Official Caterpillar3116/3126 Thread

Caterpillar 3100 series engines are load sensitive at low rpms, and, above 2400 rpms which gets them into overloaded territory, if you run them more than 8% of the time above 2400 rpm.

Cats love to be worked and that means loaded enough to hear the turbos producing some boost and generating enough power to build some heat in the coolant. If you just idle them along, like running them below 1100-1200 rpm, you create a sooting condition and your oil samples will tell on you.

On my 450DA, 3116/350hp Cats, getting enough speed to get the hull to try to plane begins to load up the engines and was at about 1350 - 1400 rpm…..probably lower on lighter hulls like the 370/380, 400/410's. My engines were really happy at 1750-1900 rpm and they were also extremely efficient at that power setting.

Where you choose to run tends to be a compromise of how rough the seas make the ride and what rpms are best for the engine your wallet efficiency.
 
Thanks guys, so far we’re 70% tab, 2110 rpm, 19mph SOG, 15psi of boost, 650* exhaust temp. And my beer hasn’t spilled :)

typical Great Lakes windy day. 15kt north wind so we’re in 1-3’ at 2-3s on the port front quarter

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Fyi, quick video I did for those who want to set up coolers and heat exchange flushing on their own, in this case for one and three quarter inch inside diameter, one and a half inch and 1 1/4.

 
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Looking for thoughts regarding resale value.
The port engine is a CAT 3116 remanufactured engine with 108 hours on it.
The starboard engine is the original CAT 3116 with 1103 hours.
Both engines had oil analyses that came back all green check marks.

I've pulled the starboard engine to clean up corrosion on parts, get a transmission leak fixed and replace the engine mounts, etc, etc.
The question I have is, does it matter much in resale in 5-10 years, if there is over 1000 hours difference between the port and starboard diesel engines? Would it increase the resale if I bought a refurbished starboard engine for under $20K, bringing the hours close to each other?
I'm planning on replacing all the accessories, hoses, tubes, etc on the starboard engine.
Figured I'd ask while I have it out anyway.
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  • 20220510 Port Engine Oil analysis.pdf
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  • 20220510 Starboard Engine Oil analysis.pdf
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For me as a buyer all else equal, including the price, two identical boats sitting next to each other, yours and one with two remanufactured engines, I would lean towards the latter, but not by much though.

I think it depends on who your buyer is though. For me, being new to diesels with this boat, if I saw one manufactured one with 1,000 hours it would raise red flags to me. What happened to the original engine and could that happen to the other engine as well kind of thoughts. I was newer to Diesel's then though, I feel more confident with them now but would still have similar thoughts. Not enough as the owner to make me spend $20,000 though to help a prospective buyer feel better.

When I was in the market for my current boat I saw some with one refurbished engine, and I always ask myself what was the story. And did the owner cut corners by not taking care of the other engine. Most of the time it was a saltwater intrusion issue. Same when I saw one where they replaced the risers and manifolds, gas engine, in one engine and not the other.

My 1995 330DA had remanufactured long blocks, 1 hour on each, with a 12-month warranty, installed by the previous owner. That definitely helped my buying decision.

Good conversation for a broker you trust though.
 
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SCFoster said:
Looking for thoughts regarding resale value.
The port engine is a CAT 3116 remanufactured engine with 108 hours on it.
The starboard engine is the original CAT 3116 with 1103 hours.
Both engines had oil analyses that came back all green check marks.

I've pulled the starboard engine to clean up corrosion on parts, get a transmission leak fixed and replace the engine mounts, etc, etc.
The question I have is, does it matter much in resale in 5-10 years, if there is over 1000 hours difference between the port and starboard diesel engines? Would it increase the resale if I bought a refurbished starboard engine for under $20K, bringing the hours close to each other?
I'm planning on replacing all the accessories, hoses, tubes, etc on the starboard engine.
Figured I'd ask while I have it out anyway.
View attachment 132200
Click to expand...

you're saying you plan on keeping it 5-10 years? Unless you stand to benefit from the reman or it otherwise makes you more confident in the boat no way I’d spend 20k to reman it just because it’s out. Change the soft stuff, fix the leaks, paint everything nice and send it!
 
In the diesel world, a 1,000 hours is the break-in period. Anyone with any knowledge of diesels will not bat an eye at the difference...
 
4000 hrs on my engines. The juice isn’t worth the squeeze replacing a perfect engine. However, if you do, look me up. I wouldn’t pass up a reasonably priced spare.
 
That was my thinking, but figured I'd run it by the members. Thanks for the comments.
Since I had to replace both shaft seals and the yard I'm in is very accommodating for DIY, I'm going to pull the port engine as well, replacing both sets of engine mounts. Going to clean, prime and paint the engine bay, replacing all of the wear items. Will drop the P brackets, replace the cutless bearings and reseal everything. Any through hull fitting below the water line are going to get removed, serviced/replaced and re-bedded. All hoses to be replaced.
Do have a question about the diesel fuel tanks. Pretty sure they're aluminum. Was planning on getting a diesel sample analysis done. I don't see any inspection ports on them. Anything I should do with them while I have access? They look to be in good shape.
 
The starboard tank on mine was replaced by the PO, small leak in a welded seam. Sharing as FYI, I don't know if this is a known issue or not.
 
SCFoster said:
…
Do have a question about the diesel fuel tanks. Pretty sure they're aluminum. Was planning on getting a diesel sample analysis done. I don't see any inspection ports on them. Anything I should do with them while I have access? They look to be in good shape.
Click to expand...
They look good until they fail. I replaced the port tank. Had to cut it out after removing the engine.
 
Hello again. My first of many mundane questions now that I have full possession of the boat.

My overhead lights are not illuminating on the radar arch. Seems like all other cockpit and salon lights work fine.

What I am trying to figure out is which switch should control those lights. My best guess is the cockpit lights switch at the back of the cockpit. And if that is the correct switch, any idea why those lights won't come on?
 
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