Younger engines or older with updates?

[chrtucke]

My question may start a firestorm of disagreement but I'm really at a crossroads as it were and would like some feedback, see below. We are in the market for a catamaran and have identified two identical boats that we like but there are some core differences.


Scenario:
If you were trying to decide between two identical boats at essentially the same price point (catamarans coming out of charter from two reputable companies) which are the same year, make and model…essentially the same basic level of care (and while assuming good regular maintenance on both etc) with same basic equipment but one had more engine hours (7000 hrs) on it than a second (4000 hrs) however, the higher engine hours accompany new transmissions, new cutlass bearings and new heat exchangers along with some other more minor peripheral items…which would you choose? Essentially just assume all things being equal accept the additional hours and work having been put into one and not the other.

Please be honest and tell me if I’m being a fool for leaning towards the higher engine hours. In my defense it does have a few other nice updates/upgrades aside from the engine work as well. : o)

[skipmac]

To a great degree it would depend on the engine. All diesels are not created equal. Some diesels are heavy, low speed, commercial grade engines that can easily go 10-20,000 hours . Some diesels are designed to be light weight, high output, high rpm and could be ending their useful life by 5-10,000 hours.

So first question, what diesel and do both boats have the same brand and exact same model (there can be variation in model to model even within the same brand)?

Bottom line, I would get a mechanic to check out the engines very carefully before making a decision. Probably don't need to say that his is an area where it could cost you a lot if you guess wrong. Just a rebuild, unless you do it yourself, could cost many thousands per engine. New, if a larger engine could easily top $10,000.

[captain58sailin]

With the lower engine hour unit, one could assume that you have a longer period of time before major maintenance need be applied. I would be biased towards the lower hour unit. You might want to look at what you think your usage might be. The 7000 hour unit that has the upgrades, probably needed them due to abuse etc... or just higher usage. It would be like buying a rental car, you already know that the previous operators were not as careful as an owner might be, so the one with the lower hours has not seen as many different users and hopefully wouldn't be as beat up. In any case I would get a thorough machinery survey and assessment, by an independent 3rd party, before making the decision. Ask for any oil sample surveys that might have been done. Depending on the company, they may have regular oil sample readings taken and have a file somewhere on it.

[Terra Nova]

They are both high hours.

[chrtucke]

I'm sorry you're right...those details should have been in the first posting. Yes, all four engines are the same, Yanmar 3JH-4E. One reason I'm not automatically going to the lower hours motor is that I do have faith that with regular/decent care a small Yanmar like these can run 10,000+ hrs pretty easily. I am also figuring that the peripheral work done on the one vessel is likely to be needed in the not so distant future on the other having both been in charter. However, as one reply states the lower hrs should indicate less use in general and could mean years more use before needing any of this work. Someone also had a good suggestion to check with the charter companies and see if they have any oil sample records from these motors etc. Thanks for your input...

[skipmac]

Originally Posted by Terra Nova

They are both high hours.

Well if you were talking about a GM 6-71 (admittedly not too likely in a small catamaran) even 7000 hours would not be considered high hours since that engine could easily give you 20,000 hours before needing an overhaul.

On the other hand, the OP says the engines are Yanmars which may be a whole different matter. I have to plead ignorance on the various Yanmar models but my general impression on their small marine engines is that they are on the low end of the expected MTBOs so 4-7,000 hours could be pretty high.

Maybe a Yanmar expert can chime in.

[skipmac]

Originally Posted by chrtucke

I'm sorry you're right...those details should have been in the first posting. Yes, all four engines are the same, Yanmar 3JH-4E. One reason I'm not automatically going to the lower hours motor is that I do have faith that with regular/decent care a small Yanmar like these can run 10,000+ hrs pretty easily. I am also figuring that the peripheral work done on the one vessel is likely to be needed in the not so distant future on the other having both been in charter. However, as one reply states the lower hrs should indicate less use in general and could mean years more use before needing any of this work. Someone also had a good suggestion to check with the charter companies and see if they have any oil sample records from these motors etc. Thanks for your input...

As noted, I'm no Yanmar expert but if the expected life of this model is +/- 10,000 hours I would be a bit hesitant to go with a 7,000 hour engine unless there was a significant saving over the other. New engine installed could easily run $10-$15,000 times two. I would also consider your planned usage. If you will be sailing the boat and uses the engines mainly to get in and out of the harbor, have alternate charging so won't run the engines for that AND can save a lot on the purchase price of the boat AND all the other goodies are in decent condition then it might make sense for you.

Regarding the transmission and other engine peripherals, get an estimate on what it would cost to do that work on the boat with lower hours and then compare prices. Unless they're old and out of stock, manifolds and transmissions are usually a lot cheaper than engines.

[a64pilot]

Assuming these were bare boat chartered, I think 7000 hours is maybe getting close to the end myself, but as someone else said, they are both high time engines, price accordingly.
the boat with 4000 hours tells me the whole boat may have much less use than the high time boat too