Keep the Diesel?

10/19/12

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Why Not Keep the Diesel?

With the invention of the combustion engine we have shown that we can go against even the strongest wind and current and go where we want, when we want. The price we pay is just another example of how we enslave ourselves willingly.  To have a diesel engine requires: 

  • Considerable additional expense, weight and complexity added to the vessel,

  •  Maintenance on a regular basis to keep it from falling apart,

  •  A willingness to listen to a noisy, vibrating engine when it is used,

  • Diesel fuel that requires care since it can easily be contaminated by water or algae.  (This means keeping the tanks full to minimize condensation and adding treatments to the fuel.)

Let’s address the positives and negatives of diesels.  It is true that they do produce more horsepower per gallon than other engines.  But to manage all the power generated by the fuel the engines have to be strong and heavy.  In fact, they are almost twice the weight for the same horse power compared to your typical outboard.   This does not matter in heavy cruiser, but in a catamaran where speed is dependant on weight, it is a critical factor.   Now diesels are best suited for running continuously at a single speed.  They are poor at managing the varied speeds and short run time for docking or for leaving and entering the marina.  In fact, it is estimated that 90% of the usable run time of a typical marine diesel is used running it to warm up or as preventative maintenance to keep it functional.  Now this completely destroys any arguments about efficiency, and certainly even the true blue water cruiser spends little time motoring due to the lack of fuel offshore.  He generally only uses it for charging the batteries once a day for an hour at most (if even that much) and for the typical leaving/entering the port or anchorage. 

Another argument I often here is that often use in favor of diesel is that it is less combustible than gasoline.  This is true, but considering over 90% of the boats sold in the US use Gasoline (and are under 20 feet in length) it is hardly a compelling argument.  Also you must consider, I already have to have gasoline aboard for the dingy outboard and Honda generator. So having a third fuel, diesel, which is “safer” in addition to propane and gas, adds little safety in my mind. What is critical is that all fuel is planned for and properly store aboard.  A big advantage on a cat is that the lockers on either side of the engine compartment are vented to the sea out the bottom making them perfect for storing gas and propane.  Also the engine compartment could be easily vented in the same manner making it a perfect location for gas fuel tanks next to the outboard once the engine is removed.

Now lets look at the Westerbeke 30B which is truly a wonderful engine and highly dependable in more detail.  The engine consists of a well filtered fuel system to protect the water sensitive injectors as well as glow plugs to preheat the cylinders so it starts easily.  It has a fresh water cooling system to reduce the corrosion impact of saltwater on it and a separate seawater system that only combine in the heat exchanger.  Then on the back of it has a transmission allowing it to easily shift from forward to backwards using a single level throttle shift control that itself is a wonder internally.   Also, add to this starter, alternator, fuel pump and a kill cable to stop the fuel that is run to the helm (which is prone to stay in the shutoff position; so please remember to push it back down after stopping the engine; maybe you should put a sign there?) Also it has a display panel with start and glow plug warm buttons as well as amp, rpm and hour usage displays.   There is a steel oil pressure sensor rusting away up front and a wonderful green tinged copper heat exchanger on top.  The engine is composed of a variety of metals that each separately is well suited for their purpose no doubt.  The bolts are all fortunately steel so that a magnetic pickup can easily retrieve them when dropped under the engine where they surely will end up should you dare to remove one.  Did I mention that it also connects to a forced air heater via the water hoses which uses the engine excess heat to warm the cabin.

I have had good luck with the engine overall, I think; “it always got me home” is my basis for this conclusion. In the 6 years that I have owned the diesel, I have had to replace the raw water pump for around $300 in parts and more than 8 hours time working on it and even had to buy special tools to get it on and off.  Then the glow plug relay went bad, cost me a week trouble shooting and when I could not get the replacement to work, it cost me another $1000 for a knowledgeable mechanic to figure it out (he almost gave up too.)  Took him almost half a days time not including commuting time which I also had to pay for (he did change the oil while he was there so it was not a total waste.)  The impellers seem to only last a year no matter how few hours the engine is run.   This is a 30 minutes exercise on your knees if you are good at it (don’t worry you will get better at it each year.)  Oh, and the $10 zincs in the heat exchanger love to be changed if you ever have a moment with nothing else to do or to fix on the boat.

My point is "how many things are there to go wrong over time?"  I think, too many, to be sure.  Also the variety of metals used in it are going to result in corrosion of the galvanic variety the will eat up the engine eventually regardless of how it is used.  I have been able to slow the corrosion issue down with the wonderful Counter-Act already described in another section.  But still it only slows down the corrosion by an estimated 90%; nothing can stop it completely.

Now let’s consider when it is running; it is noisy and vibrates everything on the boat loose.  When you think about it; it is everything that sailing is supposed to take me away from and listening to it is close to having my teeth cleaned on the pain scale (if I had to compare it to something else that I dislike.)

Sorry if I sound a bit anti diesel. I am not anti diesel overall. After all my father was a truck driver for the last 35 years before he retired, so I do appreciate the advantages of a diesel.  I think diesels are impressive engines as engines go, but they are not a good fit for small sailboats for the reasons I have already explained above.  

Also, I am a sailor, and generally I think sailors have little love for engines when we are out sailing although we all recognize them as a necessary evil. So please don’t expect a glowing review from me.  Basically, the more I deal with it the less I want to deal with it….life is already complicated enough…..and let’s face it, it is not a necessity by any means. Please bring on the E-Pods with the great hope of a simpler life.....

 

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