Repower : The Nido Del Mar Story
Written by Mark Capitano
Ever wonder what it takes to put new engines in boat. We did and let me tell you its
a giant project. This is the story of re-powering our 48 foot Offshore Yachtfisher, Nido
The Need for Speed:
It all started with the need for speed. When we originally purchased our (used) boat it
came with twin 200 HP Perkins Diesels. The boat had a cruise speed of 9kts. At first this
was fine especially considering that we had just sold a sailboat that cruised at four kts.
Then we started fishing. Speed soon became an issue, as we needed to do multiple day trips
to get where the fish were. Just the ride to a spot 50 miles away took 6 hours and that
didnt include fishing. We started our search for speed with talk of a new boat and
began looking around. We were hoping to find something that did 15 kts or better. It soon
became apparent that we couldnt replace what we had and get the speed we wanted
without spending a lot more money then we had in the bank. That meant that we would first
have to sell our boat and still put in a lot of cash. That was when we began to think of
For us the math made sense. First we knew we got a great buy on our boat. To replace our
boat with other USED boats of the same type but with larger engines would cost almost
double what we had paid. A few phone calls quickly told us that there was no way we would
spend that much money on a re-power.
Deciding what engines
First we went to our regular mechanic. We told him we wanted to go at least 15 kts and
asked what he thought would be best. He suggested Yanmar diesels, as he was a Yanmar
dealer. Not wanting to be stuck with just one choice we also called CAT, Detroit and
The bid process was very technical and time consuming. Engine dealers and their reps
coming to the boat and measuring, checking shaft sizes, worrying about exhaust pressure.
Everyone telling us their engine was best and their people were experts. We spent days and
even weeks on the phone collecting and then comparing information. After hearing all the
testimony and very careful consideration we decided that Cummins was best suited to our
needs. The Cummins 370HP B Diamond series diesels to be precise.
Finding the right guy to install our new engines
The next step was deciding who would put them in. We talked and listened to many mechanics
and we checked with our local boat yard. It turned out that there finding the right guy
was more difficult then we had anticipated. There are not many guys around with the
expertise and willingness to tackle a project of our size.
We eventually settled on a Repower Specialist who did all the work except
props in house. There are not many of these guys around. The alternative is a mechanic who
subs out all or most of the fabrication work to other shops. We liked the idea of most of
the work being done under the same roof by the same guy. In addition to coming across as
very knowledgeable he was highly recommended by both Cummins and the transmission
manufactures. On the downside this mechanic was located 100 miles away but based on the
recommendations and what we had seen we felt he was worth the trip. (Please see the
link at the bottom of the page).
Of course price was also very important. Trying to compare all bids is not easy. Different
engines require different systems and cost can vary greatly. For instance some engines,
though less expensive then their counterparts, required a larger exhaust system then we
had in place. That meant additional cost in other areas. You usually dont find this
out until a mechanic has been aboard and seen and measured your existing system.
The mechanic we had selected was not the least expensive, but also not the most money. In
addition this mechanic was the only one that gave a FIRM price. That is, if it were more
to do the work outlined in the original bid he said he would not charge more. That
Of course every boat is different and no two will cost the same to repower. Still I
thought someone may be interested in what we spent. It was $85,000.00 for everything. As
you can see this is not something to be taken lightly however in our case we figure we
saved about $100,000 when compared to replacing our boat with another used vessel. Below
is a list of everything we had done.
Its not just a Repower
There are lots of other items that must be considered when replacing engines aboard a
boat. This is especially true when going way up in horsepower as we did. We were removing
twin 200 HP engines and replacing them with 370 HP engines. That meant a lot of systems
needed to be made larger or stronger. Fortunately our boats basic structure could handle
larger motors so no major structural reinforcing work was required. Even so a lot of
changes were needed.
Here is what we had done and what was included in our price.
1. Old engine removal.
2. Two New Cummins 370hp B Diamond Series Engines.
3. Two New ZF transmissions.
4. New engine mounts. 5. New stronger propeller shafts (same diameter / better material).
6. New larger Nibral props.
7. New dripless shaft packing systems.
8. Side venting of exhausts and punching out the mufflers to relieve exhaust pressure.
9. We had the entire engine room painted and refurbished while the engines were out.
10. We completely replaced the fuel system with new larger lines and a new
fuel/water-separating filter system.
11. We had to put in larger raw water intakes.
12. We had to put in larger raw water strainers and all new hoses.
13. New sets of engine gauges for both the upper and lower stations.
14. New bottom paint
15. New raw water through hull and seacock for a future bait tank. (figured we mind as
well while the boat was out of the water)
16. 2 months of Boat Yard storage including removing and replacing boat in water.
17. Replacement of the 12-Volt system from the battery boxes up to the electrical panel.
18. A new custom battery box.
The actual installation is the fun part. Virtually everything that attaches the engines to
the boat is CUSTOM MADE . Our boat was an especially tough installation. Our engines are
located inside the salon, under the floor. The access hatches are in the middle of the
salon. That meant that the engines needed to be brought inside the boat. They were then
lowered into the center of the engine room and moved outward, back under the salon floor,
onto the stringers. Each engine took a full day just to get them into place. Because our
boat was so far away we could not get there except on weekends.
We called our mechanic everyday for an update and just to talk about the work and boat.
Our mechanic was as patient and helpful. This is important with a job where you are
spending so much money. The last thing you need is a mechanic thats doesnt
want to take the time to talk to his customer. Frankly we bugged the hell out of our guy
and he never once complained or made us feel like he was too busy. He always had time to
talk to us about the job. He even spent two full Sundays (his only day off) with us to
discuss the work and see other projects he had completed.
Re-powers take a long time
At this point I need to mention how much time had passed since we started the project. By
the time we had selected the engines and the mechanic four months had passed. That was
before the actual installation even began. Very few things go fast when looking into a
re-power. Days on the phone getting rough numbers. Everyone needs to get back to
you. Mechanics are backed up and cant get to your boat for 2 weeks to do a
bid, then its two more weeks to get all the numbers together. Then you decide you need to
look at another engine manufacture and the whole process starts over.
Once we got the boat into the boat yard the installation took another 2 months. That put
the total job from start to finish at half a year. The bottom line is be prepared to be
working on repower for 6 months. If its less then that be happy.
The Results of the Project
We were very lucky. For us very few things went wrong. There were very few surprises. The
big question was would we get the 15 kts we were hoping for?
Sure the computer models said we would, but what would really happen in the ocean. When we
hit the Throttles would we fall back in our seats or wish we had bought another boat? The
one thing our mechanic, or for that matter any mechanic, couldnt tell us was how
fast we would REALLY go. They all told us every boat was different and we would have to
wait and see what the final outcome would be.
The day finally came for the Sea Trial. We had waited a very long time for this day and it
was a long ride to the boat yard. We were anticipating the worst as the day before our
mechanic had taken the boat out for a pre sea trial. I had spoken with him
after his return to port. In a very somber tone he had refused to tell me how fast our
boat was, just to wait and see when we got there.
We arrived at the dock and climbed aboard. After a few adjustments we were off. We drove
the boat slowly out of the harbor. You could feel the power of the new engines even at
idle. The sounds, vibrations, feel of the throttles, everything was different. As we left
the breakwater we slowly pushed the throttles forward. The Rpms came up and you
could hear the Turbos kick in. Suddenly the bow of the boat rose and immediately
climbed onto plain. As we brought her up to 2800 cruise RPM we hit 18 kts. YES! Boy we
were happy! Then we pushed the throttles to full speed and the boat broke 21kts. We were
shocked! We had never expected our 20+ ton 48 footer to go that fast. Happy as clams we
put the boat through her paces without any problems. After dropping off our mechanic we
returned to our home dock with grins from ear to ear. For us everything had worked out
PS For the record our mechanic was Tony Athens of Seaboard Marine in Oxnard. Thanks to
Tony's great work we have what I consider a New Boat. Tony also has a
website. I can recommend his work and customer support highly.
SEABOARD MARINE / TONY ATHENS
2947 W. 5th. St.
Oxnard, California 93030
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