Gas to Diesel Conversion of a 33 Egg Harbor

Overview/Lessons Learned

Why repower, and why to a completely different source of power?

We knew the time was drawing near, our 16-year old gas engines (454's) served us well, but they were getting tired and somewhat problematic. The thought of cruising long distances were always curtailed with, that might be too much to ask from the old engines. So we discussed the viability of a newer boat or repower ours. We really liked our boat, it fit the type of cruising we like to do and plenty of room even for two growing boys.

The decision was made, repower ours. Now what do we want to repower with? What could we afford? These were some pretty basic questions, but they were critical to the final outcome.

We knew we needed better fuel economy and certainly some increase in cruising speed would be welcome. One thing that has changed in recent years is that marine technology has greatly advanced in almost all areas of propulsion then what was available 16 years ago. Should we go with the advanced fuel injection gas power plants or possibly the many new models of modern lightweight diesels?

Starting out with a repowering project could seem undaunting. Should we go gas or diesel, what manufacturer, what model, what boat yard, these questions all jump out at you all at once. The first thing you need to do is give yourself enough time, learn all the aspects that need to be accounted for within a project of this size, then proceed with listing all the key components keeping in mind what you truly hope to accomplish. Do not assume the first boat yard you approach has the best idea on how the project should be done.

One great resource that was not available 10 years ago is the Internet. With this tool at your disposal you have access to millions of fellow boaters, mechanics, boat yards and manufacturer all just a click away. I was able to correspond with people from New York to Australia. Posting questions to a global audience within public meeting places called forums can yield some very interesting viewpoints, such as, product reliability, warranty support and overall general performance.

This is not to say the whole project can be done from the comforts of your easy chair. To really pull this off you'll need to do some legwork. Visit boat yards, speak to mechanics, call owners of your particular boat that have already done the project and get a feel for what you need to account for and what to watch for.

At this point you'll have a good understanding of what to expect and the work that's entailed. Now you are prepared to get estimates from boat yards that would possibly perform the work. Make sure all aspects of the project are broken down on the work order with clear break down of the costs. Keep in mind, total cost is not the driving factor, but a budgetary line needs to be drawn.

The ultimate decision will come from the dealer or boat yard that you have the most comfortable feeling. Whose description of the process closely matches your ideals, but never exclude knowledgeable insight from experienced boat yards, sometimes their knowledge exceeds local folklore.

When your repower project is underway, be part of it. Very few boat yards would bar you from all the action. This also enables you to see first hand all the labor necessary to perform the task and would allow quicker response time when decisions need to be made when encountering something unexpected.

For us the final decision was Al Grover's in Freeport, New York. Dante Grover who runs the yard has a very good reputation for performing this type of work and his price came right in with most other estimates. What really attracted us to Al Grover's was a comfort factor. You never felt as if they were doing you a favor, they explained every aspect and would also listen to your suggestions. Dante Grover and his staff achieved everything we wanted from the installation. The project was brought in exactly as quoted, delivered precisely on time and of course, performed better than expected, which is quite an accomplishment in any business!

Sea Trial

I had some pretty high hopes as to what the boat would do, so I was extremely happy to have those numbers come true along with some extra.

Saturday couldn't come to soon, sunny light breeze, perfect for trials. Fired up the 300 hpYanmars and they instantly came to life although a bit smoky, I was told they poured in a gallon of oil per tank for break in and it would diminish when they warmed up, which it did.

Gas		Diesel
RPM	MPH	RPM	MPH
3000	22	2500	19.5
3200	24	3000	26
3500	27.5	3200	28
4000	31	3500	30
.	.	3800	32.5
Fuel Consumption	32-34 GPH cruise	Fuel Consumption	15 GPH Cruise

From the words of my 10 year old son Daniel, "Totally Awesome!"

First impressions, extremely quiet and smooth, the exhaust was equal to if not quieter then the gas 454's. The next surprise came when Dante Grover throttled up using no trim tab and the boat literally jumped on to plane. Again extremely smooth and quiet.

Now for the numbers, at 2600 rpm's it was planing along real well, brought the throttle up to 3300 and the boat took off, cruising at 24.5 knots, throttled up to 3500 and it was in the high end of 25 knots. Full throttle met spec at 3800 and was 27-28 knots (33 mph). Factory spec call from continuous duty at 3600 rpm's, so it's nice to be able to run way below even that number. Fuel consumption based on factory tests and similar boat tests with same setup is 15 gph at 3600 rpm.

With the large 22" x 26" four bladed Nibral wheels the boat immediately jumps in gear. Stopping and turning instantly, the relatively fast speed at idle will take some getting use to.