CAT 3208 failure - how to prevent next time

[wgc851]

3208T's are still used in some SAR boats in the UK at 285hp and have a very good reputation for reliability.
Being SAR they run from cold to WOT and take a lot stick but on the other hand they are rigorously maintained and have regular blood tests.
They burn oil and used to eat head gaskets which was put down to a disagreement between the coolant and the head gasket but other than that they are ok.
I've no experience of the higher output variants but as plenty of others have said, might not be ideal for the application
And if they don't start on the first flick of the key then something isn't right!

 

[Slider70]

I ran a 3208 NA, 210hp, for years in my commercial troller. It also ran a very large hydraulic pump for my freezer. It ran 24/7 during the fishing season only stopping to make my oil and belt checks each day. I was religious in my servicing to the point of being laughed at by some other commercial fishermen.

But, it paid off as I had close to 20K hours when I had it rebuilt. The rebuild included boring out the engine installing over size pistons with one more ring than the original Cat ones. These were after market not Cat parts. Made the engine even sweeter as almost zero oil burn even running slow all night long driving the freezer. Along with very little smoke in morning run out to fishing grounds.

Before these different piston and extra ring the smoke was extensive after a slobbering night running the freezer. My rebuilder claimed Cat screwed up with the original piston design by not including the extra ring? This guy owned a Caterpillar service outfit which specialized in rebuilding Cats so should know Cat engines.

My only complaint about the engine was the number of belts (7) I had to run off it to drive all my other gear. The hydraulic pump was direct drive off the front of the engine. Other guys ran turbo units up to the 425hp but I never saw the sense to the extra horse power and extra trouble turbos can be especially as we were all running displacement boats that really didn't need the extra horsepower.

As stated earlier the easiest engine to start I've ever owned. If it didn't start instantly something was seriously wrong. Never had that problem in the 14 of to years I ran it.

 

[BrianG]

As stated earlier the easiest engine to start I've ever owned. If it didn't start instantly something was seriously wrong. Never had that problem in the 14 of to years I ran it.

Reminded of a 6v53 Detroit I had once upon a time. Great eng.

 

[danderer]

The GB 42 in later years ... would go much faster than it was designed for, threw a wake like a destroyer

Boy, that is the truth. 20 years later I still remember taking a wake from one running at speed. A bloody tsunami.

 

[Steve DAntonio]

I've had and worked on these engines. A few remarks on several comments above:
- 3208 are non-sleeved. They actually were called throw away engines. However when maintained they last very long.
- Highest rating is 450hp. Anything above the 375s I would think twice about.
- In the 425/435 series they had a design fault. There wasn't a drain in the aftercooler. As the AC is on top, the condensation dripped on the middle cilinders and corroded at least the valves. There was a CAT program to solve this afterwards but not all have done this. Be aware.
- The fuel pump had the tendency to leak fuel along the regulator shaft seal and fill the V on the engine block. Replacing this $3 part is a real PITA on the AC models as you have to remove everything...in what is typically a cramped installation.
- Be very sure the engines reach their rated WOT. Don't be fooled by brokers that say 100 oor 200 lower is also OK. IT IS NOT!
- Some models have an exhaust limiter valve to reduce startup smoke. If present research it is operating correctly as it can really damage the engine if it's not operating correctly for a longer time. Personally I would remove this and live with the (white) startup smoke.

Lots of luck!

Agreed, and any mechanical survey on these (and all inboard diesels) should include, among other things, crankcase and exhaust back pressure testing, as well as oil/coolant analysis. If the engine fails to make WOT, but the exhaust system is internally restricted from a failure (as a result of a past overheat) or installation fault, then it will rob rpm. Adjusting the prop to "correct" this is simply masking the problem. The crankcase pressure test will ID cylinder/ring issues, and the coolant/oil analysis may identify a head gasket issue. All pretty cheap tests in the scheme of things.

More on engine surveys here https://stevedmarineconsulting.com/the-art-of-the-engine-survey/

 

[mbdana]

Third Reef

When we bought our 36' GB, 3208 NA in 2018 it had 7200 hours. Although the boat was pristine in every way, prospective buyers were afraid about the hours. I called the the local CAT dealer and when described to them their response was "buy it". I also called the CAT expert, John Pride and he said the exact same thing.

He said a 3208NA is a forever engine with proper maintenance explaining all the lobster boats in our area with 20- 30- 50k hours on their engines. Some of their engine are TAs also, they just maintain them.

On the GB, at least the earlier ones, they are displacement hulls and will only go hull speed pretty much so my 220up 3208NA will push our boat as fast as a twin or a turbo so in my case and probably yours simple or less is more is better.

I would confer with someone like John Pride Inc Bowdoin Maine. johnprideinc@yahoo.com to learn about how to keep your engines up to par for life and to evaluate your current situation.

So there are no doubts in my mind, John Pride maintaines our CAT because that is the one most expensive component on our boat.

Best of luck.

Mike Dana
Third Reef
36' GB Heritage Classic
Potts Harbor Maine
207-833-5080

 

[Pat T]

Great thread! An update - the boat , a 2001 GB 42 surveyed well. Hit WOT , boost good, oil analysis good. Yes a few items need attention . Hope to work out few details yet. Every used boat is a compromise and we loved the GB 42. I did not want an 80's boat though and it was very hard to find a NA in later years. So when we saw this extremely clean ( we have searched over 1 year) with washer/dryer, bow thruster, newer propane over/stove, SS handrails ( a little less maintenance), and rebuilt long block CATS at < 350 hours! we decided to take a look. We will take the boat from northeast to Lake Michigan so fresh water may help a bit with maintenance. Since it is a really fresh rebuild I will get to care for it correctly and extend longevity- especially the AC's . I will not run it too lightly and certainly not too hard. Much to learn if this deal goes through.

 

[ghost]

I have not actually tried it yet, but I’m pretty sure if I suddenly yelled at my 210NA in Ernest, they would start right up from being startled.

Ran out of diesel once and after switching tanks, it was pretty bumpy, so I just turned the key and they self bled themselves. Ran a little rough for a few minutes, but didn’t have to bleed them in the chop.

 

[FF]

"The maker must have installed after coolers just for fun."

NO, they were installed to make a 200 HP ish engine be able to have a 400+ HP sticker stuck on the boost sales.

Engine longevity was not a concern , engine sales were.

 

[C lectric]

If you go for the boat MAKE ABSOLUTELY SURE to get the props adjusted/repitched so the engines make their RATED rpm plus another 100 or 2900 as already mentioned.

Just +1ing.

 

[FF]

"If you go for the boat MAKE ABSOLUTELY SURE to get the props adjusted/repitched so the engines make their RATED rpm plus another 100 or 2900 as already mentioned."


A reasonable plan B would be to run once to WOT , note the RPM and pull back 300 as your max usable RPM . Cruisinfg RPM may be slower , no black smoke should be seen at 300RPM down or at cruise.

 

[rslifkin]

"If you go for the boat MAKE ABSOLUTELY SURE to get the props adjusted/repitched so the engines make their RATED rpm plus another 100 or 2900 as already mentioned."


A reasonable plan B would be to run once to WOT , note the RPM and pull back 300 as your max usable RPM . Cruisinfg RPM may be slower , no black smoke should be seen at 300RPM down or at cruise.

In a GB with 400+ hp engines, that's probably not the greatest idea. You'd end up moving very fast at idle if significantly overpropped, plus you'd lose the ability to run fast with the big engines. With that much power, even propped correctly, a below hull speed "slow cruise" should already be at pretty low RPM.

 

[Steve DAntonio]

25-50 over rated WOT RPM is a typical goal, it ensures the engines can't be over-loaded if they are ever run at WOT, and it provides some cushion for weight being added to the boat. That sea trial for WOT should occur with a full load, full fuel, full gear, full water. 100 over won't hurt, it simply means you are underloaded to a greater and probably unnecessary degree. I've never seen an engine manufacturer ding a boat builder at commissioning for making over rated RPM, underloading. Under-revving, i.e. over-loading, on the other hand is forbidden.

More on WOT here https://www.proboat.com/2010/09/wide-open-throttle/

 

[DennisB1]

A question on after coolers on cat 3208 being bypassed: How did you by-pass? Are they still in place and the water loop coupled. I have two 3208TA 375 hp. I never use the rate power requiring the after cooler. Typically we run between 1300 to 1500 which is a 8.5 to 10 knot cruise with a clean bottom about 6 to 7 gal/hr total both engines. I have been thinking about by-pass as I have hear some leakage stories wiping out engines. I have had my AC out, cleaned and tested. They appear to be a robust design and I believe the tubing is a copper nickel composition. I also flush the engines with fresh water when leaving the boat no operable which lessens the corrosion issue.

 

[yarradeen]

How to prevent? Monitoring long term trends, I have been working on a monitoring project for a while now. Currently running on a mini computer (raspberry pi). every 15 seconds it stores temps of sensors located around the engine. This data is stored in a database. Once in the database there is long term data and you can spot issues before them become major. I then display them as a webpage accessible from any device with internet access either onboard or remotely. Currently I manually average and graph the long term data in excel but am building to towards automatic alarming based on anomalous behaviour. When I get time.

 

[FF]

"In a GB with 400+ hp engines, that's probably not the greatest idea."


The 300 RPM down concept is not for selecting or installing a cruising prop, just to operate the boat with no harm till the owner decides how he will prop and cruise the boat. A get home for a new purchase.

 

[rslifkin]

"In a GB with 400+ hp engines, that's probably not the greatest idea."


The 300 RPM down concept is not for selecting or installing a cruising prop, just to operate the boat with no harm till the owner decides how he will prop and cruise the boat. A get home for a new purchase.

Oh yeah, in that case, 100% agreed.

 

[ghostrider454]

Check out https://www.sbmar.com/

They mostly do Cummins but there are very good articles/advice by Tony Athens on what to look for in marine exhaust (plus other excellent articles not specific to Cummins). Using Tony's knowledge should give you a yardstick to evaluate your installation. The basic naturally aspirated 3208s are lifetime engines but by doubling the horsepower their longevity suffered. Some Cat blocks were not rebuildable but as I'm attached to a Cummins now, I have no idea which.
Check out Tony's stuff.

We used to have DD671 and then upgraded (we thought) to 3208 - loved anything naturally aspirated. When CAT decided to go turbo thus boosting the hp out of the same size engine, we went to 855 Cummins (now 8.3L). Red tops are indestructible. Can't say the same for 3208 t/a's. Plus they are noisy and don't get me started on the cost of ownership. I know of a guy who just bought an aluminum sportcruiser that had 3208 T/A's. I say had, because a month after purchasing - he had to repower it. He found a pair of remanned red tops and now he's very happy.