[RicM]

Did something like this conversation occur over on BoatDiesel.com a while ago? In any case, if that’s the boat you want, and those are the engines you want, go for it. Life is too short to own an ugly boat, or is it Life is too ugly to own a short boat? Something like that, in any case, keep us informed about your quest. I for one would very much like to hear more about this project. Believe me, I spent many hours pondering the same questions before I decided to learn to love my 6-71’s. Best of luck!

[RicM]

I have a 1993 Jersey Dawn III with fresh 6-71’s. It’s a great boat but with 1/2 to 2/3 load of fuel & water it weighs close to 38,000 lbs ( that’s from a travel lift scale). I did extensive research on a repower, including some consulting from this website, and I have to agree with Rob, a 40′ Ocean is what you are specifying here, so why not just buy one? Putting Cummins power in a Jersey will run you close to $150K, a little less if you do rebuilts, and you will never get that money back. The base boat will be $80-90K, so that puts you at close to $250K for a 30 year old boat by the time you put new electronics in it and redesign the helm station for the electronic controls. Are you going to leave those old fuel tanks in place? My 42 only has a 20 Gallon black water tank, are you going to want to replace that? Good luck, it’s built into the stringers.

My boat has pretty hard chines, which makes it nice and stable, but I bet it would pound like hell in head sea at 25 knots plus. Once you get going that fast you really need a fine entry in anything but pond flat water. The Jersey hull was not really built for that kind of speed, so yeah, it’s possible but how often would you actually be able to do it?

There’s plenty of newer, lighter boats with the specs you are looking for in the $250K price range and you don’t have to go through the pain of ripping a boat apart and putting it back together. Your choice, but it seems like the long way around to me.

[RicM]

Thanks Bill. As always this project is driven by the budget to a degree. I am thinking about remanned QSB’s

[RicM]

Well first of all I don’t see a way to correct the misspelling in the first title? I see the Spell Check doesn’t recognize the word, and changes it to “Reposer”. Unfortunate!

Anyway, in the first scenario, and as we have done it in the past, we will be running the boat up and down the ICW, both inside and off shore when weather permits. The off shore runs tend to be 100-120 NM dashes when the weather permits, 18-20 knots for 6-7 hours. The boat is a planing hull, hard chines, and weighs about 38,000 lbs. The 6-71’s push it about 17-18 knots at 1900 RPM, and that’s where I tend to run it. The boat is propped on the edge and will make 2450-2500RPM at WOT, depending on load. Also, the wife doesn’t like going slow, and although I have tried to convince her that it’s more relaxing to go 8 knots, she gets visibly antsy after an hour at low cruise.

The inside legs are usually done at 8-10 knots. The fuel economy is about .5NM/Gal (36 GPH) on plane, and around 1 NM/Gal at hull speed.

One big issue for me is noise. The current exhaust/muffler system is LOUD. The mufflers are horizontal “glass pac” style fiberglass cylinders. There is also a fair amount of vibration at certain RPM’s. I have worked the shafts, props, and replaced the Ace motor mounts, and DD mechanics have told me that they are quite smooth for 6-71’s, and I may be expecting too much. After a 6-7 hour run it’s REALLY nice to shut them down.

So to answer your question, I think I need/want something in about the same power range. The boat currently sits low in the stern when fuel & water tanks are 3/4 full or more, the boot stripe definitely going downhill toward the stern, i.e. it could loose a little weight in the stern without needing ballast.

[Author]

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