If You Were Repowering...

[Art]

I would pull out the Twin Yanmar 64 hp naturally aspirated generator engines that are in my boat now, and replace them with the closest John Deere equivalent I could find. I would also like to add twin variable pitch props for slow trolling for salmon, and keeping the engines loaded at any speed. I would hope that the newer engine would burn cleaner and cause less air pollution, be a little smother, especially at low idle. I would also think the turbo would make it a little quieter.

About a year later when I started having problems with the electronics, the fuel pumps, the turbo's etc... I would deeply regret the whole thing and wish I had my simple old engines back.

Well put!

KISS!! Is the best way for most marine instances.

 

[alfamike]

Engine is out

Well had a few job related things & other delays slowed things down, but it is happening now..

With boats it never happens on time.

But the engine is now Out !

So re-power is happening as we speak.

Thanks.

Alfa Mike

 

[rslifkin]

This is an old one, but still relevant. In my case, I'd rip out the 340hp gas 454s and put in a pair of 380hp Cummins QSBs (either the reman 5.9 version or the newer 6.7).

I'd probably only gain a little on the top end as I'd be adding about 700 lbs along with the extra power, but I'd gain a lot of efficiency. WOT speed would likely go from 27 - 28 kts up to 28 - 29. By my best estimates, I'd go from about 0.55 nmpg to about 0.9 - 1.0 nmpg up on plane (and probably cruise comfortably at 19 - 20 kts instead of 17 - 18). At 6.5 - 7 kts I'd probably end up close to 3 nmpg compared to the somewhere around 1.2 - 1.4 I get now.

So with the 420 gallons of fuel I carry, I'd see a massive range increase. Enough that range at planing speeds would go from "occasionally limiting" to "not limiting for anywhere I should take this boat" and range at low speed would go from "plenty" to "more than I could ever need".

From a performance perspective, I wouldn't mind one of the higher output versions of those engines, but propping them would be a challenge. I already have 22" diameter props (2.57 reductions behind the 454s) and can't really go any bigger as I've only got 3.5" tip clearance to the hull, so just over the 15% rule. I'd be down to 3" (13%) at 23" diameter and forget going any bigger than that.

 

[FF]

Interesting thought. Ships and locomotives are often diesel electric, so why are recreational boats like those on TF not? Uneconomic? Other reasons?

Cruse ships choose electric so they can handle huge house loads when needed , and can have monster thruster loads at times. Diesels are very efficient at higher loads the generators are ganged for propulsion loads , and idle gen sets are kept fully warm to be put back in line rapidly when needed..

Railroad loads are huge getting a mile long string started , and electric does way better than a gearbox would.

IF a non boater was in charge of the funds , I would require the for the new engine the engine mounts to be replaced , along with what holds them ...the hull.

IF I have another boat built it would be a "box boat " designed to fit in a std 40ft cargo container. I have done my share of ocean crossing , frequently splendid , but always very time consuming. With the cost of so many boat engines near $30,000 each I think the cost of an under 100hp (so no electronic anything) engine and the boat constructed for the cost of a pair of big buck diesels.

With computer aluminum plate cutting and a very modest budget for outfitting requirements , it could even be assembled in the USA.

 

[Ken E.]

I repowered 6 years ago, removing 8v71n Detroits / Allison gears and replacing them with 210 Cummins remans and Twin Disc's. I run the boat at displacement speed so that's all the hp I need, by far. The goal of the repower was to take me reliably up and down to SE AK each spring and fall, and chase fish during the summer while up there. The Cummins are mechanically controlled and don't have intercoolers, a significant maintenance item on these engines. With 1400 hours, I'm completely happy with this setup and it has been trouble-free.

On the Detroits that were removed, aspirated versions of this engine, like mine, will run a very long time, especially if maintained and run easily. My concern was mostly with all the old hang-on parts...starters, alternators, pumps, manifolds. And both engines had low compression and low oil pressure. Having said that, though, I wouldn't be surprised if these Detroits would have gone thousands of more hours. I sold them to a guy running fish boats in Alaska and they're probably chugging away in another boat. I just wanted trouble-free operation on these long Alaska trips and I'm glad I made the change to zero-time machinery.

Further to the OP's question about what the choice would be if cost was no object, i wouldn't change a thing in terms of different engines, HP, or gears.

 

[Pete Meisinger]

Although I didn't have a rich uncle or anyone else to fund my repower project. Once I came to grips that a repower was needed I resolved myself to the fact that price had to be no object. Sort of a once in a lifetime, dream come true project. "
Spare no expense ! Open checkbook, (pick up the phone, wait for the tone, ask for a loan)

I had my F.L. 2175 (120 hp) rebuilt from top to bottom, ALL new parts, done by the best shop in the area. I even had them replace parts which were functioning perfectly like the starter , alternator, air cleaner, etc. It cost $20,000 total, here is why I did it..

1) It's a great engine and now will outlast me.
2) The reason it failed was mostly my own damn fault.
3) I didn't want to go to tier II, or III or IV or anything complicated like turbos or
computers.
4) Parts and professionals readily available.
5) I know and understand the engine and can do most repairs by myself, even in remote
locations if needed.
6) The boat (36 foot Albin) and the engine were designed for each other.
7) I didn't buy a long block, or a rebuild from Bomac or American Diesel, or Craigs list,
or eBay or anywhere else for around half the cost because I wanted to do business
locally with people I can talk to or go visit. And now I know exactly what went into my
engine, all top shelf parts, no cheap imported junk.

pete

 

[Art]

I repowered 6 years ago, removing 8v71n Detroits / Allison gears and replacing them with 210 Cummins remans and Twin Disc's. I run the boat at displacement speed so that's all the hp I need, by far. The goal of the repower was to take me reliably up and down to SE AK each spring and fall, and chase fish during the summer while up there. The Cummins are mechanically controlled and don't have intercoolers, a significant maintenance item on these engines. With 1400 hours, I'm completely happy with this setup and it has been trouble-free.

On the Detroits that were removed, aspirated versions of this engine, like mine, will run a very long time, especially if maintained and run easily. My concern was mostly with all the old hang-on parts...starters, alternators, pumps, manifolds. And both engines had low compression and low oil pressure. Having said that, though, I wouldn't be surprised if these Detroits would have gone thousands of more hours. I sold them to a guy running fish boats in Alaska and they're probably chugging away in another boat. I just wanted trouble-free operation on these long Alaska trips and I'm glad I made the change to zero-time machinery.

Further to the OP's question about what the choice would be if cost was no object, i wouldn't change a thing in terms of different engines, HP, or gears.

Care to mention total cost?? Thanks!

 

[T210DRVR]

Let me preface by saying the newer emission control engines have issues and I would avoid all of them. For older pre emissions engines it would depend on the application.

For high horsepower planning hulls it would be a pair of Caterpillar 3406 mechanical injection engines.

For a displacement or semi displacement hull it would be a single Cummins 6BTA 250 HP. This version of the Cummins 5.9 is very durable, fairly efficient and have good parts availability. If twins were needed it would be a set of Lehman 120’s. Again, they are very durable and fuel efficient.

 

[Ken E.]

Care to mention total cost?? Thanks!

I hired a local shop, Tri County Diesel, which was agreeable to let me work alongside them. I stripped engines down to the heads, they lifted them out through the salon door with maybe an inch to spare. I cleaned and painted the bilge, and pulled out around 100 lbs of DD wiring, then traced and labeled the remaining DC wiring.

The engines, gears and misc parts were about $50k in 2014. Plus $50k in labor, including quite a bit of metalwork and welding for the motor mounts and exhaust. I used my existing shafts and props, going to 3:1 reduction to cope with the pitch that I didnt need. I was happy with the price tag and especially the finished product. PM me for specifics.

 

[Woodland Hills]

Do you think that having a sportfisher that cannot get up on plane has affected the resale value? Or was that not a concern for you?
I have seen a few planing hulls that have had 8 and 12 cylinder Detroit’s replaced with 6 cylinder Cummins, but I haven’t gotten any idea of what impact that has had on the boats value on the open market.
Also, how much weight was removed and did that make any stability difference?

 

[Art]

I hired a local shop, Tri County Diesel, which was agreeable to let me work alongside them. I stripped engines down to the heads, they lifted them out through the salon door with maybe an inch to spare. I cleaned and painted the bilge, and pulled out around 100 lbs of DD wiring, then traced and labeled the remaining DC wiring.

The engines, gears and misc parts were about $50k in 2014. Plus $50k in labor, including quite a bit of metalwork and welding for the motor mounts and exhaust. I used my existing shafts and props, going to 3:1 reduction to cope with the pitch that I didnt need. I was happy with the price tag and especially the finished product. PM me for specifics.

Thanks, Ken May you cruise in comfort forever!

 

[Sailor of Fortune]

Interesting thought. Ships and locomotives are often diesel electric, so why are recreational boats like those on TF not? Uneconomic? Other reasons?

Cruse ships choose electric so they can handle huge house loads when needed , and can have monster thruster loads at times. Diesels are very efficient at higher loads the generators are ganged for propulsion loads , and idle gen sets are kept fully warm to be put back in line rapidly when needed..

Railroad loads are huge getting a mile long string started , and electric does way better than a gearbox would.

IF a non boater was in charge of the funds , I would require the for the new engine the engine mounts to be replaced , along with what holds them ...the hull.

IF I have another boat built it would be a "box boat " designed to fit in a std 40ft cargo container. I have done my share of ocean crossing , frequently splendid , but always very time consuming. With the cost of so many boat engines near $30,000 each I think the cost of an under 100hp (so no electronic anything) engine and the boat constructed for the cost of a pair of big buck diesels.

With computer aluminum plate cutting and a very modest budget for outfitting requirements , it could even be assembled in the USA.

The elephant in the room on Diesel electric that no one seems to talk about on the yacht side at least is the power requirement when engine is shut down. Those electric motors need heat 24/7/365 to inhibit corrosion. One of the companies I worked for bought a boat with them. A former CG icebreaking tug with DE. Monthly shore power electric bill was just under $10,000 month keeping it warm,dry...

 

[Art]

The elephant in the room on Diesel electric that no one seems to talk about on the yacht side at least is the power requirement when engine is shut down. Those electric motors need heat 24/7/365 to inhibit corrosion. One of the companies I worked for bought a boat with them. A former CG icebreaking tug with DE. Monthly shore power electric bill was just under $10,000 month keeping it warm,dry...

Whhhoooaaa! TY for putting that co$$$t out straight!!

Constant heat needed... never knew that one.

 

[Lepke]

I had a diesel electric tug built in WWII. I didn't heat the engineroom and don't know anybody with similar tugs that did. Tug operated in the PNW in a coastal climate.
I like diesel electric, but it's expensive and complicated. I had 2 engines, 2 generators and 2 electric motors into a single reduction gear. The controls took up about 30 sq.ft. in a 100' tug engineroom. Other tugs of the same design and hull that were built with conventional propulsion had more room and used less fuel.
What I liked about the diesel electric was infinite control of the prop speed from dead slow to full speed and better response to speed or direction changes. As long as the mains were running, the propulsion generators also supplied the power (250v DC) to run lights, appliances, and capstans & winches. So no generator had to run.
Repower - a all mechanical engine. For me that means Detroit Diesel. I'd rebuild a 71 or 53 series with enough cylinders to avoid the need for a turbo. My current DDs are 70 years old. Parts are available world wide. On electrically controlled diesels - my Ford diesel pu just had the cam position sensor fail. They're so unreliable I carry a spare & tools. I got towed home, put in the spare and 2 days later the spare failed, so I got towed again, but this time no spare. Try that out in the ocean somewhere.

 

[Nomad Willy]

When repowering you have a chance to correct a mistake that was made w many (maybe even most) trawlers. Being overpowered.

Most people when buying a new trawler will be able to afford most any power option imaginable. People are most familiar w automobiles when it comes to vehicles and they need more power than they usually need so we have developed a mindset of “no such thing as too much power”.

When I repowered I tried very hard through much observing, comparing and researching otherwise to arrive at the power amount that would serve well allowing engine operation at fairly close to 70% power applied. I ended up w 37hp chosen. Was apprehensive that I’d underestimate and be stuck w an underpowered boat. This is something Willard got right among so many manufacturers that got it wrong.
Willard overpropped by 250rpm so actually only was applying about 32 to 33hp. I almost chose the 33hp engine but chickened out. Could’a done everything I’ve done through the years w the 33hp engine but I’m glad I chose the 37hp Mitsubishi engine. I think my load is very close to 50 to 55% achieved at 2300rpm cruise at 6.15 knots.

But w a SD hull one can power it for 7 knots and have a lighter (much lighter if a twin) more efficient boat w a smaller engine. But there may be a loss when reselling but the way things are going it could just as well be a plus. I saw (and have mentioned several times) a 36GB on YW that had been repowered w two 55hp Yanmars. Wasn’t that long on the market .. at least on YW.

But if you’re repowering you’ve only got one chance to get it right. And you’re in the drivers seat. No engineer or marketing man. And for you there will be no second chance.

 

[Wayfarer]

Money no object? Steam engines please!! (2) I would like the quiet and smoothness. Some kind of tidy burner system burning diesel.

Steve

Well now this is a fun and romantic idea. I'd love to listen to a steam reciprocating engine 'tickity-tocking' along down in the basement. Just think of the unlimited hot water supply! Oh, and the steam whistle! Might get a little toasty in the boat, though. Probably not the best option for cruisers in warmer climes.

In fantasy land, I'd just replace the current 1985 Perkins 4.236 with a brand new Perkins 4.236, which I don't think they make anymore. If that's not allowed in this game, then I'd want to stick with something under 150 horse, low tech, sturdy, reliable, simple to maintain and fix. I'd stick with the single engine and shaft. Pretty boring I guess.

In ultra fantasy land, I'd like an engine room elf. A small, agile creature, with a tough, durable hide, excellent night vision, and kind eyes. Engine room elves can fix anything. Not only do they know how to, but they deeply enjoy doing so. It's their sole purpose in life. The more hopelessly broken something is, the more likely it is that they'll be able to fix it, and the more they'll love doing it. Engine room elves are happy to live in small, dark, loud places, and enjoy eating the contents of black water tanks, so they never need to be pumped out. The elves' only waste product would be fresh clean diesel, which can then be added to the fuel tanks. I would name mine Perkins.

 

[Ken E.]

Do you think that having a sportfisher that cannot get up on plane has affected the resale value? Or was that not a concern for you?
I have seen a few planing hulls that have had 8 and 12 cylinder Detroit’s replaced with 6 cylinder Cummins, but I haven’t gotten any idea of what impact that has had on the boats value on the open market.
Also, how much weight was removed and did that make any stability difference?

A fair question on resale value, but not much of a concern. Frankly, I don't much care. I wanted a sportfish design because it's what we like to do....fish in Alaska, with lots of cockpit room in a stout boat suitable for that environment. I prefer going 8 kts not only because of the fuel saved but because of all the debris in the water up here. Whether any future buyer of this boat shares my values, who knows? What I do know is that I use the boat heavily enough that when I sell it, market price won't be terribly important - I will have extracted a huge amount of utility out of the boat already.

On the engine weight change, a DD871 weighs 3100 lbs bobtail. The Cummins weigh in at 1100 lbs. Hence, I took 2 tons out of the boat. The boat was noticeably tender after the change in the follow-up sea trial. So, I contacted Hatteras, who suggested how to re-ballast. Long and short, I added 3000 lbs fore and aft of the engine room. Problem solved.

 

[Comodave]

Yes, most people will never see recovery of repower costs. They do it because they love the boat and want newer or better technologies in the engine. I love the 6B Cummins engines. I have a 6BTA in our motorhome. I hope to never have to repower but I have spent /over spent on our current boat but we love the boat and can’t go any larger or else we have to change boat yards. I don’t want to do that because our current yard is less than 1 mile from home and I go all through the winter and work on my boat. If I got a larger boat we would have to store it about 1.5 hours away and in the winter the drive would suck.

 

[MYTraveler]

Pretty happy with my 660hp QSM 11s, but do wish I had put in the continuous duty, wet turbo, 450hp versions.

 

[Jmarsh203]

I’ve got ford Lehman 120s in my boat now with velvet drives behind them, I’m not the biggest fan since they are such high maintinence engines, other than being high maintenance I don’t have any big gripes about them. I’m thinking Cummins 6B’s with twin disks would be a pretty good and cheap swap with some twin disks. Some jd6068df150 naturals would be awesome as well if they fit, but I’d have to take some measurements to see if they would, I haven’t looked since I know I can’t swing the cost of them right now. I’m a huge jd6068 fan, they are probably the best motors in that class and size range. The company I used to work used 6068 generators exclusively and I’ve never seen an engine put that many hours on with as little maintenance as them. The boat I rode for 3 years had 43,000 hours on one generator and 44,000 on the other without overhauls on them. They would get oil changes every 500 hours and would run for one week straight at a time, we would swap generators every Sunday. After running for a week they were both consistent in needing to be topped off with one gallon of oil. I read back through the maintenance records on them from when they were installed and they were fairly consistent needing an new idler pully every about 15,000 hours and every 5,000 hours they would get a valve adjustment, one of them also needed a water pump I believe at around 25,000 hours. So I’m pretty impressed with them after a track record like that.