Is the Cat 3208 a "throw away engine"? I think not.

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RickyD

RickyD

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May 4, 2018
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Since the venerable 3208 does not use cylinder sleeves I have some Cummins friends referring to it as throw away. Well, a recent review of the old owner's receipts and invoices shows that my starboard engine had a catastrophic injury and the cylinders were bored and sleeved to use the standard pistons, rings, rods, etc. The only odd note was to use a different part # for the head gaskets. Yes I knew it had been rebuilt when I bought her. It had about 100 hours on the onboard engine hour meter while the fly bridge meter reads total hours. Something like 1700 when I bought her. I just thought you'all might find that interesting.
 
The "throw away" term was often applied to diesels that weren't sleeved and couldn't be rebuilt in place or an unlimited number of times. That certainly doesn't mean they aren't rebuildable (once or twice) or that they're bad engines. For someone used to old Detroit, International, etc. iron a 3208 or Cummins B series would be a "throw away", but that's all relative and doesn't necessarily mean the non-sleeved engines are bad.
 
I believe 9N6275 is the part number for the genuine Caterpillar dry sleeve to remanufacture a 3208 block. They start out with a parent metal bore but if worn or damaged can be resleeved to original dimensions in a machine shop.
 
Island Cessna said:
I believe 9N6275 is the part number for the genuine Caterpillar dry sleeve to remanufacture a 3208 block. They start out with a parent metal bore but if worn or damaged can be resleeved to original dimensions in a machine shop.
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Good point, if you've reached the maximum overbore it's often possible to press in sleeves to save the block provided there's enough meat to bore it enough to sleeve back to the original dimensions.
 
I haven't seen any invoices for removal of the engine. I believe it was done in place. I have good overhead clearance and an able to stand upright in there as long as I tilt my head down.
 
rslifkin said:
The "throw away" term was often applied to diesels that weren't sleeved and couldn't be rebuilt in place or an unlimited number of times. That certainly doesn't mean they aren't rebuildable (once or twice) or that they're bad engines. For someone used to old Detroit, International, etc. iron a 3208 or Cummins B series would be a "throw away", but that's all relative and doesn't necessarily mean the non-sleeved engines are bad.
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Another problem adding to the "throw away" tag with these Cats ( I have one in my MS350) the cylinders are completely surrounded by water in the block. This makes the cylinders harder to mate with a new surfaced head when rebuilding. But an interesting story along these lines, I blew a water pump belt about 3 miles from the dock. With all that water in the block, I could idle for about 20 minutes before the engine temp alarm would go off. So at 1-2kts I was able to get to the dock by running idle for 20 minutes then at anchor for 20 minutes.
 
I think the throw away term came from ease of replacement . Back in the day we had a lot of equipment and trucks that used the 3208 non turbo engines. They kept original cat rebuilt engines on the shelf. We could buy a rebuild with a warranty cheaper than the parts and could have the rig back in service in less then a day.
 
RickyD said:
I haven't seen any invoices for removal of the engine. I believe it was done in place. I have good overhead clearance and an able to stand upright in there as long as I tilt my head down.
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Would love to hear if you are able to confirm the rebuild in place. I have twin 3208NA.
 
Whether or not you can rebuild in place depends on what's needed. If it's a light rebuild you could potentially lift the engine enough to do bearings, hone the cylinders, new rings, etc. But if it's time to bore and install oversize pistons, you're going to need to get the engine to a machine shop.

Keep in mind, you can always strip the engine down on the boat and bring it out in pieces, then do some of the reassembly after the parts are brought back to the boat (such as putting heads on the block). That will make the parts lighter and smaller if the ability to get them off the boat is limited.
 
Generally rebuild in place is not possible. The reboring of a cylinder is just not what most places are capable of. The exception is where it is determined a minor honing may suffice.

There used to be a famous rebuild place in Crisfield, Maryland that could arrange a takeout and replace/rebuild for peanuts. Not sure if still in operation. T&S Marine was the place.

It was because of this kind of operation I bought a sportfish liveaboard back in the 1990s with 3208TAs..... a great engine for the application ( though there are obvious improvements these days).
 
rslifkin said:
Whether or not you can rebuild in place depends on what's needed. If it's a light rebuild you could potentially lift the engine enough to do bearings, hone the cylinders, new rings, etc. But if it's time to bore and install oversize pistons, you're going to need to get the engine to a machine shop.

Keep in mind, you can always strip the engine down on the boat and bring it out in pieces, then do some of the reassembly after the parts are brought back to the boat (such as putting heads on the block). That will make the parts lighter and smaller if the ability to get them off the boat is limited.
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I was curious about the boring and re -sleeving for standard piston/rings.
 
Mac2 said:
I was curious about the boring and re -sleeving for standard piston/rings.
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I can't imagine that being done outside of a machine shop. But generally if there's enough meat on the cylinder walls to support an over-bore and there are oversize pistons available then that would be the route taken for the first rebuild. No need for sleeves if there's still enough meat in the cylinders and an over-bore and hone is less work than boring and sleeving. You'd only go for sleeves on the first rebuild if there's damage that an over-bore won't take care of.

It looks like there are at least 0.020" oversize pistons available for the 3208 and for some versions you can get 0.040" oversize pistons (which would allow cleaning up worse damage or support a second rebuild without needing to sleeve the block yet).
 
CharlieO. said:
T&S is still in business one of the Youtube channels I follow brought in a Cat for refurbishment.
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Back when I lived abord on the Chessie, and had the boat with 3208Ts, I could ger a replacement/rebuild for not much more than a new 200hp outboard.
 
psneeld said:
Back when I lived abord on the Chessie, and had the boat with 3208Ts, I could ger a replacement/rebuild for not much more than a new 200hp outboard.
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The thought of removing an engine makes my toes curl. Not so much the work, but tearing up my cherry wood floors.
 
Mac2 said:
The thought of removing an engine makes my toes curl. Not so much the work, but tearing up my cherry wood floors.
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Time to start measuring to see if you could break the engine down into pieces that will fit through available openings. Otherwise, it might be possible to modify the floor to have a large hatch over each engine to allow them to be lifted out.
 
rslifkin said:
Time to start measuring to see if you could break the engine down into pieces that will fit through available openings. Otherwise, it might be possible to modify the floor to have a large hatch over each engine to allow them to be lifted out.
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I have the engine patch on the floor, but custom cabinetry partially covers them.
 
Mac2 said:
The thought of removing an engine makes my toes curl. Not so much the work, but tearing up my cherry wood floors.
Click to expand...
Why I like boats with workboat roots over yachtie lookers...but an old habit as that is all I ever was able to afford. Luckily, many older boats were a bit easier to work on.
 
Yikes!!! I always assume the engine or a tank will need to go out or in at some point.
 
rslifkin said:
Good point, if you've reached the maximum overbore it's often possible to press in sleeves to save the block provided there's enough meat to bore it enough to sleeve back to the original dimensions.
Click to expand...
The difference in the head gaskets is the gasket for the bored or sleeved engine has a wider sealing area around the bore to compensate for the lost material. "Throw away" was a design designation not an actual description of the motor which as many have said is rebuildable as long as you have enough material left in the block.
 
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