Engines part V: Lessons Learned - The Trial

This will be the last blog on engines for a while.  We know that we have inundated you with engine information, but hope the information is helpful to you.  If you have any questions please feel free to contact us or write questions in the comments.  We will either answer your question in a separate blog or right on the thread.

As a recap, we have discussed several aspects of engines:  fuel efficiency, fuel type, engine type, and calculations.  But one thing we discovered during engine trials are the lessons that we learned.

One of the most fun and truly challenging parts of building the Grampstr's Pride was the Trial phase.  What made this fun was that we had some really cool experts on our boat to show us how to run the equipment and do some fine tuning.  During this process we had the opportunity to watch the experts at Endeavour, Cummins, and Twin Disk make the Grampstr's Pride ready and sea-worthy.  While working on the vessel we learned a few things that affect the engine - what, you ask? Efficiency!

This is where we learned about the sweet spots for running the motor, prop size and pitch, and most importantly how much horse power was too much.  This is what made these trials so fascinating to us as owners and captains. The experts worked out kinks: such as propeller pitch, transmission controls, and jet thruster conversions.  In the end the issues were totally worth it and we are so excited to have had everyone on the Trawler at once. 

Although this is the last blog on the engine series, you can look forward to future blog posts when we will talk about all of the great technology on the Trawler.


Engines IV: Yanmar V Cummins Marine Engines

As some of you may have realized we used to own the Grampstr's Endeavour a 38ft TrawlerCat, which was a beautiful trawler and in the future we will discuss our transition to the Grampstr's Pride, a 48ft TrawlerCat, but for now we are going to discuss one big difference -the engines. 


The Grampstr's Endeavour had two Yanmar Diesel engines.  Whereas, the Grampstr's Pride  has two tier 3 Cummins QSB 6.7ltr Turbo marine Diesel engines.  So the question you may be wondering is why the change in engines?

Lets first discuss the reasons why we did not go with another type of engine. It was not because there were issues with the Yanmar Diesel engines.  Yanmar has a great Marine reputation and has an excellent product.  It was also not because they did not have an engine that would propel the larger boat.  Yanmar has an excellent series of engines for most size watercraft.

The reason we went with the Cummins engines over the Yanmar was fuel efficiency.  After lots of research it turned out that Cummins Tier 3 engine was going to deliver a lot more efficiency and power for the size and type of trawler we were building.  After lots of discussion with Endeavour it was decided that this would be a good way to go.

As we have discussed there are a lot of things that go into choosing an engine.  If you have any questions on why we choose the engine we did please reach out to us.

We hope you will charter with us soon!

Engines Part II: The Need For Speed?

Briefly, in the last post we discussed the basic concept of efficiency, particularly that efficiency in trawlers is measured in Gal/Hour.  When it comes to boating in general the efficiency of a vessel is measured in Gal/hour, or as stated Gallons per hour.  The reason for this is that distance and speed is not an effective measure of engine performance.  The pros over at boatingmag.com have this to say:

"You measure fuel efficiency in pounds of fuel used per horsepower developed per hour. The pros call it 'brake-specific fuel consumption.' This makes it important to know that gasoline weighs about 6.1 pounds per gallon and diesel fuel 7.2 pounds per gallon."

As indicated by the equation for gal/per hour this calculation allows you to determine fuel burn for both stopping and while in idol.  This model also allows you to measure your efficiency at different speeds/rpm.  We are very happy with our diesel Cummins engines.

The Grampstr's Pride operates at5.9 Gal/Hour at 8 Knots/Hour (approx. 10 MPH), which is our recommended cruising speed. While at full speed of 19 Knots/Hour (22 MPH) the vessel operates at 38 Gal/Hour.

However, we should mention that there are two cruise "sweet spots." The first at 1350 RPM 8Knots (10 MPH), which expends as described above 5.9 Gal/Hr. The second at 2200 RPM when the vessel will travel 15 Knots(17MPH) for 19 Gal/Hour.

Based on this information it is easily determined that although it is fun to go fast the cost of fuel may outweigh the need for speed! But the moral of the story is also to FIND THE SWEET SPOT!

We hope you will contact us soon and consider chartering.


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.