Rebuilding In Place

Since the thread on injectors, I have been thinking about compression, or lack thereof and what direction I should go (if any) to reduce the smoke at start up and low temp. I have been researching compression testing equipment and plan on, at first, doing a comprehensive test to see what kind of compression I have. If compression is low then the most likely and least costly remedy is a re-build. I like the Perkins and would not want to re-power and since they are a "sleeved" motorit seems to make the most sense. The re-build kits from TAD are pretty reasonable. I have re-built gas motors and don't feel that this is beyond my capabilities. I have never done an "in place" rebuild though. Obviolsy this would be the most convenient method, but wonder if possible. The obvious challenge is dealing with the crank and removing the piston rods. Has anyone done this? The other thought is to find another motor, re-build it, swap it out and then rebuild that one, swap it out and sell the last motor, or keep for spare. Any thoughts?
Thanks

If you need help, Phil Everett Diesel, is my diesel mechanic - 360-789-8250, and he will work with you. If it was me, I would strip the engine down, have him due the rebuild the engine and I would re install the bolts on stuff.

I would not swap out the engine.

Max Simmons said:

Since the thread on injectors, I have been thinking about compression, or lack thereof and what direction I should go (if any) to reduce the smoke at start up and low temp. Any thoughts?

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Several ... how much does it smoke and for how long?

Does the engine start easily when cold?

Is this a new phenomenon or has it been going on for some time?

Are you burning an excessive amount of lube oil?

Is the smoke threatening your lifestyle or ability to use the boat as you wish?

Max I would say it will depend a lot on how much room you have.

I did the top end of my 3208 Cat but I have pretty good access. Still a lot of crawling around to get to things. The only issue is if you need to bore the cylinders before resleeving. It cold be done with a boring tool and a drill. Just to clean the cylinders up. Would you have room to press the old sleeves out? Or how did you intend to remove them.

Sd

RickB said:

Several ... how much does it smoke and for how long?

Does the engine start easily when cold?

Is this a new phenomenon or has it been going on for some time?

Are you burning an excessive amount of lube oil?

Is the smoke threatening your lifestyle or ability to use the boat as you wish?

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Smokes heavily when cold, clears up around 140 deg.
Block heaters in the colder months reduce it

I do have to crank 5-8 seconds to get it to fire when cold. When using heaters, usually start in seconds after hitting button.

Been happening since I bought the boat 6 years ago. Isn't any worse, just getting less tolerant of it.

Starboard engine doesn't burn any oil. Port a small amount. I add maybe 1/2 qt between changes

No lifestyle threat. I do switch on the block heaters in the summer when firing up in a crowded moorage to minimize smoke.

I'm wondering if some of it might be just the nature of the motors? Without glow plugs, my 120's smoke the place up pretty good until warm. Nothing visible once warm, or while running. No significant oil use.

Wolverine heaters on the bottom of the pan may help too. Unless there is a really bad engine noise somewere and since you're not burning an unusual amount of oil, hard to see where pistons, rings and cylinder walls need to be changed. Maybe a valve guide or two has worn, but it can't be too bad since your oil loss is very low. Normally low compression is associated with high oil consumption.

What type of oil are you using? What year and engine model do you have?

Our experience is the same as Somesailor's. If an FL120 doesn't fart out some blue smoke on startup there's something wrong with it. On our boat the smoke almost immediately begins reducing in volume and is virtually gone within a few minutes. It's caused by lube oil in the valve train seeping down past the valve guide seals into the cylinders where it sits until you start the engine again. It's pretty much the nature of the beast and our engines have done this--- and their behavior in this regard has been unchanged--- for the fourteen years we've owned the boat.

The other thing this generation of engine does is put unburned fuel into the water with the exhaust until the cylinder temperatures get up to where all the fuel being injected is burned. The unburned fuel is evidenced by a fair-sized sheen on the water behind the boat and this can look somewhat dramatic, particularly in cold weather. Of course oil and fuel in the water is like blood--- very little looks like a whole lot.

But this, too, is just the nature of the beast. A friend in the marine diesel manufacturing business told me that eliminating unburned fuel at startup (for environmental reasons) is one of the most challenging things an engine manufacturer has to do and I guess is one of the things electronic engine controls have made possible.

Overhauling our FL120s in an attempt to reduce the normal smoke at startup would, I think, result in spending a whole lot of money to accomplish pretty much nothing.

In the winter we keep a heater in the engine room that keeps the space at about 55 degrees so regardless of the temperature outside the engines start immediately and don't smoke or blow unburned fuel any more than they do in the summer.

Max Simmons said:

If compression is low then the most likely and least costly remedy is a re-build. I like the Perkins and would not want to re-power and since they are a "sleeved" motor it seems to make the most sense. The re-build kits from TAD are pretty reasonable. Any thoughts?
Thanks

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Are these 6.354's. They are notorious smokers, some from the get go. Lots of early Californians had trouble with the rings seating during break in with the 6.354's. Depends who you talk to what the cause was. The compression is only 17:1 and with bad valves this can drop off pretty fast. Lower injection pressure than a modern diesel doesn't help either.

They make hot starts for the intake manifold of the 6.354. Injects oil through a glowing hot coil, while engine is cranking, which is ignited and sucked into the cylinders. Engines start almost immediately, with no cranking in any weather. It's a pretty straight forward install, but does require some handyman drilling and tapping skills.

If you're not burning lube oil then not worth a rebuild, but check the compression. It could also be valves. If you have had any saltwater ingestion from leaky pipes over the air intake (this is common) it will be definitely valves. Saltwater eats up the valve seats.

Larry B

For most pleasure boaters the time for an "inframe" is when the compression becomes so low it wont start in 70 deg weather ,smokes when warmed to 180, or when the oil consumption bill becomes too high!

A "rebuild" requires engine removal as the block will be cleaned , the crank straightened and perhaps re ground and many other machine shop operations carried out.

An "inframe" is new cylinders , pistons and crank and rod bearings.

The engine must usually be lifted to get to the crank, but not removed for the procedure.

True industrial engines will get 2 or 3 inframes before requiring removal for rebuild.

Skills even for an inframe are not found at the usual boat yard.

They would be better at R&R to install an engine going to the PRO rebuilder.

If you start a Perkins or Lehman and it isn't smoking........shut it down....it's out of oil.

OkSkipper said:

If you start a Perkins or Lehman and it isn't smoking........shut it down....it's out of oil.

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That's what they say about the DC-3's in Columbia.

The District of or that place in South Carolina?

I would guess the one south of Panama that probably still uses the C-47 to deliver cargo that is out of political favor, but makes so much cash for the politicos.

Agree that 6.354's can be smokers at light load and/or low coolant temps. I have one in my fishing boat. First, make sure you have a properly working thermostat that allows it to come up to 170 at moderate load. Then if it continues to remain cool check the compression. If low, you may just have glazed cylinders. It is not a big job to pull the head and hone cylinders with pistons in place. Finally, if temp won't come up at low power, and you have one of the older models without the manifold/heat exchanger in one; you can convert the manifold to freshwater cooling and get much faster warm-ups and better temps at light load. As a bonus, your manifold will then last as long as the block.

RickB said:

The District of or that place in South Carolina?

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Like Bogata, Cali, etc.