raw water enters the exhaust pipe.  The orifices are designed to ensure proper water distribution at this point.  Unfortunately, because of their small diameter they tend to get clogged with the rust particles that a raw-water cooled elbow gives off.  Eventually, an exhaust elbow may get completely plugged up preventing raw water from entering the exhaust pipe and thereby creating a fire hazard.  In an in-line engine with a single exhaust elbow, this complete blockage will automatically cause engine overheating before the exhaust overheats.  This will signal a problem before a fire hazard develops.  In a V-type  engine however, the situation is more dangerous if one elbow becomes blocked,  In this case, sufficient raw water may be able to exit through the open elbow to keep enough raw water flowing through the engine heat exchanger,  The engine may not overheat but the blocked elbow and matching exhaust manifold and exhaust pipe could burn and be destroyed.  It is recommended that you periodically during the season feel the exhaust elbows to make sure that they stay at a normal temperature. Clean or replace these elbows before they cause further damage.  Periodic flushing of the engine with fresh water will help minimise these problems.

Lack of Fresh Water Flow Lack of fresh water flow will show up as an increase in the temperature difference between in and outlet of heat exchanger.  Most modern engines have a flow rate at a level where the temperature difference in and out on a block only system, will be in the range of 10-20°F.   If manifolds are included in the fresh water system adds another 10-20°F.  Most people find 60°C to be the approximate maximum temperature that they can leave their hand on without discomfort.  Since fresh water temperatures normally are above 71°C, it is not practical to check this difference without special equipment.

Be careful when dealing with a suspected temperature problem, the cooling system contains hot liquid held under pressure

Choosing the right battery…

With the introduction of higher output alternators and electronic  charge Xsplitters charging systems on boats have vastly improved.  To benefit fully from a decrease in recharge time and longer runtime the correct battery choice should be made.  When making a battery purchase you need to consider – Battery life expectancy (how often is it to be used/number of cycles~), depth of discharge (how much power is required for each use?), level of safety required (spillage and gas risk – sealed vs not sealed) and finally level of maintenance (top ups or maintenance free)

A quick guide is as follows:-

The FLA (Flooded Lead Acid) – Number of cycles is 100, depth of discharge is 50% and is not sealed or maintenance free.  It can be used for moderate duty, suitable for leisure & sailing boats.  The SFL (Sealed Lead Acid)  – Number of cycles is 200, depth of discharge is 60% and is sealed and maintenance free.  It has combined starting & deep cycling capability for motor boats & yachts.  The SDC (Flooded Semi Traction) – Number of cycles is 300, depth of dishcarge is 70% and is not sealed and maintenance free.  It is a heavy duty battery ideal for hir boats, workboats, live-aboards and ocean-going yachts.  The AGM (AGM Long Life) – Number of cycles is 300, depth of discharge is 70% and is sealed and maintenance free.  It has a longer life and deep cycle capability or motor boats, yachts and narrowboats.  The ADC (AGM Deep Cycle) – Number of cycles is 400, depth of dsicharge is 75% and is sealed and maintenance free.  It has extra deep cycle capability for hire boats, work boats, live-aboards and ocean-going yachts.  Finally the SGEL (GEL Ultra Deep Cycle) – Number of cycles is 500, depth of discharge is 80% and is sealed and maintenance free.  It has an ultra deep cycle & long life for ocean-going yachts & continuous live-aboard use.

For information on batteries from leading brands such as Leoch, Victron & Haze, please click here.

Why Waste Engine Heat – You’ve paid for it!

Turn your engine’s waste heat into useful domestic hot water with a C-Warm Calorifier.  Made in the UK and fitted as standard by leading UK and European boat builders, C-Warm heaters are designed for use at system pressure up to 3 bar (44 psi).  Maximum recommended pump cut-out pressure in 2.5 bar (36 psi).

Heating time from cold is approximately 20 to 30 minutes for a full tank of hot water.  Useful amounts of hot water are available within a few minutes of starting the engine.

Polyurethane-insulated for high heat retention, C-Warm heaters are available in stock sizes from 18 to 78 litres (4  to 16 gallons) with a choice of installation and control accessories.

Calorifiers and Water Storage – What’s the difference?

NONE – ‘Calorifier’ is a word borrowed from industrial process heating, meaning a water vessel containing a heat exchanger (such as a coiled pipe)  though which steam or hot water passes, giving up its heat to the water contained in the vessel.

For more information on the different models that we supply, please click here.

Pump Flow Rates & Pressures

Liquid flow rate and pressure are the basic measures of pump performance.  Flow rate is commonly measured in litres per second, per minute or per hour  or sometimes in cubic metres per hourPressure is commonly measured in bar (1 bar is equal to standard atmospheric pressure at sea level, or 1kg per square centimetre, or 14.6lb per square inch (psi).

Head is sometimes used as a convenient alternative to pressure.  Commonly expressed in metres or feet, head is the vertical height difference between the liquid supply and discharge levels.  A vertical column of water 10 metres high has a pressure of 1 bar (above atmospheric pressure) at it’s base.  A pump able to deliver water from ground level to an elevation of 10m is working against a ‘static head’ of 10m.

Water flowing though a pipe loses energy through friction at the pipe wall.  The loss of energy appears as a pressure loss in the pipe.  The pressure loss can be expressed as an equivalent head (‘dynamic head’).

Pipe friction losses may be negliable, or they may be substantial, depending on flow rate, pipe length and internal diameter (bore), and configuration.  To minimise pipe friction losses, keep inlet and discharge pipework as short and straight as possible.  Use the pump manufacturer’s recommended pipe size.  As a general rule, the pipework bore should be at least as large as the diameter of the ports on the pump.  If the pipework is very long or convoluted, use pipe of larger bore.

Monitoring The Engine Oil Pressure

The circulation of the lubricating oil around the engine has quite rightly been likened to the human blood circulation system.  The oil is pumped from the sump through the filter and into the bore holes leading to the main bearings on the crankshaft.  After leaving these main bearings, the oil flow is divided.  Part of it flows across the crankshaft to the connecting rod bearings and the piston bolts before being recycled, while another part lubricates the bearing faces of the cylinder through a centrifugal effect.

The remainder of the oil passes through boreholes to the engine cylinder head, where it provides lubrication for the camshaft, the rocker shaft and valve slide mechanisms, before returning to the sump.  The main function of the engine oil is to lubricate.  Ideally, the film of oil would be so homogenous that there would be no contact between the metal surfaces to the bearings.  Unfortunately, this ideal situation is interrupted whenever it occurs by the engine being switched off.  The film disperses, leaving no protective film between the journal pins and the bearing shells.  When the engine is started from cold, considerable wear can be caused.  At other points, for example at the contact surfaces of the cylinders, the lubricating film is little more than partial, with the result that wear can also be caused here.  This brings us to the second main function of the lubricating oil, namely the removal of all abrasion particles and impurities from the bearings.  These particles are usually minute metal chippings from the bearings themselves or the contact surfaces, while the impurities are normally combustion residues that have found their way into the crankcase as result of a lack of tightness of the piston rings.  The particles and the impurities are removed at the oil filter, so that the oil flowing around the lubricating points is always clean.  This also means that the oil filter will have to be replaced at regular intervals, as otherwise the excess pressure in the filter will cause an overflow valve to open and the unfiltered oil will be returned through a bypass valve to the bearings.  Furthermore, this cannot be detected at the oil pressure gauge.

In recent years, the lubricating oil has taken on an increasingly important third function – that of cooling.  In modern engines, as much as 15% of the heat is generated can be dissipated by the lubricating oil.

It is clear that such an important circuit requires an efficient monitoring system.  In some cases it is sufficient for the oil pressure to be monitored by means of a low oil pressure switch.  However, it is generally advised that a pressure gauge is fitted, or alternatively, and an even better solution is to fit a combination of a warning contact and gauge.  As the pressure builds up the problem is revealed by the gauge, which will give a good indication of the general state of the engine.  The oil pressure is usually measured through a drilled hole in the engine block and through which the oil is pumped from the bearings.  If there is any bearing damage in the vicinity of the crankshaft, the resistance is reduced and more oil flows across the crankshaft.  This has the effect of lowering the pressure at the measuring point.  The oil pressure will also fall if too much oil flows out of the cylinder head as a result of a detective bearing.  These are, of course, extreme cases which are fortunately exceptions rather than a rule.  There are also a number of other causes for a sudden drop in the oil pressure, if you have any concerns it is best to contact your local engineer to investigate further.

Technical Questions Answered…

Why is there a lot of noise and vibration coming though the boat, particularly from the stern end?
A common cause of noise and vibration through the boat from the stern is a worn cutlass bearing.   The cutlass bearing, which supports the shaft, can be found inside the p-bracket or stern tube, depending on design.  The shaft is prevented from damage as it spins inside the cutlass.  The most common cutlass bearing comprises a grooved rubber centre surrounded by a brass shell.  Also available are fibreglass and phenolic types.  The shaft should be a snug fit through the cutlass.  Over time as the bearing’s internal surface wears down against the shaft, additional space is created inside the bearing allowing for excess movement by the shaft. This movement causes noise and vibration through the vessel. Unfortunately, the only way to resolve this issue is to replace the bearing.

How do I replace my gland packing and how do I know what type to use?
Gland packing is used to make a water tight seal around the shaft at the inboard end.  There are two main types of gland packing available, PTFE (white) and Graphite (grey).  Basically, Graphite packing should not be used in saltwater; however the PTFE version can be used in all water types.  Occasionally, grease impregnated flax is also used.

To replace the gland packing, the first thing you need to do is take off the stuffing box and remove the existing packing, taking note of how many turns of packing there are around the shaft. You must now clean the stuffing box before re-packing it.  If you have a water-fed gland, this is simple and a quick wipe with a damp cloth will do the trick.  However, a grease-fed gland will require more thorough cleaning.  To re-pack the gland, wind the packing around the shaft, slightly overlapping and cut through using a sharp blade at a 45° angle which makes a better seal than a straight cut.  Repeat the same number of turns of packing to what you removed.  The seams of each piece needs to be staggered against the next, thus creating a water tight seal.   Reassemble and tighten the gland.

How often should I replace my anti-freeze?
Antifreeze is important – not only does it protect your engine from frost & ice damage, it is also a good summer coolant as it will protect all areas of the engine’s cooling system against rust and corrosion, so is best used all year round.

Antifreeze should be mixed with water, in a 50-50 ratio.  We would recommend a good quality anti-freeze is used; an Ethylene Glycol based product is best.

All antifreeze can degrade over a period of time, thus its effectiveness is reduced and the level of protection against frost damage is also decreased.  We suggest changing the antifreeze every two years, however it’s always best to check its concentration on an annual basis.

Should I change the engine oil before the winter or in the spring?
During the summer season whilst your engine is running potential harmful bi-products are produced from the combustion process which can build up in the engine oil.  Therefore we recommend changing your engine oil and filters before the winter lay-up reducing the risk of internal surface damage from prolonged exposure to these nasties.

Should I worry about the new type of diesel?
No….don’t worry, just be aware…
Recent legislation has led to a change of fuel used on the inland waterways.  The new fuel must contain no more than 10 milligrams of sulphur per kilogram of fuel and can contain up to 7% bio diesel.  Diesel bug is especially fond of bio fuels so this 7% addition can increase the likelihood of encountering issues in your fuel system. Protecting your fuel against diesel bug is therefore even more important. Water in the fuel is the number one cause of contamination where condensation collects at the bottom of the tank, filling your tank before leaving it over the winter is the best way to avoid this.  In addition to this draining off excess water from your tank and separator filter is a good way to ensure you have as little water in the tank as possible before leaving the boat over winter.

In older engines it is a good idea to keep an eye on fuel hoses and seals as these may be affected by the new additives.  Modern diesel engines, however, should not be affected.  It would be advisable to check with the manufacturer.

How do I maintain my batteries over the winter months?
It is advisable to take the time to properly maintain batteries prior to storing.  If you have wet acid or flooded type units they may require some attention.  This is a simple case of checking the distilled water level and topping up if necessary.  If your batteries are AGM or Sealed, i.e. don’t have removable caps then they will not require any maintenance.

When left for a prolonged period of time the cells can discharge to the point of no return, meaning you return to a costly replacement job in the spring.  To avoid this with small engine batteries that can be transported easily it is a good idea to take them home and store them in the garage where you can periodically top up their charge.  For bigger batteries or large banks of cells, isolate them from any potential load.  This is to reduce consumption from devices/appliances on board which can draw power even when not in use.  Over the course of the winter, in some cases this could be enough to flatten the batteries.  Charge the batteries occasionally to maintain the charge.

It is important to bear in mind when isolating or disconnecting batteries that this may affect the operation of the bilge pump.

The exterior of my engine is rusty.  What could be causing it and is it something which needs attention?
This may be an indication that there is a water leak from a pipe joint or from a gasket or casting.  This should be investigated and repaired as required. The corrosion will have to be cleaned off and the area primed and repainted.  It is easier to keep a check on a clean engine than a rusty one.

I read that most marine engine damage results from the failure to maintain the cooling system.  Can you give me some pointers on what to do?
Overheating is a common reason for engine breakdown and there can be a variety of causes.  Firstly you need to check if you have cooling water flowing through the system.  If this has stopped or the flow reduced you need to check the intake filter, impeller in the pump and also check that the first cooler before or after the pump is clear as weed can sometimes pass by the filter and restrict the flow.  Something that is often overlooked is the flow of the water after it leaves the heat exchanger/engine into the injection bend/mixer.  This is prone to corrosion that can restrict the water flow and cause the engine to overheat. If the water pump is getting on in years it may be that just changing the impeller will not be enough and the complete pump needs to be overhauled or replaced. It could be that you have a good flow of water but the heat is not being dissipated between the engine’s two cooling circuits due to scale building up around the heat exchanger or inside the engine’s internal capillaries causing a blockage. We recommend that the heat exchanger tube stack be cleaned every 200 hours.  As always good maintenance will help prevent overheating problems.

My boat is normally just used at weekends.  I have recently retired and am planning to cruise on her throughout the summer.   What steps should I take to prepare her for continuous use?
The first thing to consider is the existing systems/engine up to the heavier use, e.g. battery bank/charging system.  Whilst this may have been ok for a short trip, will it be suitable for continual use, including days where you might be moored up and not travelling?  It may be worth considering a larger battery bank and the means to charge the bigger bank as you can’t have one without the other.

It will also be very important that the engine and gearbox has a major service as this will probably be working harder in a month than it has done in the last few years put together.  This service should include oil and filter change, fuel system check and filter change; fan belts should be replaced as well as the water pump impeller.  It would also be prudent to replace all engine hoses and clips. Its all about limiting the potential problems before they arise.

It might be worth enlisting the help of an engineer for a few hours and discuss your intentions with them as they will be able to identify possible problem areas and suggest the best way to improve things.

Repowering Your Engine

Undoubtedly some of you will have old, tired engines that need some attention and often it comes down to a choice between rebuilding the existing unit or replacing it altogether.
In these situations it can be very easy to be tempted in to re-building an engine as this appears to be a cheaper/easier option than re-powering.  However, this can often prove to be a false economy, particularly with old raw-water cooled engines as more harm than good can be done through disassembly, due to a high level of internal corrosion.  This corrosion is a result of years of direct contact with salt water.  Engines built with wet cylinder liners can suffer similar issues even after a costly rebuild.  They can still be likely to suffer from oil emulsification.

If your current engine is always a problem to start, is low on power, constantly admits excessive smoke from the exhaust, leaks or uses a large quantity of oil, then its maybe time to think about replacing your engine altogether.  Particularly if your engine presents more than one of these symptoms.

The biggest advantage repowering has over rebuilding is you can be sure any or all of the above issues will be cured in one hit.  Additionally most modern diesels will be smoother running, quieter and more fuel efficient than engines of a previous generation.  And another bonus with a new engine is the availability of spare parts.  After all, sourcing parts for an older model can prove to be timely, difficult and expensive.

So….you’ve decided on the repowering option.  How do you go about choosing the correct engine for you?
An important consideration is your required horsepower (hp).  This is a personal preference, particularly in sailing vessels depending on how often you use the engine in your boat.  For example, if you mostly sail and only use the engine for manoeuvring in and out of port, you may feel inclined to have less hp than someone who wants to cruise at hull speed for sustained periods.  A rough guide to hp requirements in boats is 3-4hp per ton for racing yachts and 5hp per ton for cruising.  It is important to have a decent idea of the designed hull speed of your boat, as once you have reached hull speed it is impossible for displacement hulls, such as with sailing boats to go any faster, regardless of hp.  Another consideration is the size of prop that your vessel is able to swing.  There is a limit to the amount of hp any given size propeller can transfer to the water.  If prop and engine are imbalanced, i.e. the hp is too great for the diameter of prop, you’ll gain no benefit from the extra hp you have invested in.  The ideal scenario is to have an engine and propeller balanced to provide you with enough hp in the water to drive you comfortably at hull speed in ideal conditions with some power in reserve to deal with unfavourable winds and tides.

There are many other factors to consider when re-engining such as physical size of the engine and space available.  Typically a new engine will have a different footprint to the engine its replacing so it is important to have a plan as to what modifications may need to be made to your engine beds and surrounding space.  Whether you intend to install your engine yourself or have an engineer do it.  Installation issues, such as fuel & exhaust systems and whether they need to be replaced or not will be specific to the engine that you ultimately choose.  Ensure you discuss these issues with the relevant experts.

For more information about the Nanni Diesel range of engines, please click here.

New season…New fuel?

As we look forward to the new season and begin the usual preparations, this is an ideal time to perhaps consider the new EC Directive applicable to Ultra Low Sulphur Diesel (USLD) fuel which came into effect from 1st January 2011 and how it will affect us boat owners.

The Directive sets the environmental specifications to be applied to fuels for road vehicles and non-road mobile machinery (including inland waterway vessels when not at sea), agricultural and forestry tractors, and recreational craft when not at sea.  The standards refer to the sulphur content of gas oils intended for use by non-road mobile machinery and states that it must not exceed 10 milligrams per kilogram of fuel, meaning its virtually ‘sulphur free’.

While these regulations relate to inland shipping vessels and recreational craft operating on inland waterways, regulations for sea-going vessels are not changing.  These can still use the exsiting fuel, which contains 1000mg/kg of fuel.

The reduction of sulphur in itself will not harm existing engines, although some may find that they require an additive to make up for the loss of the lubricating effect.  However, this new fuel may contain up to 7% of a certain bio fuel, obtained from renewable sources known as FAME (Fatty Acid Methyl Ester).

So whilst the purpose of bio fuel is to reduce emissions, making it more environmentally friendly, there are factors to be considered, some of which can have potentially serious effects on engines, namely:-

  • This new fuel has higher water content which encourages more fuel bug type growth in the tanks.  This causes problems with blocked filters.
  • The chemical breakdown in the fuel to acids leads to engine equipment damage and leakage – mainly with the fuel hoses and seals.
  • Storage life of bio fuel is reduced – expected life is around six to twelve months in the fuel tank.
  • Cost of changing pipes and filters to accommodate bio fuel.
  • Cost of possible wastage, cleaning the tanks, and regular filter changes due to leakage and blockage.

Generally it is advisable for boat owners to only ask for non bio low sulphur fuel to encourage stockists to only supply this type of fuel.  As the supply chain is varied, the following advice should be considered going forward:-

  • Remove all water from the tank and filter/water traps.
  • Change fuel filters more frequently.
  • Turn the fuel around quicker.
  • Check for signs of fuel leaks during the season.
  • Fit a high quality fue/water separator and drain regularly.

The fuel system on older engines is much more likely to have issues as most modern leading engine manufacturers comply with the latest emission regulations and are designed to run on sulphur fuels.  If in doubt you could check for identification on the engine itself.

Are you exhausted at the end of the season?

Inspecting and maintaining your engine’s system is vital.
Here’s how to do it…………….
Starting at the engine end, it may not be absolutely clear which is the last part of the engine and the first part of the exhaust system. So the best thing is to start with the water injection elbow and pipe, usually rubber, bringing water from somewhere on the engine cylinder head.  This must be rated for hot water.  Car heater hose is quite suitable in this case.  Check for perishing and general condition, and look for leaks, particularly at both ends. The hose clamps should be of stainless steel, free from significant corrosion and gripping the pipe tightly, but not so tight that the pipe is reduced in diameter by more than a millimetre or two.  Over-tightening of hose clamps is a common mistake that leads to premature failure, as the edges will actually cut into the hose in extreme circumstances. Then work your way back along the exhaust system, looking for damage and deterioration to components and checking the tightness of the exhaust clamps.  Signs of blow-by due to loose joints are evident by staining of the pipe next to the hose.  But again, be wary of over-tightening tee-bolt type clamps. When inspecting an exhaust system you aren’t familiar with, do check that all the components are of the right quality, particularly the hose.  Replace anything that doesn’t come up to scratch. A common fault is lack of support, whcih can be dangerous and will certainly shorten the life of the system as stress is applied in places it shouldn’t be.  If you have any doubts about the quality, design or the way your system is assembled, your exhaust supplier will be happy to advise. Draining silencers always have some water in the bottom of them and should be supplied with a drain tap or plug.  Freezing can cause damage to the silencer as the water expands, so its wise to drain them off if the temperature is likely to fall to +5 deg C for fresh water and 0 deg C for salt.  This leaves a bit in hand for the weathermen to get it wrong! You should also drain all silencers before you lift the boat if there is any danger of the crane, lorry or ship putting the boat in a steep enough bow down angle to allow water to run forward out of the silencer.  Take particular care if the pipe entering the silencer is anywhere near the minimum one in eight gradient. Draining silencers for transport might seem unnecessary, but imagine what happens to the water in the silencers when the transporter has to make an emergency stop.  On ships, boats are often carried as deck cargo, strapped down laterally.  One good roll in rough weather and bingo – you may have a hydraulically locked engine and a very large bill.

Turning to winterisation… As the season slowly comes to a close and our thoughts turn to the winter months, not only is it time to think about winterising boats, it is also an ideal time to think about, research and carry out any additional work.  One of those things is looking at the engine noise…

Marine diesels create very high noise levels – often well over 100 decibels.  Engines are always located close to the boat user, generally in engine spaces made from GRP, timber or steel.  Engine noise is then amplifed by bouncing around between the hard bulkheads and the steel of the actual engines.  Noise contributes seriously to fatigue and seasickness, as well as spoiling life on board. There are several ways of reducing engine noise.  Adding weight and thickness to the bulkhead with insulation layers in one way to help reduce noise transmission.  Reducing the hardness and altering the texture of the bulkhead facing will absorb more noise and stop bouncing it around and possible even amplifying it. Just like double or triple glazing windows at home, it pays to constuct one’s noise barrier using multiple layers of thin material rather than one simple layer many times thicker. If you cocoon the engine with noise insulation you can reduce ariborne noise by 85% and transform the comfort for all on board.  Remember structure borne noise and exhaust noise are separate subjects. Insulation should be used on as much of the total surfaace of the engine room as possible.  Cut around pumps, filters and electrical items, but don’t leave large areas of hard surface for noise to bounce off.  Hatches and steps must fit neatly and should have a nice tight cushion such as hatch tape. Bulkheads around the engine should go right down to the hull.  Don’t leave openings where noise can leak forward – for instance under a cabin floor.  Remember that fuel and water tanks absorb in front of them, at least insulate the actual tank. The insulation panels can be stuck with conventional thixotropic adhesive such as Evostick or Dunlop Thix-o-fix.  The containers will have manufacturers instructions printed on them and these should be followed carefully including those related to health and safety and disposal of empty containers.

Understanding Your Bow Thruster…

Understanding Your Bow Thruster in the Inland Waterways Market

Tunnel systems provide a simple cost-effective solution and can be installed at two thirds their diameter below water level.  To achieve optimum performance and reduce the risk of damage from surface debris, an immersion depth of one complete tunnel diameter is advised.  The longer your tunnel, the less efficient your bow thruster will be.

The majority of tunnel thrusters come equipped with twin propellers, offering equal thrust in both directions.  Water cannot be compressed so the amount of thrust attainable is proportional to a thruster’s tunnel or turbine diameter.

Bow thruster systems consume more power than most other onboard functions and selecting the correct power source is essential.  There are three options, Electric Power,  where a dedicated bank of high cold cranking amperage (CCA) batteries will provide an ideal source of power for smaller bow thrusters.  These systems can be run for up to three minutes continuously without over heating.  Electric-hydraulic power, an electric DC power system allows you to combine the rugged reliability and lightweight hydraulic power head to the quick and easy installation of an electric motor.  Other advantages include the ability to select a dry and well ventilated area to install the electric motor and the possibility to centre heavy components such as batteries and motor and suitable midship section of the boat.  Pure Hydraulic Power bow thrusters benefit from unlimited run times.  If there is an exisiting hydraulic system on board our boat, or if you are considering installing one, this wil provide a highly cost-effective power option.

For more information on Bow Thrusters, please click here.

Boat Fuel Efficiency

If you haven’t done before, now is an ideal time to start thinking about your boat fuel efficiency.  Not only because of the current economic climate and rising fuel prices but also because it can go a small way into helping the environment too.

There are a few things that can be done to help increase your boats fuel efficiency ..

  • Monitor the Fuel Use – Increasingly we monitor fuel used by our cars.  This is also a good practice to follow for your boat, and hopefully you will notice how general ‘housekeeping’ can help with fuel efficiency.
  • The Right Engine – Purchase a low emission, fuel efficient engine.  Make sure that it is sufficient for your boat, so that you have enough power to handle the load.  Without the right engine, you will require more throttle to move the boat, which in turn will affect the fuel economy.
  • Using the Right Fuel – Make sure that you use the right fuel as recommended by the engine manufacturer and that you buy it from a reliable source.  Low quality fuel may foul the plugs, which in turn can cause the engine to stall or decrease in performance, both of which would burn more fuel.  If you have to mix your own fuel, follow the recommendations.  Too little or too much oil can harm your engine, affect overall performance and reduce fuel efficiency.  If possible change your engine from 2-stroke to 4-stroke as 30% of fuel and oil used ends up in the water.
  • A Clean Boat – Ensuring that the hull is free from any marine growth helps reduce drag in the water and allow easier handling.  Additionally, applying a coat of antifouling paint to the hull helps to reduce drag and friction on the hull.
  • Reducing Weight –Like all of us, a boat benefits from shedding some weight so give your boat a spring clean and get rid of any unnecessary items that are stored.  The lighter the boat, the less fuel it will burn.  Weight distribution is also an important factor, particularly for displacement boats.
  • Drain Unnecessary Water –At approximately eight pounds a gallon, excess water weight can really add up.  The lighter the boat is, the better fuel economy mileage you’ll get.  Ensure that bilges are kept dry and tops off water tanks only if necessary.
  • Reduce Speed – Simple & obvious solution really but slowing down and achieving a good average cruising speed will reduce fuel consumption.  However, it is important to remember that if you own planing vessels, these boats rely on the speed to plane along the surface water.  Without the speed, they will drag, and use up your fuel.
  • Checking Your Propeller – It is important to make sure you have the right size prop for your boat and that it is in good working order.  If your boat is over-propped, you will find it harder to get the boat up on the plane.  If, on the other hand. It is under-propped, whilst you will get your boat up on the plane, it will then be harder to maintain reasonable cruising speed.
  • Boat Handling –When you are satisfied that you are doing everything maintenance –wise for your boat, you could consider other ways to reduce boat fuel costs.  Examples being improving your skills of using the tides and wind to your advantage.  If managed correctly, this can help save you money long term.
  • Engine Maintenance – Like anything, your engine will benefit from regular servicing and maintenance, helping to eliminate any problems before they become too big.  Proper maintenance not only extends engine life, it also saves fuel.  Your local service point will be able to advice you on regular service requirements and also be able to help you with prop calculations.

The Sea Strainer Alarm System

Alarms instantly if the Sea Strainer blocks…..

Marine engines are cooled by raw sea water, drawn in through the bottom of the hull and pumped through the heat exchanger.  Block this vital supply and problems follow immediately.  The water pump impeller fails almost instantly and engine overheating follows.  In extreme situations really serious damage can be done.  Halyard’s new sea strainer alarm buys you precious seconds to deal with the problem before any damage occurs.  Impede the flow of water through the strainer, or start the engine with the seacocks turned off, and the sea strainer alarm tells you instantly.

The sea strainer alarm fits neatly into the water supply between the sea strainer and the engine raw water pump.  The unit is supplied complete with fittings for the appropriate hose diameter.  You simply cut the supply hose, fit the “T” piece into the hose and secure with hose clips.  You can then connect the sensor in the top of the “T” piece to the control box (up to 3 sensors can be connected, covering boats with single or twin engines and a generator).  The control box requires a 12v or 24v supply.  You can then connect the simple helm display to the control box.  If you prefer, you can fit the OEM control box, allowing you to incorporate your own dashboard lights instead of the standard helm display.  You can also connect an optional alarm siren, supplementing the simple buzzer supplied in the helm display.

The Theory Behind Common Rail Engines

The Nanni Diesel models, the T4.165, T4.180 & T4.200hp are based on common rail Toyota blocks from their rugged 4×4 automotive sector.

The common rail system uses high-pressurised fuel for improved fuel economy and provides robust engine power, while reducing noise and vibration.

The system stores fuel in the common rail, which has been pressurised and supplied by the supply pump.  By storing fuel at high pressure, the common rail can provide fuel at stable fuel injection pressure, regardless of boat speed or engine load.

The ECU (Electronic Control Unit) provides an electric current to the solenoid valve in the injector, which regulates the fuel injection timing and volume, and also monitors the internal fuel pressure of the common rail using the fuel pressure sensor.  The ECU regulates the supply pump to supply the fuel necessary to obtain the target fuel pressure.

In addition, this system uses two way valves (TWV) inside the injector to open and close the fuel injection.  Therefore, both timing and fuel injection volume can be precisely regulated by the ECU.  The common rail system gives two split fuel injections.  In order to soften combustion shock, this system performs ‘pilot injection’ as the subsidiary prior to the main fuel injection.  This helps to reduce marine engine vibration and noise.

Preparation For The New Season

After experiencing a very cold snap in winter, it will be necessary to pay extra attention to your boat, in particular the engine when preparing for the new season.

Firstly check the water level in the header tank.  It should be 3/4 inch from the top.  If it isn’t, replenish the tank with water (50% water and 50% anti-freeze) and check for leaks.  For a Nanni Diesel Coolant Chart, please click here.

Inspect the engine pipework and coolers.  If anything does not look right or has come apart then it may be worth seeking professional advice to prevent any further damage.

Check the oil for water before and after starting the engine.  If there is any present, flush the oil through and then investigate the source of the problem.

On starting the engine, if it is slow to crank over then check the battery.  This may have failed over the winter months and trying to start the engine with a flat battery will damage the starter.  This can be a very expensive item to replace.

When the engine is up and running, carry out a thorough inspection once again for water leaks.  Don’t forget to check that water is coming out of the exhaust and not into the bilge from a split exhaust pipe or silencer.  Check the fuel-water separator and drain off any water collected in the traps. It is advisable to do this again after a few hours cruising as the water that may have accumulated in the tank due to condensation over the winter will now find its way through to the water traps.  If there is a large amount of water in the traps it may be worth draining from the bottom of the fuel tank.

Domestic Water System.  After a severe period of cold weather like we have experienced recently, the Domestic Water System can also have problems. When the water tank is re-filled for the first time, and  the water pumps are turned on, the sight of water running out of cupboards and pipes leaking into the bilge is no fun.  The sign of a water tight system is when the water pump pressure switch clicks off and stays off.  However, if the pump cuts off and on, then a leak needs to be found.  Unfortunately, there is no easy way to do this apart form looking in all the cupboards and under the floors.  More often than not though, the part that has pushed apart will be at the bottom of the pipework where the water has laid and not been able to drain off.  Once the  system is water tight it is a good time to sterilise your water tank.  This can be done with sterilising tablets put into the tank and then flushed out, this will remove any unwanted bacteria.

Anti-freeze should be replaced every two years as the inhibitors start to degrade allowing corrosion to begin to attach itself to the internal parts of your engine.  Also mixing different types of anti-freeze is not a good idea as they can react together and form a jelly that will result in overheating.  This might not become apparent until the engine is put under load.

The above are some of the main points to think about after this particularly cold winter that we have been experiencing.  However,  at this time of the year, it is also time to start thinking about carrying out a complete preparation for the new season.

For Nanni Engine Spare Parts, please click here

Issues At Sea

Issues at Sea

Regular maintenance of engines and following service schedules are of paramount importance on any craft, wherever you sail.  When you head out to sea it’s even more important as a breakdown may well not just endanger your own life but risk the lives of your rescuers.

Planning the trip Voyage planning is basically common sense.  As a pleasure boat user, in particular, you should take into account the following points when planning a boat trip:-

  1. Weather – Check the weather forecast and get regular updates if you are planning to be out for any length of time.
  2. Tides – Check the tidal predictions for your trip and ensure that they fit with what you are planning to do.
  3. Vessel Limitations – Consider whether your boat is up to the proposed trip and that you have sufficient safety equipment and stores with you.
  4. Crew – Consider the experience and physical ability of your crew.
  5. Navigational Dangers – Familiarise yourself with any possible navigational dangers.
  6. Contingency Plan – Always have one in case anything should go wrong.
  7. Information Ashore – Ensure that someone ashore knows your plans and knows what to do should they become concerned.
  8. Spares – Keep essential spares on board – impeller, oil and fuel filters, fan belt and a few tools to change the items.

A twin engine boat generally has the luxury of being able to get back to shore but this is not always the case.  Obviously a craft with single engine failure can have serious consequences.


Engine Overheating Is water coming out of the exhaust?  If the answer is no, then,

  • Check intake filter and clean (turn the seacock off first).
  • Check the impeller.  If failed ensure all broken parts are found, possibly further along the pipe run and change.

If the answer is yes, then,

  • Check for belt tightness (If the alternator warning light is on, the belt may be slipping).  Adjust or change if necessary.
  • Check there is water in the heat exchanger  (or expansion tank) – by removing radiator cap when cooled (beware of pressure and potential scalding water) – top up with warm water if necessary ..
  • Check all intake/engines hose connections – tighten as necessary.

Other potential causes for overheating include:- faulty thermostat, clogged/scaled tube stack, cyclinder head gasket, cylinder head cracked.

Engine Loses Power or Cuts Out There are numerous reasons for this but it is commonly associated with a fuel issue, for example:-

  • Blocked fuel filter.  Change if necessary.
  • Contaminated fuel.  Clean tanks and treat with chemicals.  Change filters.
  • Dirty fuel.  May be necessary to change fuel filter 2-3 times.
  • Air getting sucked into fuel lines.  Re-tighten all joints and be aware air can be sucked in but not necessarily leak fuel.

Electrical Failure A failed battery and bad earth connections are the most common of electrical issues causing an engine not to start.  Ensure that the heavy main battery cables are secure on the batteries and battery switches and the negative (paint or corrosion at this point will cause a voltage drop).

A simple digital voltmeter is a very useful piece of equipment to keep on board.

In general terms – 12.7v – 12.8v is a fully charged battery (should show 14.4v with engine running fitted with standard alternator 14.7 with certain external controllers).   A battery reading below 12.2 will not normally start an engine.

Winter Maintenance

When thoughts turn to winter maintenance and servicing, correct preparation will ensure a successful boating season the following year.  Several different areas are involved:-

Hull Condition
If your boat is out of the water, it is an ideal to check and repair any hull damage, look out for scratches, blisters and abrasions to the hull.  Check transducers, and exterior surfaces of thru-hull fittings.  Ensure the engine sea strainer is clean, free of corrosion and secure.  Once hull maintenance is complete, touch-up or apply a new coat of anti-foul paint as needed.  Replace the anodes, which are inexpensive and prevent costly damage from corrosion and electrolysis.  Inspect the condition of the vessel’s shaft, cutlass bearing, supporting struts and propeller.  Check the swim platform and boarding ladder.

Vessel Interior
Inspect the condition of thru-hull fitting, ensure seacocks (valves) operate freely and check the flexible hoses and clips.  Consider proactive replacement of clips and hoses.  A failed thru-hull fitting can cause a major emergency.  Look for oil in the bilges.  If oil is present, identify it’s source, take appropriate action and fix the leak.  Clean the bilges to prevent oil spillage into the waterways and use oil absorbent pads in the engine spaces.  Check operation of bilge pumps and switches.  Lubricate stuffing boxes and rudder logs, and replace gland packing if required.  Your boat should be equipped with a good water separating filter that can reduce fuel problems.  Drain any water present in the filter and check the condition of all flexible fuel lines.

Fill the toilet bowl with water and check for leaks.  Check that the holding tank has pumped out and re-charge with chemical.  This would also be a good time to fit a deodoriser and holding tank charcoal filter.  Operate the Y-valve, ensuring its positions are clearly labelled and the handle is positioned correctly while in port.

Emergency Equipment
Spring is a good time to ensure your vessels safety equipment is in good order and that you comply with regulatory requirements.  Life jackets and floatation cushions left in boats during the winter can mildew so best stores at home.  Check the expiry dates on your visual distress flares.  Have your on-board fire extinguishers inspected.

Electrical Systems
It is a good idea to remove lead-acid batteries from your local boat in winter.  Ensure the battery is charged , its case is clean, clean or replace terminals if required and cables connections are tight, and that battery cables are in good condition.  Check the condition of the vessel bonding and electrical systems.  Defects here can cause corrosion and low voltage problems.  Ensure your navigation lights are operational.  Check the operation of on-board electronics.

Inboard Engines
Many of the tasks required to prepare your engine are routine and can be accomplished by individual boaters, although most marinas and boatyards can provided this service.  However, if your engine is in the latter stages of it’s life and requires major repair, this maybe an ideal opportunity to consider replacing it.  The cost of repair can sometimes exceed the cost of  a new engine, without the benefits of modern technology and fuel efficiencies.  Among the options to consider are replacing a petrol engine with a safer and more economical diesel engine, or even coming right up-to-date with a Hybrid Engine.  A Hybrid Engine incorporates an intercalated generator/drive motor with the diesel engine.  The advantages of which allow you to have periods of silent running and quickly re-charge a sizeable battery bank.  This is both environmentally friendly and economical to run.