Engines Part III: Why Diesel

Right up front as the title of this blogs states we went with a diesel engine.  As promised we thought that we would do our best to explain why we chose diesel over other available engine options.  We will mention that we are not engineers nor mechanics, however, our decisions were not made in a vacuum.  We had the help of many experts and did lots of research to come to the conclusions that we did.  Nonetheless we are going to try to explain our decision making process the best we can.

Although there are a few options out there that allow you to go fuel-less - like going solar or using wind technology - with trawlers the technology is not yet existent, especially for anything that can be defined as "sea worthy".  There are really only two types of fuel for trawlers - gas and diesel.


As we all know gasoline is a relatively cheap fuel that is available pretty much everywhere on the highway and this remains true at most marinas and fuel docks.  Gas marine motors are generally used for greater speed and a class of craft referred to as sport craft; however, some trawlers are equipped with gas engines.  Gas engines use spark plugs to ignite the fuel for combustion.  Gas engines are known to be quiet and efficient and in modern era are well engineered.


Diesel on the other hand is  slightly more limited on the road, but is growing. It is mandatory at pretty much any marina along the ocean, especially the inter-coastal water way. Diesel as a fuel burns for a longer period of time than gas and uses compression to produce combustion, thus no need for spark plugs.  Diesel engines are known to generate high amounts of torque and are known for their efficiency.  Diesel engines are typically louder than gas engines.


Gas V Diesel:

As just discussed the use of either fuel is perfectly acceptable out on the water.   Gas and diesel are equally available at marinas and are perfectly acceptable out on the water. The question that came up in our mind was, "Okay, so what's the difference?"

The size of the vessel matters when discussing the type of engine. Gas as described above is known for its performance and sport craft, while diesel is known for larger trawler and work vessels.  A vessel 40ft or smaller may do fine with a gas engine but the owner really has to look at the overall gallon per hour ratio and weight of the vessel.  While larger and heavier boats lose performance while using the gas combustion engines. 

Although performance is a good reason to make decisions, as we have discussed in other posts, we have found the most important reason to make decisions is efficiency and cost.  

The first thing when deciding an engine is cost.  In this there are two different types of cost: their is the "original" cost of the engine and then their is the "long term" cost of the engine. However, beyond these two types of costs, we also need to understand the efficiency over the "long haul."  When it comes to this point the experts over at powerproductsystems.com had to say:

"(A) major different between a marine gas engine and a marine diesel engine is the cost. Marine diesel engines cost much more upfront than marine gas engines. A boat with a diesel engine can add tens of thousands of dollars to the purchase price of your boat. However, a boat with a marine diesel engine will have a longer engine life and retain its value."

This is a common theme around most of experts... we did our research by speaking to several experts, which included the builder of Endeavour Trawler Cats, read magazines, and conducted internet research and we came to the same conclusion.

After looking at several engines and analyzing the different types of fuel we made the decision to use the Cummins Turbo Diesel.

If you have questions about our decisions please post onto comments or send us an email.  We hope you will check out our other adventure blog, and charter with us soon.

Engines Part I: What does every boat need? More Power...well maybe

So let's start this blog with one of the most important items on a boat: the engine. When discussing trawler engines, just like with car engines,  the most important factors are type of fuel, efficiency, gallons per hour, and horsepower. In the next several posts we will discuss all of these items and their importance in choosing the best product for your vessel.

The Grampstr's Pride has two Tier 3 Cummins QSB 6.7ltr Turbo marine Diesel engines. In future posts we will discuss the reasons for the Cummins engines, but for today we will focus purely on power.

The Diesel Cummings engines we selected have that original 380 HP and can be boosted to 425HP.

So while on trial with some Cummins Experts on the boat they recommended that we increase from the original factory settings to 380HP which allowed a max output of 1335 LBS of Torque at 2000 RPM.  At this horsepower the props would spin at approximately 2890RPM.  According to the boat experts this was not enough and it should have ran 3000 RPM.  So at the 380HP the boat would not perform to the level of its highest efficiency.  

By raising the horse power to 425HP we were able to get our torque to 1424lbs at 2000 RPM.  This amount of horse power allowed the propeller to spin at the perfect RPM of 3000 RPM at max speed the engine to perform at an optimal performance.

So once we raised to 425 HP we asked the obvious question:

"Should we give it more power?'

The answer was simple: No! The reason being is that it will not at all help with engine performance. In fact, we were told it would actually make the vessel less efficient.  According to the experts, any more horsepower would not result in any more RPM output for the props, which means any extra HP at that point is just overkill and a true waste of fuel.  So we just needed a little more power!

If you would like to learn more or have questions please post your questions or comments in the section below.  We would also love for you to contact us about Chartering the Grampstr's Pride.