Rebuild vs Repower

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I think the argument that a large engine is as much efficient as a small engine at a slow speed is not entirely correct.

The difference is negligible at the same power output but the actual power required to move the boat at that speed is very small. maybe a large 370 Hp motor simply can not give you that little power even at the idle speed so this is where the much lower consumption comes from.

Et cetera, etc etc etc...


But spending north of $60K to save 1 GPH (or whatever) would take a loooonngggg time to recover.

-Chris
 
But spending north of $60K to save 1 GPH (or whatever) would take a loooonngggg time to recover.



-Chris
Right. Would take 15,000 running hours, or the lifespan of the engines. If running the boat was an 8-5 full time job, would take 10+ years..

BTW - I crewed on a Willard 40 with JD4045T from Long Beach CA to La Paz MX (1000nm) burned roughly 200-225 gals, or 4.5 to 5.0 mpg. Spending $60k to get 2 mpg doesn't sound great to me.

Here is the boat - its offered at $45k and under contract, presumably to the OP.

https://www.yachtworld.com/yacht/2002-mainship-430-trawler-8253573/

Interesting warning from broker (below). Engines aren't the only issues in thr OPs "worst case scenario" . Took on water that didn't go over stringers but damaged the sole? Hmmm.... Wonder if the generator survived ?

It is reported the vessel was not properly winterized, one engine is locked up other starts and runs.*

Vessel took on some water, it did not go over strings but caused damage to salon floor and other areas.*


Maybe this waa a buy-back from an insurance company that totalled the boat.

Good luck. High risk venture.

Peter
 
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Vessel took on some water, it did not go over strings but caused damage to salon floor and other areas.*[/I]


Wonder how water could damage the (aft cabin, maybe?) sole and NOT go higher than the stringers.

-Chris
 
> But spending north of $60K to save 1 GPH (or whatever) would take a loooonngggg time to recover.

No, not paying $60k to save 1 gph - the math does not work.
the question was - rebuilding the large engines vs putting in smaller engines if the cost is the same.
so, technically, in this case, it would cost me nothing to get extra 1 gph if i go with smaller engines.

the only cost would be lost resale value later but it's also debatable because, for me and a few people who replied in this thread, smaller engines with much better fuel economy and double range are more desirable than getting that floating cottage on the plane once or twice.

> Wonder how water could damage the (aft cabin, maybe?) sole and NOT go higher than the stringers.

The flooding from the clogged drains in the cockpit did not reach the engines. the cabin sole was wet from some leak from the top and it's not that bad - pretty usual for the old boat which got a leak but not repaired. "being there, done that" not my first water damage to be repaired to look as new.

i am assuming the worse case with the engines until I know otherwise.
so there are things to work on which is as much fun for me as boating itself and I see great potential in that boat and want to save her.
 
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I hope you will share your whole project here as you go through it. It will be real interesting to see what you find. You are getting it at the right price, and have some room to get it fixed up. As long as you can do much of the work yourself, it could work out well.
 
One thing you must remember, changing the engines means new props etc, new exhausts , new hoses new shaft couplings, there will be lots of other changes besides the engines etc. These changes will add many thousands to the costs, its not just the engines themselves. I think other members have covered the other more obvious disadvantages.

My gut... stay with the Yanmars
 
Just looked at the pictures in the listing. Were you able to check anything on the engines or generator? It looks like the water came up to just above the engine mounts, based on the residue and rust around the ER. Did you pull the dip sticks to see what was in the oil pans? Or try to bar over any of the engines? Any sense of how much electrical equipment got submerged? If it was the result of a plugged deck drain, then presumably it was all fresh water which is good. What's involved in getting those engines out, if that's what's needed? Are there hatches in the salon floor, or do you need to cut an opening?
 
I am rather dumbfounded that a winterization failure on one engine (the other starts and runs according to the listing) justifies ripping both out and rebuilding or replacing them with new Yanmars or smaller Betas.

Just think about what might have been damaged- all of the raw water flooded devices: main heat exchanger, tranny cooler, after cooler and lube oil cooler. All of those can be replaced for roughly $10,000 and it is highly doubtful all have to be replaced.

And at an asking price of $45,000 vs market of about $200,000 for a similar boat in good condition, you have lots of money to deal with surprises.

So do it right and stick with the Yanmars unless you want to have a $100,000 boat powered with Betas that you can't resell.

David
 
My gut... stay with the Yanmars

Yes, this is my plan A unless the actual quote for fixing Yanmars will be much more than i expected. I checked some prices for major components for those engines and they are in the tens of thousands just for the part so 60k for rebuild may be too optimistic. hopefully, it will not be required as others mentioned.

New Betas 85T are $49k for both engines including transmissions.

i will not make a decision until I have more exact numbers so my assumption for this thread was the cost will be the same in both cases.
 
If you check N41 sea trial data (it was not on smooth water and the boat was pretty loaded), they got 2 mpg at 7.4 knots with 46% of power from Betas 85T:
Is what you posted

Here’s some real world numbers from the sea trial of our NT 42 on a choppy day run at all cardinal points.
6.8 kts 1030 rpm 2.3 gph
Now the NT weighs more then your Mainship but not as much as the N41. Also it has a 540hp turbo, common rail, after cooled Cummins C so is a more complex engine than the yanmars. We’re also carrying a lot of extra weight from published numbers (gyro, full tanks, extra infill). Still as multiple posters have pointed out regardless of what you do you still have a SD hull. Your engine choice will have no significant effect on efficiency. It’s the hull that matters not the engines. If you want efficiency per unit of displacement your only logical choice is to change your hull not your engines. This is like wanting to make a Lamborghini into a rock crawling 4x4. Piss away all the money you want ain’t going to happen.
Now the N41 is a sea boat. The Mainship isn’t. They are built entirely differently. Hell they couldn’t even put a fly on the N41 and keep a “A” designation. The N can’t go the wrong way through a current. Be it the East river in NYC, CC canal or many places on your loop. It’s defense unlike the Nordies in weather is to avoid. Sometimes that means speed. Same with dealing with coastal traffic. Your ability to dodge and just get out of the way is lost. Regardless of what you do it not “a poor man’s Nordie”. Your destroying the value of the boat. It’s safety factor as well. Imho just not a logical decision. Even at $60k v $100k.
 
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As far as the Beta 85 vs 115, I think they just don't offer the 115 in the US at all. Emissions-wise, anything you put in has to meet the same tier level that the original engines did, but as long as it's equal or higher, you're good to go. So nothing would stop you from putting in a different set of similar (or newer) Yanmars, or swapping to Cummins, or whatever else was deemed most cost effective if the current engines are actually shot and can't be rebuilt for less than the cost of new ones.
 
Just looked at the pictures in the listing. Were you able to check anything on the engines or generator?

Apparently, the generator's heat exchanger was damaged by failed winterization but it's an easy fix.

It looks like the water came up to just above the engine mounts, based on the residue and rust around the ER. Did you pull the dip sticks to see what was in the oil pans? Or try to bar over any of the engines? Any sense of how much electrical equipment got submerged?

It looks like the most damage was due to bad winterization and not the water which did not reach the engines.

I made an offer assuming nothing works. That offer was accepted, so, if something works, I'll be happier.

What's involved in getting those engines out, if that's what's needed? Are there hatches in the salon floor, or do you need to cut an opening?

The whole floor can be removed and looks like enough space to get the engine up. The side doors look wide enough to take the engine out after removing a few components - I did not get to that measuring part yet.

Just think about what might have been damaged- all of the raw water flooded devices: main heat exchanger, tranny cooler, after cooler and lube oil cooler. All of those can be replaced for roughly $10,000 and it is highly doubtful all have to be replaced.

That would be my ideal solution for this project but I'm researching the worse case while I'm waiting to get more data to work with. Also, parts for those Yanmars are crazy expensive. I'd prefer Cummins or Cat but well, I'll work with what i have.
 
So nothing would stop you from putting in a different set of similar (or newer) Yanmars, or swapping to Cummins, or whatever else was deemed most cost effective if the current engines are actually shot.

I just do not think that boat needs such large engines for what i want to use it (Great loop, Costal and Caribians). For me, fuel efficiency and rage is much more important than power. I did 2500 mi in 4 months on Defever so the fuel savings will be much more significant than someone who does a few short runs across the lake every year (in this case, the speed will be more important than range or efficiency).

Still as multiple posters have pointed out regardless of what you do you still have a SD hull. Your engine choice will have no significant effect on efficiency. It’s the hull that matters not the engines.

Good point but I'm not sure this is correct. My Defever 41 had the same semi-displacement hull (i think they offered a large engine as an option at that time) similar weight and with a 170hp engine, i was getting 2+ mpg at 7.5 knots. This is the same power as 2x 85T Betas plus new engines are probably more fuel-efficient than the 1987 industrial Yanmar.
I'm not trying to get faster (when the hull shape will matter), I'm trying to go slower.

This is like wanting to make a Lamborghini into a rock crawling 4x4.

I think it's more like making a Lamborghini into Corolla and if I put a Corolla's engine into Lamborghini, it will be as fuel-efficient as Corolla.

Boat hull shape dictates the seagoing abilities and how the boat behaves in heavy seas but this is irrelevant here because even with larger engines you can not go fast in heavy seas anyway.
 
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Apparently, the generator's heat exchanger was damaged by failed winterization but it's an easy fix.

It looks like the most damage was due to bad winterization and not the water which did not reach the engines.


Is this what the broker said, or is this what was revealed/confirmed by inspection? No dipstick's pulled to see what the oil looked like? No checking to see if the engines can be rotated through two full turns? And what does "damage by failed winterization" actually mean, vs damage by the water ingress. The listing also says one engine runs, and one is seized. Any confirmation of that.



I'm just trying to understand what we know first hand, vs what a broker has told us which is somewhere between unreliable, and certain to be wrong. As an example, the listing says the water didn't rise above the stringer, yet there looks to be a pretty clear waterline above the stringers, and rust/pitting on the engine mounts. So it looks to me like the water rose maybe 6" above the stringers. It's hard to tell in pictures, but those mounts definitely took a bath.
 
I just do not think that boat needs such large engines for what i want to use it (Great loop, Costal and Caribians). For me, fuel efficiency and rage is much more important than power. I did 2500 mi in 4 months on Defever so the fuel savings will be much more significant than someone who does a few short runs across the lake every year (in this case, the speed will be more important than range or efficiency).


Keep in mind, the Defever hull was optimized for slow speed running. The Mainship, not as much. So even if you run slow 90% of the time, there are likely to be times where speeding up will just work better in some conditions (particularly if running an inlet, as the Mainship is unlikely to handle well at low speeds in a heavy following sea). FWIW, I'm coming from the perspective of someone with a planing hull that runs at displacement speeds most of the time (my boat's fastest sustainable cruising speed is at best slightly faster than a Mainship 430).

If you're dealing with fairly modern engines that are OK with running at pretty light loads / low RPM where you can run as slow as you want without issues, the fuel savings from going to smaller engines will be small (no more than 10% I'd expect) unless you're changing to a dramatically more efficient engine, which I don't think is the case here.

I'd take a look at the manufacturer's prop curves for your Yanmars, the Betas, and maybe a couple other choices. I'm betting that once you estimate how the boat will be geared and propped for each choice, you'll find that the fuel burn at say, 7 kts is pretty close between the choices.

As far as engine choices, I'm pretty sure Mainship offered a few choices from the factory in that boat including B series Cummins. So if the Yanmars are truly shot, you may have some other fairly easy swaps to explore that may be cheaper than rebuilding or replacing the Yanmars and would require less surgery than putting in something totally different.
 
Hard to imagine that having engines which weren't winterized would cause they type of damage requiring a rebuild, something doesn't make sense. Sure the HE and AC might be damaged, and perhaps the riser if it doesn't drain correctly but the block, bore, pistons and head/valves should be fine. Maybe the turbos need service or replacement due to some moisture intrusion, but that's about it. I'd do a compression check on them if possible and go from there. Perhaps they were damaged before by being overloaded? Even that is hard to believe with the low hours.

In any case, those are very nice engines, I would go through them fully, fix the issues and enjoy them.
 
I'm just trying to understand what we know first hand, vs what a broker has told us which is somewhere between unreliable, and certain to be wrong.

I'm going by the information from the broken for now until i get the boat and can do a more extensive inspection.

Keep in mind, the Defever hull was optimized for slow speed running. The Mainship, not as much.

Defever had a semi-displacement hull which was the same for their version with larger dual engines and it could kind of plane. So i do not think any slow speed optimization was in the hull shape. But the transmission and prop were designed for slow speeds and it would be the case with switching to smaller Betas.

Even that is hard to believe with the low hours. In any case, those are very nice engines, I would go through them fully, fix the issues and enjoy them.

Yes, that is plan A
 
OP, I don't know what the heck people are commenting about resale value. Silly.

So I've never owned a boat which cost less money to own than I originally thought, or less effort to refurb. From viewing the photos and reading the broker's comments and this thread as well, I've drawn perhaps a different conclusion. So let's set the picture straight so there are no delusions or misconstructions:

  • That is a complete and absolute project boat. It has so many hidden issues that you can't even imagine what will jump out at you when you start your rebuild. Bad engines. Bad genset. Wiring??? Rotted decks. Rotted core around windows and portholes. Fuel tanks??? Cosmetic issues are incredibly unimportant compared to the systems and core of the vessel.
  • Realize that everything the broker and seller are telling you is under-stated, or they are lying, or they are ignorant and don't even want to know.
  • Plan on bringing onto the hard for the next 2 years while you entirely gut the entire boat. Entirely! Rip nearly everything out of the engine space. All running gear.
  • Will need new, oversized rudders but it will always behave poorly in heavy following or quartering seas.
  • You'll come in with an offer of about $29k, maybe negotiate up to $33k, but it doesn't matter even if you get the boat for free because your purchase cost will be nothing compared to the rebuild effort, which I hope you're handy enough to handle yourself.
  • All of this OKAY! As long as you know all this and accept it when going into this project rebuild.
  • Definitely rebuild it with your little Betas. It will be your boat and I hope you plan to own it for the next decade or forever, considering the time and money going into it.
So the question is, are you looking for a boat which you can be up and running within a reasonable time, or are you willing to put several years of effort in while you plan for your upcoming retirement/life adventure?

Just my 2 cents with eyes wide open, not eyes wide shut.
 
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After looking at the photos and the listing, this is a cheap and good project boat.
Assuming you buy it for around $30-40K and enjoy doing a lot of the work yourself,
it's likely you'll end up with something decent after spending $60-80K more and
a year or two working on it. The engine that 'runs' will tell you much about the
other one, too. It probably took some water in from the exhaust and hydrolocked.
Boats seldom flood evenly. A day spent with a competent mechanic will reveal all.

All in all, you'll eventually have a good boat for a good price, especially in the
current market. Good luck and keep posting the updates. :)
 
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[*]That is a complete and absolute project boat. It has so many hidden issues that you can't even imagine what will jump out at you when you start your rebuild. Bad engines. Bad genset. Wiring??? Rotted decks. Rotted core around windows and portholes. Fuel tanks??? Cosmetic issues are incredibly unimportant compared to the systems and core of the vessel.

You just described my recurring nightmares in the last few days :nonono:

All in all, you'll eventually have a good boat for a good price, especially in the current market. Good luck and keep posting the updates. :)

Thanks, this thought keeps me going after the nightmares :speed boat:
 
OP, I don't know what the heck people are commenting about resale value. Silly.

So I've never owned a boat which cost less money to own than I originally thought, or less effort to refurb. From viewing the photos and reading the broker's comments and this thread as well, I've drawn perhaps a different conclusion. So let's set the picture straight so there are no delusions or misconstructions:
  • That is a complete and absolute project boat. It has so many hidden issues that you can't even imagine what will jump out at you when you start your rebuild. Bad engines. Bad genset. Wiring??? Rotted decks. Rotted core around windows and portholes. Fuel tanks??? Cosmetic issues are incredibly unimportant compared to the systems and core of the vessel.
  • Realize that everything the broker and seller are telling you is under-stated, or they are lying, or they are ignorant and don't even want to know.
  • Plan on bringing onto the hard for the next 2 years while you entirely gut the entire boat. Entirely! Rip nearly everything out of the engine space. All running gear.
  • Will need new, oversized rudders but it will always behave poorly in heavy following or quartering seas.
  • You'll come in with an offer of about $29k, maybe negotiate up to $33k, but it doesn't matter even if you get the boat for free because your purchase cost will be nothing compared to the rebuild effort, which I hope you're handy enough to handle yourself.
  • All of this OKAY! As long as you know all this and accept it when going into this project rebuild.
  • Definitely rebuild it with your little Betas. It will be your boat and I hope you plan to own it for the next decade or forever, considering the time and money going into it.

So the question is, are you looking for a boat which you can be up and running within a reasonable time, or are you willing to put several years of effort in while you plan for your upcoming retirement/life adventure?

Just my 2 cents with eyes wide open, not eyes wide shut.


He has already bought it, uninspected, based on the listing and brokers representation. Maybe not closed on the sale, but it should be considered a done deal.


A thorough cleaning and inspection will surface what's needed, and I agree that over time you always find more, and never less. If you want a worst case, the boat's value is the core value for the engines pulled from the boat, less the cost to crush the rest and haul it away in dumpsters.


I wouldn't do any repairs on anything until the whole boat has been thoroughly checked out. Like you said, tanks, soggy decks, leaking windows, water damaged electrics, generator, could all be problem areas, and each one could cost as much as fixing the engines.


BTW, if a mechanic looks at the engines and just says they need a total rebuild, don't believe it. I'd want to know exactly what's wrong. Ruptured heat exchanger? Ruptured aftercooler (if it has one)? Water in turbo? Ruptured raw water pump? Fractured mufflers? Water in cylinders? Water or coolant in oil? Oil in coolant? Water in transmission oil? Engine bars over by hand or not? How high did the water reach and what parts were submerged? And you need to know this for both engines and for the generator. If the generator end was submerged, then it's junk.


And is this a salvage or junk titled boat? Can it be insured? Whatever yard you do the work in will likely require that it be insured.
 
You just described my recurring nightmares in the last few days :nonono:



Thanks, this thought keeps me going after the nightmares :speed boat:


Just curious, was there a reason you weren't able to really inspect all this prior to purchase? I used to do this sort of thing with cars, buying cars that were broken and didn't run. Their value is disproportional low at that point because a buyer doesn't really know what it will cost to fix it, and typically doesn't want the risk or the hassle. But I would check them out really carefully and have a pretty confident about what was broken and what it would take to fix it. Otherwise it's not worth more than it's part-out value. The best one I paid 1/3 the market value, replaced the spark plugs where it was parked, and drove away in a perfectly good car.
 
Just curious, was there a reason you weren't able to really inspect all this prior to purchase?

And is this a salvage or junk titled boat? Can it be insured?

The sale is conditioned on my final inspection and the major things i will be looking for are structural damages, extra soft spots on the deck, cabin tops and flybridge, and fuel tanks integrity (they are aluminum).
The rotted core around the portholes can happen in any boat and even professional surveyors would have a hard time detecting those. And that is still fixable. As I know, this was not a usual issue for those Mainships.
for the engines, generator, electronics, and other equipment I'm assuming nothing works and will not even inspect it at that time. that's the reason I'm buying this boat at 1/5 of the market price.
if everything worked except one engine, it would be sold for at least half of the market price, not 1/5

it's not salvaged or junked title. the owner was in the army and did not have much time for the boat so it was used very little. His son does not have any interest in keeping this boat or getting it back into shape.

The boat spent most of its life in fresh water and most electrical, plumbing, and hydraulic are above the flooded line. I replaced and upgraded most of the plumbing and electrical system on my 1987 Defever anyway so this will not be much different but everything is a bit newer and maybe fewer things require replacement. plus no "upgrades" from the multiple previous owners is a big plus for me because on the boats of that price range those upgrades are rarely done professionally anyway and just complicate the patient's recovery.

I'm getting into this understanding that this is a project boat and may end up costing me more than I expect. This is not my first project boat, hopefully, not the last one. All the previous boats I restored are still on the water and being enjoyed by people, which is a much more desirable destiny for any boat than being crashed and dumped just because it looked dirty and something did not work on it.


In the worse case, I will entertain you for a few years with the list of unexpected and expensive problems I will find to scare idiots like me from playing with project bosts in the future :facepalm:
 
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The sale is conditioned on my final inspection and the major things i will be looking for are structural damages, extra soft spots on the deck, cabin tops and flybridge, and fuel tanks integrity (they are aluminum).

The rotted core around the portholes can happen in any boat and even professional surveyors would have a hard time detecting those. And that is still fixable. As I know, this was not a usual issue for those Mainships.

for the engines, generator, electronics, and other equipment I'm assuming nothing works and will not even inspect it at that time. that's the reason I'm buying this boat at 1/5 of the market price.

if everything worked except one engine, it would be sold for at least half of the market price, not 1/5



it's not salvaged or junked title. the owner was in the army and did not have much time for the boat so it was used very little. His son does not have any interest in keeping this boat or getting it back into shape.



The boat spent most of its life in fresh water and most electrical, plumbing, and hydraulic are above the flooded line. I replaced and upgraded most of the plumbing and electrical system on my 1987 Defever anyway so this will not be much different but everything is a bit newer and maybe fewer things require replacement. plus no "upgrades" from the army of previous owners is a big plus for me because on the boats of that price range those upgrades are really done professionally anyway and just complicate the patient's recovery.



I'm getting into this understanding that this is a project boat and may end up costing me more than I expect. This is not my first project boat, hopefully, not the last one. All the previous boats I restored are still on the water and being enjoyed by people, which is a much more desirable destiny for any boat than being crashed and dumped just because it looked dirty and something did not work on it.





In the worse case, I will entertain you for a few years with the list of unexpected and expensive problems I will find to scare idiots like me from playing with project bosts in the future :facepalm:



Well, it sure sounds like you are going about this the right way, and know what you are getting into. It will be interesting to follow along, and if anyone can pull it off, sounds like it will be you.
 
i'll keep you guys updated.
thanks for all the suggestions and opinions :flowers:
 
Agree that you sound experienced and that you are aware of what you’re getting into. I bet when you’re done it will be a fine cruising boat. Please let us know when that final day comes so we can start arguing over your choice of anchor!
 
After looking at the photos and the listing, this is a cheap and good project boat.
Assuming you buy it for around $30-40K and enjoy doing a lot of the work yourself,
it's likely you'll end up with something decent after spending $60-80K more and
a year or two working on it.

I might know a feller on here who bought a NOT-project boat (although with semi-neglected engine service) and still spent north of $120K fixing stuff.

Updating engine and genset service accounted for approx $55K of that, much of it labor he couldn't do himself.

Still....


In the worse case, I will entertain you for a few years with the list of unexpected and expensive problems I will find to scare idiots like me from playing with project bosts in the future :facepalm:

:)


Please let us know when that final day comes so we can start arguing over your choice of anchor!

What, why wait....

this one is easy - Rocna Vulcan 40kg/88lb

Too small, not enough chain [emoji3]

You all may remember I just replaced our tiny "previous owner replacement" anchor with a Rocna Vulcan 40 (88-lb). Biggest/heaviest candidate that would fit the existing davit. Untested, so far.

But yep, the current chain is too small, and not enough of it. :)

-Chris
 
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