Repowering: Cat 3160 -> Cat 3208

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Nzdrew

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Joined
Jun 18, 2021
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17
Hi all,

I am looking at an old GB with twin cat 3160s with 4500 hours on them since the last rebuild. It looks like I can secure a couple of reconditioned 3208s (or 3208 turbos) for $11k (NZD) apiece. Will the 3208 bolt in where the 3160's used to be? How much of a major is this? Or should I get the 3160's reconditioned - again. Thanks in advance.
 
A little searching yielded some basic info. The 3160 was the predecessor of the 3208, and you might be lucky enough for 3208's to be a drop-in replacement.

But whether you should do that is not all that clear. The 3208 is commonly termed a "throwaway" engine, not rebuildable. So what exactly was done to "recondition" them? What was wrong with them before they were reconditioned?

On the other hand the 3160 has sleeves, and they can be reconditioned properly, assuming you can source the necessary parts. They are old engines, but if parts are available then that is the route I would take.
 
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They are rebuildable. You can bore the cylinders and use oversize pistons or bore them oversize and sleeve them back for standard bore size pistons.


A little searching yielded some basic info. The 3160 was the predecessor of the 3208, and you might be lucky enough for 3208's to be a drop-in replacement.

But whether you should do that is not all that clear. The 3208 is commonly termed a "throwaway" engine, not rebuildable. So what exactly was done to "recondition" them? What was wrong with them before they were reconditioned?

On the other hand the 3160 has sleeves, and they can be reconditioned properly, assuming you can source the necessary parts. They are old engines, but if parts are available then that is the route I would take.
 
They are rebuildable. You can bore the cylinders and use oversize pistons or bore them oversize and sleeve them back for standard bore size pistons.

Thanks for that info Sean. At least Drew now has some pointers as to questions he should be asking of the relevant people.
 
The engines are virtually identical. The 3160 was used in skool buses , where its easy inframe rebuild was no virtue as the skools had 90% of the replacement costs paid.

The waste collection folks loved them as they were efficient at no load, walking speed
Either engine is old but whichever is cheaper would be consideration.

Don't know if manifolds and exhaust parts will swop, but the dealer will have a book....

If in doubt rebuild the 3160, BUT at 4500 hours unless it was run hard & heavy 2,000RPM + a lot there should be no need to rebuild it.

Many older GB are displacement boats , so it should not have been flogged.
 
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Are the 3160s actually in need of a rebuild, or are you just thinking about it because they've got 4500 hours on them? If they still check out healthy, I'd just run them until they start to show wear issues.
 
4500 hours isnt a lot of hour IF the motors were well cared for. Of course, once you get an accepted price on the vessel, you will want to do an "engine survey". This will tell you what condition the motors are in and IF you actually have to rebuild them at all. IF you do have to rebuild them, then you can go back to the seller and ask for a price reduction because the motors are shot.
 
The OP noted that the 3160s are at 4500 hours "since the last rebuild," which may not equate to "since new." Still, these may be perfectly serviceable engines for years to come. Taras is right - an engine survey with oil analysis and all the rest will tell the tale.
 
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3208s are most definitely rebuildable. And, very commonly rebuilt.

But, what is wrong with the 3160s? How do they run?
 
I would like to know what the definition of rebuild means. I have 4600 hours on my 35 year old engines. I'm thinking of a refresh. That would be going through all the heat exchangers, all new soft goods, rebuilding the high pressure pumps and replacing the circulation pump. I would also have the heads inspected and rebuilt if there was any doubt. My engines do not currently need any of this and as long as I operate in the PNW I see no reason to fix what isn't broken. I am however, contemplating running the boat to La Paz and this is why I might consider investing this money. If you were to ask me I'm guessing my engines easily have 6,000 more hours in them. I'm not sure if they have another 35 years or just 15 years in them. Only time will tell for sure.
 
Don't know if they need a rebuild - I figured 4500 hours was old! I've been in touch with both previous owners - going back ten years - I can't imagine they've been flogged...
 
I think of rebuilding the block and head as replacing all of the valves, seals, gaskets, bearings, rings, literally, plugs, and reconditioning or replacing the crank and pistons (as needed), honing or boring and/or sleeving the cylinders as needed.

If remanufactured, I think of the above done by an authorized affiliate of the manufacturer using only parts from the manufacturer and I'd also like to think the block is magnafluxed and run on a dyno.

I think of either of the above comiwarranty. Significant warranty, the 1st from the builder and the 2nd backed by the manufacturer..

I think of an engine as being updated or maintained when the things around the block are addressed. Or, I might use a qualified phrase, sucubas exhaust overhaul, or fuel system overhaul, or cooling system overhaul, or raw water loop overhaul, etc.

YMMV
 
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