Thoughts?

Hello;
We have a Roughwater 37 that we just love. The boat is a 1987. This is the Sport fisher model so it is a semi displacement hull weighing in at under #20,000.
We have the original Detroit 8.2s 250 hp, with 2:1 gears and it is time to repower!
With the current set up we cruise at 8.5 knots at 1750 RPM. 15 knots at 2400 and 22 knots WOT.
I have a chance to purchase two Ford 275 HP diesels that were marinized by Mermaid Marine in Britian at a great price. They are fully rebuilt down to new liners and pistons by a respected shop and come with 1.23:1 gears. As Mermaid is still in business all marinized parts are available (I checked), all be it shipped from the UK.
I am wanting to hear thoughts on this. I get that a modern motor woud be lighter but given the design of the RW I would need to add ballast if I went much lighter on the engines. The builder of the RW ignored Ed Monk Jr's advice on the flybridge and built them a tad top heavy. Fine with twins but it adversly affects the roll performance on single engine versions. The Fords are 80 pounds lighter each than the 8.2s and look like they will fit no problem. I have 1 3/4" shafts so that should work... Most likely will have to repitch the props, the size looks OK according to a prop calculator.
I will of course have to modify the existing mounts but that is easy as they are steel attached to the main stringers.
I would love to hear thoughts or advice. I think that I will lose a knot or two of speed but I really don't care as we rarely operate the boat above displacement speed. The Detroits have served us well but are starting to have a lot of minor issues and it is impossible to find a tech in our area. Parts are also pretty hard to come by for the J&T bits.

Don't do it.

Detroits are still serviceable and repairable, even rebuildable. Changing engines and other issues you might face is a tough course and fraught with potential problems. I just think more trouble than worth.

I cannot find anybody willing to work on the Detroit 8.2 in all of Oregon. I used to have a guy who worked at a truck shop who would work on them but he retired. I know of one shop in Seattle that will work on them but that is a four day trip crosssing the Columbia bar and 200 miles of Pacific Ocean. No one in the PNW will rebuild a 8.2.
Which is really too bad. I know that the 8.2s have a reputation but we have 2,400 hours with no major failures. Just pumps, gaskets and one turbo. But they are starting to leak oil and I need a injector timing etc...

Which Ford engine?

It is the same as the Lehmans SP 275. Basically a ford Lemans that is marinized by Mermaid Marine in the UK

The Fords are an excellent engine, we had SP225s in our last boat. In the Lehman version the aftercooler was made of unobtainium…. So make sure about all the parts availability. Our 225s just ran and ran. Never had anything beyond filters and oil.

Finnegus said:

I cannot find anybody willing to work on the Detroit 8.2 in all of Oregon. I used to have a guy who worked at a truck shop who would work on them but he retired. I know of one shop in Seattle that will work on them but that is a four day trip crosssing the Columbia bar and 200 miles of Pacific Ocean. No one in the PNW will rebuild a 8.2.
Which is really too bad. I know that the 8.2s have a reputation but we have 2,400 hours with no major failures. Just pumps, gaskets and one turbo. But they are starting to leak oil and I need a injector timing etc...

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Have you called Detroit Diesel?

If money is not a consideration, then it's an ok plan. But I know the Fords won't perform like the Detroits, even 8.2s. It's a lot cheaper to learn how to adjust your engines than replace them.

I'm sure there are people that can rebuild those engines in Oregon, it's a matter of finding them. If you call yards that cater to commercial boats, they probably have names or a mechanic in the yard. An engine kit is about $1500. And about the same to rebuild the heads.

THere is a fellow , MDS, who frequents Boatdiesel and advertises there.
He is a frequent contributor and knowledgeable about those engines.
Before giving up on the Detroits look him up on B.D. and contact him.
His site is Marine Diesel Service. He is out of state for you but regardless contact him as he has helped many.

An oil leak? Where? Many oil leaks are valve cover gaskets, pan gaskets, front crank seals, maybe a rear crank seal. Lot less money to replace gaskets than swap engines.

You will be surprised at how much work and expense there is to a so called simple swap especially when the engines are different.

You might even ask MDS about your thoughts as a consultant.

I have an old Cummins, older than yours, and it too leaks oil but I am not thinking about changing untill the actual engine shows signs of wearout.

IMHO, Oil leaks are a nuisance, not a cause for a swap.
Due to injectors I changed the valve cover gaskets and the new ones slowed a lot of oil.

I have had many conversations with MDS on Boat Diesel. He has been a great help. I should mention that this is not my first repower. There is a lot I like about the 8.2s but they are seriously hard to service and jammed so tight in the engine compartment you have to drop the exhaust and crawl over the batteries on your side to reach the outboard side of them. Think about that when you suggest that I can adjust the injection timing, which involves baring the engine over for each injector before using the detroit 8.2 magnetic dial feeler gauge to set them.
I contacted my local Detroit Dealer asking if he knew of a tech, he said "no" and "the 8.2 is the worst engine ever put in a boat." He recommended replacing with Cummins 6bta. That is a great engine but one cost more than both of the Fords with gears and guages.
I have a friend with a rigging and crane company so I will be doing the swap myself.
Our last boat I replaced a shot Perkins Range 4 with a DDC Volvo. It was a real pain in the stearn. I dont think it will be easy.
My hesitation is more about the match of engines to boat. The Ford's were in a Bertram charter boat that was decommissioned due to hull structural issues. They have been recon'd and certified by the shop.

If you do end up doing the swap, please make a thread on it and document it with photos. I think there would be a lot of interest in it.

"the 8.2 is the worst ( detroit) engine ever put in a boat."

8.2 are light duty truck engines , so last a long time if operated light , but do not like WOT .

Keep them if displacement speeds are OK, toss them if you need speed.

Well quick update... The deal on the Fords fell through and that was a lucky break. I happened to find two very clean 2006 Cummins 6bta 330s for a great price from a damaged vessel and purchased them. We are planning on going ahead with the re-power in April. The Cummins were a fantistic deal and compleat with gears, panels and all accessories. I will start a new thread once we haul the boat with progress. In the mean time any body need a couple of 8.2s? LOL

Finnegus said:

Well quick update... The deal on the Fords fell through and that was a lucky break. I happened to find two very clean 2006 Cummins 6bta 330s for a great price from a damaged vessel and purchased them. We are planning on going ahead with the re-power in April. The Cummins were a fantistic deal and compleat with gears, panels and all accessories. I will start a new thread once we haul the boat with progress. In the mean time any body need a couple of 8.2s? LOL

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Great find and choice! Good luck with the project.

I think you will be very happy with the Cummins. Lot's of good support, easy to work on and parts are reasonable. Spend some time on SBMAR.com for how to look after them and if you follow the advice they will give a long service life. Weak points are well documented and the required work arounds and maintenance is pretty well established.