Grand Banks 42 with Cat 3208 435 HP ?

I am now into my second year of searching for a Grand Banks 42 (or maybe a even a 46) I'm going to look at a 42CL with rebuilt 3208's (435HP). I have read the 375HP version is a better choice and that the 435 version doesn't last as long. Maybe this is due to running boats/engines too hard? These rebuilt engines have slightly more than 300 hours. My hope is that maybe if they are run conservatively in a trawler then they will last? Do you have CAT 3208's with the higher 435HP? If so how are they lasting?
Thanks again.

I will say the 3208 is a good engine. They are not sleeved so I do think you need to pracitice due diligence on how they were "rebuilt". You are correct...running them easily will help them last longer. If it is truly a decent rebuild, AND you run them easily, they should last longer than you do!!!

There is nothing defective about the 435p 3208. If you run it around 100 to 150 hp it will live a very long time. If you run it above 375 hp it will have a much shorter life.

+1 on the above responses. But the problem is determining how the engines were run, hard and put away wet or easy and long lived. But if it was truly rebuilt 300 hours ago there hasn’t been much time to run it very hard. Or if the rebuild was a good one. A non sleeved engine need to come out of the boat to have been rebuilt. I would ask to see the receipts for the work and see if there are charges for removal and reinstall.

Thanks . I have hope for these engines. Supposedly they were swapped out engines, so originals were not rebuilt and installed back in. Yes, I had inquired about receipts and who did the rebuilding so I will see when I get there but again supposedly done in FL where I assume there are some good mechanical folks.
I once read about a GB42 repower and they said they had to remove the rear window frame in the main cabin in order to get the engines in and out so I'll be looking for some evidence of that type of work.
And then there is the rest of the boat to be concerned about once I am ok with the engines. I hope I can find surveyors this late in the season (that is in the Northeast).

Yes, a V8 isn’t going to go out a door since it is so wide. An inline 6 can usually be stripped down and go through a door. Good idea to look at the windows for signs of removal. Good luck, hope it works out for you.

tiltrider1 said:

There is nothing defective about the 435p 3208. If you run it around 100 to 150 hp it will live a very long time. If you run it above 375 hp it will have a much shorter life.

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Here’s my dilemma and I usually get 5 different answers: what’s the long term effects of running these at a lower RPM as far as carbon build up, etc. We have the 435s in a GB 46MY. I usually run them around 1400 RPM. Should we run them up to 2000+ routinely?

stiggy said:

Here’s my dilemma and I usually get 5 different answers: what’s the long term effects of running these at a lower RPM as far as carbon build up, etc. We have the 435s in a GB 46MY. I usually run them around 1400 RPM. Should we run them up to 2000+ routinely?

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Answer No. 6: Should be run at WOT, 2800 rpm, periodically.

CAT says to run the engines between 1500 and 2800 rpms. If you run at 1500 there is no need to heat them up. If you run them at 1400 then you should run them up to 2200 for awhile to properly heat them at the end of each day.

tiltrider1 said:

CAT says to run the engines between 1500 and 2800 rpms. If you run at 1500 there is no need to heat them up. If you run them at 1400 then you should run them up to 2200 for awhile to properly heat them at the end of each day.

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Thanks for that. Is it written anywhere by chance? Any other recommendations I’ll take whatever you got.

Not the same

My understanding of the 3208 lineup is that the larger horsepower engines got more than just big turbos slapped on them. There was piston rings and cylinder head redesign. I don’t have proof of this, simply what I’ve heard mechanics say, but I’m sure it’s out there if someone were to spend time researching it.
I’ve spent a lot of time running around on boats with 3208 engines. Clearly more modern engines are better, but these things are everywhere. As long as they get heated up occasionally I think you will be fine. After poking along in the ICW through no wake zones and bridges they usually start to get smokey. Then running offshore at 1500+rpm they clear up. Haven’t seen a mechanic once come out of an engine room and blame an owner for running lightly. It’s true that it’s not good, but I haven’t seen an engine failure due to that one reason alone. Maybe a combination of reasons will ultimately fail an engine, but simply running light doesn’t seem to do it.

stiggy said:

Thanks for that. Is it written anywhere by chance? Any other recommendations I’ll take whatever you got.

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It’s in the CAT Operation Manual. You can buy the manual from CAT. You can find the manual on line for a fee. I don’t think you can find a free source for the manual.

If you are serious about the boat get paperwork that defines exactly what took place with the “rebuild”. If you are lucky it was an authorized Cat dealer. 2nd, call a local Cat dealer and have them survey the engine (s). While everyone here is trying to help you you will get what you are paying for. A certified Cat tech is your best source of info.

Thanks for the comments. Now an update: Survey's complete, waiting for written reports. Engines are long block remans from Nationwide Parts Distributors Jacksonville (but was told the actual reman was done in WI). Installation work performed by Cable Marine also in Jacksonville. Engines were put through the port side window after the frame was removed. CAT tech did the engine survey , hit WOT at 2800 rpm and boost also good. Only item noted was a slight "tic" sound on port engine. Looks like valve lash adjustment was not done at the required 250 hours so hopefully that will take care of it.

The 3208 was originally designed as 220hp engines (or 210 depending on how it was measured). They are very good engines.

Over the years they kept bumping the HP which shortened the life span and reliability with each bump.

We have a 2001 GB46 europa. We have 4000 hours and have had zero issues. We run @ 1400 rpm and open up for 10 minutes every 8 hours or so. Have been maintaining per the manual. While doing maintenance on aftercooler, it cracked, so had to replace. Other than that, they have been very reliable. We typically run 150 hours per year but have done as many 300. Good luck with your decision.