can you change Cat 3208 to Yanmar 8LV-370?

My 24 year old port engine is toast after about 5000 hours (Cat 3208 TA 375HP). Planning to rebuild starboard and go with long block for port. Someone suggested the Yanmar as a "drop in" replacement. Anybody have experience with this?
I am replacing risers and have to run new wires to flying bridge. Just got new shafts so I would be willing to shorten them but not get longer ones.
Starboard engine is solid except low turbo boost. Waiting for prices etc.
Cutting new and bigger door in salon to get engines out.
Thanks for your comments.

Replacing the CAT with an equal rebuild one is not an option?

My question comes because 3208s are V8. Are Yanmar V8? Do you want to change both CATs?

I punched CAT 3208 in google and a bunch of photos from rebuild for sale engines come up from all over USA


Sorry for the ignorance

The Yammers are V8's. By the time I start getting into equalizing the starboard engine to a rebuilt port one (turbo, hoses, possibly heat exchanger, etc ) a rebuild is not much more. I want the engines to be as equal as possible for future sale. If I can sell the starboard engine (which to date has been very reliable) the cost to modernize the power train becomes more reasonable IF I don't have to get into major engine mount changes etc. If I go with Cat I know I am paying a premium but I will be confident I am not getting a spray paint rebuild.

I couldn't imaging not just dropping in a rebuilt 3208 from a trusted rebuild shop.


Now a total repower is not out of the question...but I am assuming money IS an object.

The Yanmar V8 is a new marinization of a Toyota car engine. Common rail electronic injection, I imagine half the controls are Toyota, half are Yanmar. Never like it when responsibility is shared between two companies.

I would consider it an unproven machine with regards to the US market. something goes wrong with it, most mechanics will stand there scratching their heads.

Any mech can fix a 3208. Go with a reman on your blown one, get the other one freshened up. Seals, rings, bearings, etc.

Stay with "Plan A". Think of all the modifications and changes you won`t have to make.

If you go Yanmar, despite it being Toyota, which is a pretty good engine, it will be electronic and require a geek with a computer to tune it. The 3208s are like Lehmans (although V8s are a bugger to work on compared to 6 cyl. IMHO) you can do most repairs with a crescent wrench and a hammer. Cats and Cummins are horribly expensive if you have to do anything with a dealer, stay away and you will be much happier with the Cat.

Watch the mechanic, don't let him screw you. A boat dollar or two is easy to hide with a repower...

Factory rebuilt 3208s used to be $5,000.00 for the 210 hp units and had a caterpillar warranty. I would stick with the cats because of the abundance of parts available, dependability and the mechanics who are familiar with them, the other may end up being a orphan.


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You can go into most logging camps on our coast and there will be a couple of guys who can work on a Cat, probably even have parts. The Yanmar, no.

Tony Athens gave you a terse answer to your question over on boatdiesel- go with a remanned Cat. The underlying reasons are what Ski said above- unproven engine, marinization of recent Yanmar conversions have been poor, electronic engine, high rev power. Need I go on.


Stick with the Cat.


David

henrymei said:

Someone suggested the Yanmar as a "drop in" replacement. Anybody have experience with this?

Click to expand...

I do.

That "Someone" is better known as the good idea fairy. He seems to show up every time what should otherwise be a dirt simple choice needs to be made. The good idea fairy's mission in life seems to be to over complicate every situation he is allowed into. I cannot stand that sorry sap and am glad to hear he's running in your circles now and hopefully stays out of mine.

Stick with the CAT's, unless you have more money than brains. If that's the case go with the Yanmars and make some lucky mechanics year a lot brighter.

Cat 3208 TA 375HP\

If you dont spend much time at flank, and do not need 375 hp, installing a factory rebuilt non turbo might make sense in terms of cost , longevity and fuel burn.

May not tow water skiers tho.

Was the Toy/Yan designed as a "drop in 3208 replacement"? No,?
Then for someone to say it is a drop in replacement means they are likely talking through their hat.

You will be into a full on repower meaning the engines will be about half the cost, maybe less. At this point there is little/no history of this engine in marine service.

The 3208 parts are still available. As suggested re-mans are still available.
If you really want two fresh engines then that would truly be a drop in replacement with a good history and future good sevice availability.

An update

The engine saga continues at a snail's pace. After sending a large deposit in to the local CAT dealer I was told there is no delivery date for a remanufactured long block. The price ballooned to $34,000 an engine with a one year parts warranty. An additional 3 grand for overhaul protection coverage. Alban CAT seemed happy to return the deposit and ship the engines to T&S Marine in Crisfield, MD for rebuilds at less than half the price. T&S has been suggested by several knowledgable resources. The Alban techs, who seem quite competent, will do the engine reinstall. The local watermen use T&S and swear by them.

henrymei said:

The price ballooned to $34,000 an engine with a one year parts warranty. An additional 3 grand for overhaul protection coverage.

Click to expand...

I had a similar experience with Cat. I bought a boat with twin 310hp 3208's and seeing they where tired thought I'd get them overhauled before we started using her. A friend of a friend from the local Cat dealership came out and quoted me no more then $15,000 each worst case and probably less. We shook hands on it (first big mistake) and he took the engines away. I rang a couple of weeks later to see how they were going and he wouldn't say how far along they were but wonted to have me come in and sign a quote (which I thought foolishly we had already agreed on).

Long story short they wanted $27,000 each so I told them to keep the engine and shove the quote. I ended up getting them back for the cost of stripping from the dealer and got another company to do them for $17,000 each including what I paid the dealer.

I've never trusted Cat since then and have tried to stay away from them.

Sorry for the rant. I'd get a rebuild from a quality shop to replace you old one. Repowering with a different brand is always problematic and expensive.

If you could put in a Yanmar, you would have some serious considerations to look into. Not the least is that the Yanmar is about 800 lbs lighter than the cat. So going with one cat and one yanmar would require adding hundreds of pounds of trim ballast. Also the 370 hp yanmar is a 3,800 rpm engine while the cat is a 2,800 rpm engine. So you would have to run two different props (available gear ratios are also likely different) at different engine speeds. It would be a royal pain to get the power output from the two engines the same.

If you want to change to Yanmar, do both engines.

Update

The engines were rebuilt by T&S in Crisfield, MD. A little over $28,000 including freight for both. The MG 507's were remanufactured by Great Lakes Power, the Twin Disc distributor for just over 12,000. So for $40,000 I have rebuilt engines and transmissions. Had new risers fabricated also. Painted engine room, replaced insulation. Things are looking good. Now hoping everything runs as good as it looks.

Henry: How were the cylinders done? Over size bore?

All cylinders were bored and sleeved. All new pistons. Aside from the one cylinder that broke all were in pretty good shape. criss cross scoring to promote lubrication was visible on the cylinder walls.

Got a few T and S 3208's running around here. They are all doing well.

Henry, good conclusion.

Henry, if you don't mind my asking. How did you/they get the engines in/out of the boat. Hatches? window? any pics of the process?

I will try to post pictures later. We removed two longitudinal stringers and cut an additional access hatch in the cabin sole. There was no port side door so we cut a rough opening for a sliding door and removed the window. A fork lift was used to get the engines in and out using a chain hoist. The clearance was tight. The boat was beam to a bulkhead at just the right height. Not too much tide to worry about.
A new door and frame was fabricated. The window will be recut. All in all a major project. The engines and transmissions weigh about a ton. I had a consultant who was involved in the original construction of the boat and a surveyor available as well as the yard crew. I am comfortable that we will have a seaworthy and aesthetic restoration.

Hi Henry.

Night Magic is a beautiful craft. Good Luck from here in.

Regards.

David.

Major project would seem to be a great understatement. Makes my head spin to even think about it. My cats are fine, I was curious how you did it as I may have to remove mine to get at a fuel tank with a possible bad fitting. If I have to go through what you did I think I would sell, take my beating and move on. Looking forward to pics if it isn't too much trouble.

Sounds like a well done rebuild. Keep all the details for when you eventually sell. There are many levels of "rebuild" performed in the market and yours being well done should have significant added value.