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Not a whole lot of help on engine choice when it comes to that size but I own and volvo and they should at least buy you dinner if they are going to screw you that bad when you buy parts. 126 bucks for a 2 inch oil guage or 40 bucks for a belt it a little excessive.
I know it's an old argument but those Yanmars seem a little small (CI, weight, etc.) to be producing so much HP. But, same thing is said through their entire line. Also depends on which hull too.
Gonna come down to personal preference. I like the Yanmars. I can get them serviced (heck, I can service them myself) for cheap, locally, and they're reliable and barely sip the fuel... Almost everyone I know runs Yanmars. Not many Volvo's down here, but they certainly are excellent engines... Same thing as there, there are a lot less guys around who work on Volvos than there are Yanmars..
Haven't heard too much about the luggers, other then the fact that they're bigger and heavier than the cats... If I remember correctly, the 6170 is like a 5,000 lb engine....
If it was my choice, I'd go with Yanmars.
__________________
2011 Contender 21 Open w/ Yamaha F250B
Volvo and Yanmar both have sky high parts prices and parts can be a problem. Even on their little engines. I waited three weeks for an injector on one of their genset engines last summer!
Pay very, very close attention to parts pricing and availability. I'd be considering Lugger as others have mentioned as well.....
Yanmar's engine, if its the one I'm thinking of, is actually made by Scania - its not their design. There are some cool features though that could keep costs down over time - like individual cylinder heads.
Glassman - I automatically assumed that you were referrng to power for a sport fishing yacht but I should have asked what sort of boat are you wanting to power. Motoryacht, Sportfisherman, Passagemaking trawler? Commercial use? Single or twin? Length, beam, displacement? Planing hull, displacement or semi displacement? Custom built or a production boat? What performance characteristics are you looking to achieve? Thre are just SO many variables when it comes to marine power.
Not knowing what sort of service availability where you are located makes andy suggestions a guess, as far as that service is concerned. You may want to consult with Johnson and Towers to see what they may suggest for your specific applications. They have some very knowledgeable folks up there that have worked with many manufacturers for marine power applications.
There are a great many (very good) marine diesles available today in the HP ratings you mentioned. Specific recommendations will have alot to do with some of the questions I posed here. I would strongly suggest that you go to boatdiesel.com, for on that site you will find a much deeper wealth of knowledge about marine diesels and their various applications.
For another power option there is the venerable Detroit Series 60's.
Express Sport Fish, Twin Screw, Planing hull, Custom Built, 48' long 16' beam, 42K displacement.
As far as perfromance, I'd be content with 25Knt cruise and good fuel economy so I can get range to reach distant canyons.
I've been to boatdiesel.com, there are as many opinions are there are engines. I haven't considered Detroits.
A few thigs I don't like about the Yanmar is they are not available as lefts and rights, so you have to do service work on the outbaord side of one engine.
The hull you describe is nearly identical to Ocean Yachts 48 Sport Fish...... 48' 8" OAL, 16' 0" Beam, 42,500# Displacement. I am not sure of the degree of deadrise, but I have 8-10 degrees floating in my memory banks. If you are using a steeper deadrise, you will need more HP to achieve the same speeds as mentioned. The Ocean, with a pair of 660 HP Cats will cruise about 27-29 knots and top out around 33-34 knots. With a pair of Cat 3408's at 800-HP they will cruise around 31-33 knots and top at about 35-37 knots.
For your application, you may want to consider the MTU (formally known as Detroit) Series 60 in 700 to 825 HP ratings as well as the venreable Cat 3406E model in 800-HP. Both of these marine powerplants have a pretty decent reputation as far as reliability is concerned. In addition both the Cat and the MTU/Detroits are very easy to find parts and service for.....here and in the islands.
The Cats and the MTU/Detroits will most likely be more economical to purchase initially when compared to Lugger and some of the others. They are available rigged as "handed" engines so all of your filters and fluid check points are to the inside. I can recommend Johnson and Towers as a source of information on the Detroit/MTU, they have offices in Maryland and New Jersey.
I had a client that purchased a new Ocean 52 Super Sport (convertible) from me that was powered by the (then) Detroit Series 60's @ 825-HP each. This boat was 52' 7" OAL, 16' 4" Beam, 56,000# Displacement, 8 degree deadrise.... She would cruise at 28-30 knots all day long while topping out near 33-35 knots. (all cruise speeds are given at 90% of the max RPMs)
If my memory is correct (and believe me, that is gettng to be an issue lately!) I thought Yanmar had handed engine kits available....ones with a remote filter kit as well as a engine oil dipstick on the inner side. These may not be available for your application though. Mack Boring is a good source of information on Yanmar Marine Power...
I hope this helps..................Oh yea, check out Glendinning's Electronic Controls. good stuff.......they also have a manual back up in case you loose electrical.
Good Stuff. This is what I was looking for. Those are some good numbers for the Ocean 48'er. 31 to 33 Knts cruise would be great. I like the cruise they are getting from the 52' er. I'm not sure about service for the MTU's in this area. I'll have to check on that. I believe you are right about the Yanmar remote kits. I have looked at the Glendinning's Electronic Controls. Nice stuff also.
Looking for some edjucated opinions for an engine selection. I've looked at the Yanmar 720's 6 cylinders, Volvo D-8 800 and Cat C18.
I've had most of the big diesels in various vessels. I lean towards what I've got now a KTA50 (1600BHP) which does an excellent job for the size vessel. I would take a Man or a Lugger in a heartbeat if I had to change. But I don't.
__________________ Capt. George Woodward
Died 16 DEC 2007
send ecards to family c/o bquasuittuq@yahoo.ca
Good Stuff. This is what I was looking for. Those are some good numbers for the Ocean 48'er. 31 to 33 Knts cruise would be great. I like the cruise they are getting from the 52' er. I'm not sure about service for the MTU's in this area. I'll have to check on that. I believe you are right about the Yanmar remote kits. I have looked at the Glendinning's Electronic Controls. Nice stuff also.
You're welcome. Where are you located? I know is says "behind the keyboard" but that is where I am and I don't see you here! remember, if there is a Detroit Diesel dealer/service center near you, this is also MTU. MTU (Mercedes) bought out Detroit diesel....Detroit Diesel service should be available nearly everywhere, second only to Caterpillar.
Regarding CAT, the C-18 is 1015 hp and hence much larger and thirsty. In that range the C12A is a great motor at 715hp, very popular in OEM and repower situations. She burns 18 gph at slow cruise (1900) and 26 gph at fast cruise (2100). Weight is 2588 lbs vs. 3788 lbs for the C18. Awesome power to weight / power to size ratio. The C15A is now available in a 865hp version (3226 lbs) . The 60 series Detriots have been great in OEM applications with 825hp.
Beware the Series 60s - the block itself is great but there have been repeated failures reported of the intercooler, which is quite expensive to replace.
Compare warranty statements and see what's covered. You want a warranty that covers all the auxiliary parts (e.g. coolers, etc) as well as the major components (block, crank, etc) and includes labor to R&R whatever needs to be R&Rd.
Many warranties only include "all parts" for the first year - which bites if you start having problems with intercoolers failing, and suddenly you've got a $5k bill in your hand for a new one!
Man it's a tough decission. I haven't considered Cats because of all of the horror stories I've heard about the 3126's and Cats reaction to some of the problems.
I've found that CAT stands behind their product quite well. We've sold a bunch of boats new with the Series 60 and they've been great as well. CAT does offer a nice extended warranty program as well as a "used" motor warranty that makes resale pretty good on them.
I fish an older 45 Hatteras which was recently repowered with C12s. We get a solid 27 - 28 knot cruise and the economy has been great. The owner may add to this thread when he sees it. He went through this same decision process so his input may be useful.
The problem with all the newer technology engines is that there just isn't enough "in service" life to know with most of them.
Unless there is a MAJOR problem with the design you don't start to see people cursing for 3-5 years after a new engine is introduced in the recreational market. That's because most people run 100 hours a year, so the time doesn't get to where things start to go bad until then.
Unfortunately that's about when warranties run out too, and then things get REAL interesting. There are exceptions - MANs that were eating pistons, sometimes on the sea trial after a rebuild - CATs that had "soft block" problems and started eating oil at 200 hours, etc - but in general the "aw @#$#$" problems start showing up around 300-500 hours, if there's some major problem with auxiliary parts and such.
I'm aware of multiple reports of Series 60 intercooler failures, including more than one on the same boat. That guy runs commercially, and puts more hours on in a year than most of us do in five. He had two failures in one year's time, and DDC/MTU refused to warranty either. Needless to say he's REALLY unhappy as that's 10 big ones out of his pocket that were completely unexpected, and he's got no confidence that there won't be a third! I can't validate this as something that will bite ALL owners (there may be something specific to his install that is causing problems) but that's an awfully odd failure to be related to installation issues.
And there's the problem in the end. You have a lot of anecdotes but not enough of an installed base to know if you're looking at a pattern or an anomaly.
For that reason I say compare WARRANTIES very, very closely, and compare service and parts prices. You're talking about spending north of 100 big ones here - engine suppliers should be falling over themselves to give you what you ask for in that regard. If they won't then you KNOW they are aware that their engine doesn't compare well.
What I'd ask for is:
1. The FULL warranty statement for each engine under consideration.
2. A full list of parts and current prices to do a complete overhaul., AND a full list of parts and current prices for all "routine" maintenance per the schedule, along with the schedule itself. In addition you want a list of all parts and current prices for all "wear parts", whcih means all coolers and other parts exposed to seawater (e.g. raw water pumps, etc), at minimum.
Now sit down and start comparing. Look first at the warranties - what's covered, what is not. You may be able to eliminate one or more engines right here.
Then go look at your parts lists with prices. You'll discover real quick what the total cost of ownership is like.
Finally, look at the hp output per CID of displacement, and apply the following "rule of thumb" for how often you'll end up NEEDING to rebuild, assuming you run at 200 RPM off the top for "fast cruise":
or, for any of the above, 10 years, whichever comes first.
You may do better, you may do worse.
Note that if you run 100 hours a year it doesn't matter what the displacement/hp ratio is (now you know why the engine guys crank up the output!)
But if you run 300 hours a year, suddenly it DOES matter. Now for any displacement over 0.9hp/cid, you potentially will eat majors before the 10 years is out.
If you run 500 hours in a year, then it REALLY matters, because now you are virtually GUARANTEED to need to major the engines.
(Now you know why the commercial guys scoff at these high-output engines!)
With all this you can do an honest "total cost of ownership" sheet - and that, at the end of the day, is what matters.
An engine that is $20,000 cheaper is the most expensive of all if you end up overhauling it twice while you own it!
Best new diesel between 700HP-1000HP 
