Fix it or flick it

Practical: Engines

Should you fix it or flick it? Matt Cummings debates the question that has given many a cruiser a headache when an engine past the first flush of youth decides to take an unscheduled break.

So you're cruising along with a full main, headsail sheeted home and it's a beautiful day with a perfect breeze that's allowing you to steer a compass course that will make your next waypoint. Right then you're thinking to yourself that "it can't get any better than this", and you're probably right.

An hour later the breeze shifts 20deg to the wrong side of the equation and the whole scenario changes, which means it's time to fire up the donk, get rid of the headsail and motorsail on the course that will get you to your destination.

The first mate's in the galley making a cuppa, so you ask your offsider to turn the key, push the button and start Old Faithful. As usual she fires into life and provides that familiar feeling of security that having a good reliable motor has given you for many years. Shortly afterwards something along the lines of "the motor is making some strange noises down here" gets relayed to the cockpit. The next sounds you hear are "budda bang budda boom" and your ever-reliable trusty friend comes to a grinding halt.

The unforeseen
Sometimes just as with any other machine, things which cannot be foreseen happen within the engine. Once you have got the boat safely tied up and have had a chance to relax and think about what has taken place you will probably come to the conclusion that you will need to call in the doctor (marine mechanic).

One of the first things he will probably do is try to turn the engine over by hand to establish whether or not the engine is seized. More often than not if the engine has had a severe overheat, the rings have seized in the bore and snapped a connecting rod or have caused damage that is just as grave as that.

The end result will mean the engine will have to come out of the boat and the decision made on whether to rebuild or re-power with a new modern electronic engine.

Improving reliability
Once the old engine is out of the boat there are many things you can do to improve the reliability, look and value of your vessel. Firstly if the engine has been in the boat for its whole life then no doubt the area under and around it will need a good tidy-up because no matter how much of a contortionist you are you'll never be able to get into every nook and cranny while the motor is in place. Depending on what the engine compartment space is lined with it's worth really getting into it, eg if it's glass, clean it down, give it a light sand and them flowcoat the area with a bright colour so once the engine is in place, locating leaks or identifying belt wear won't be a worry and it also makes it look a million bucks.

Because most of the older engines are by nature noisier than the modern version it could be a good time also to sound-deaden the area. You can buy insulation from most good chandlers: it comes in sheets, is easy to cut and can be mounted with contact adhesive, metallised tape and few screws or clouts. Make sure you do a good job of fixing it, as the last thing you want is it falling on the alternator belt. I have seen this happen, and it makes a real mess and if you're unlucky it gets between the pulley and the belt and rips the belt off.

Bilge pumps
One thing I'm really into is bilge pumps. I have seen so many good boats go down because of bilge pump or float switch failure. A large number of boats have their bilge pumps located in the engine compartment under the engine sump, so it is a great chance to check the wiring and maybe replace the float switch and pump.. If you are going to replace the pump, put in a bigger one: bigger is better when it comes to bilge pumps.

Rebuilding
"How much is this going to cost me?" I hear you say! Well, let's look at the rebuild first.

The first question to ask is: how old is the old engine? If it's heading towards the 20-year mark then even talking about a rebuild is probably not a good idea. In some cases when older engines have been rebuilt after a good wad of cash, they let go somewhere else a year later and you're back to square one, albeit a lot poorer. If the engine is maybe 10 to 15 years old and needs only the head redone rather than a major overall, in most cases that will give you another 5 to 10 years of good service and would be worth spending some money on.

What's involved
The fact that all the same parts are going back into the vessel means there will be no real need to change much of the existing setup, which makes the mechanic's job a little easier and less time-consuming. There will be no change from around $7000 on this job. If I were in that situation I would also get a bigger alternator because most of the older engines had small alternators, and have the starter motor rebuilt or replaced, because they would be the next weakest links in an old motor.

Downside
The downside to all of this is that after you have spent the $7000 you probably won't have a warranty because with a very old motor most mechanics are unlikely to take on the liability. If the job's done well and the rest of the parts are in good shape, there is every chance the thing will run for years, but there is also a chance it could crap out on you again but a decision to rebuild comes down to your funds available at the time.

Beyond fixing
If you get to the stage where you have pulled down the motor and find there is damage to things like the crankshaft, pistons, rings etc and the engine is 20 years old, your mechanic will probably want to sit you down for a chat. If you're going to be doing big miles and heading to remote locations, as we all would like to do, the last thing you need is engine trouble. If your boat is in good nick and has many years of cruising left, spending a wad of cash on a new donk is the only way to travel.

Now planning to put in a new motor is more easily said than done. You'll want to have a detailed quote explaining exactly what you will be getting for your money. It is very easy for these operations to overrun the budget if you don't really look at every possible angle of supply and installation. A big plus with modern diesel engines is that they are lighter, more fuel-efficient, quieter and more powerful and probably have a larger alternator output than your old clunker. All this boils down to being able to move through the water faster and more quietly and cheaply under motor. The increased alternator output will also enable you to charge your batteries more efficiently, which means you will save money and be a little friendlier to the environment.

Battery setup
While deciding on the motor brand you may as well look at the battery setup and the size, age and management of the charging system. Even if you have had no problems with your battery system, adding a VSR (voltage sensitive relay) would be a really good idea. The relay controls the battery charging voltage so both house and engine battery banks are maintained at their optimum levels. If you have had troubles like not having enough battery power to get through the day without running the motor or hooking up a 240-volt charger, then it's time to look at how much power you are really using and provide the necessary battery capacity to suit. If you are going to install AGM or gel batteries, make sure the charging system meets the specification of the battery manufacturer or you're wasting your money.

Hot water
With the new modern engines comes the opportunity to have hot water from your diesel engine, which is a bit of a luxury but by giving the lady of the yacht a chance to have a little hot water to wash her hair has to win a few points. All these things should be thought of prior to choosing a new motor. If you do a bulk order you will save a fair chunk of money.

When your mechanic looks at the engine refit for the first time he will take into account a whole range of things. How big is the new engine - height, width and length? Will the engine bearers need to be modified to accommodate the new engine mounts? Sometimes you'll need a shipwright if the mechanics is not up to it! Will the exhaust need to be re-run? If you're lucky you can even do the engine changeover without even slipping the boat. This will depend on the shaft length and diameter, which if long enough and the right diameter, will allow the shaft to be cut and the new coupling attached without changing the whole shaft, bearing, prop etc.

Couplings
Mechanics can source a coupling that comes in two parts, which makes the installation easy. In some cases the gearbox ratio and the size of the prop can be worked out in advance and if you know the type and size of the running gear it really helps when the time for a refit comes. If you can avoid lifting the boat out of the water, you'll save a good few dollars.

Some rough costings in the replacement of a 55hp diesel would be as follows. New motor: $17k to 20k, which would include engine mounts, wiring loom, gauges and gearbox. For a fairly straightforward installation you could look at somewhere around $5k to $6k, which would allow for the crane or device for lifting out the old and lifting in the new motor. You could always get it done a lot more cheaply if you know the right people but in general this is a good guide.

Peace of mind
My own choice would be the new motor because then you can be pretty sure you'll enjoy the peace of mind that comes with having a new donk. I also believe that out of the bad luck of engine failure comes a great opportunity to make your pride and joy cleaner, safer and more reliable - both mechanically and electrically - which in turn will add dollars to the resale value of your investment.