3208 Cat Blow back through intake

[antioch01]

Do you think the straight weight oil would be better ? Why ? I have only used 15-40 in everything except our bus,, 8V92 Detroit. It takes straight 40 ONLY, NO EXCEPTIONS. I have heard many reasons why,, but curious about your recommendation.
I am pretty sure the new oil that is in them now is 15-40 Rotella.

 

[Ski in NC]

Lots run straight 30 on 3208's with good results. But most run 15-40. I don't think it makes any difference, run what you like. 15-40 more popular as it is easier to find.

Valve spec is 0.015" intake, but exhaust is 0.025".

 

[antioch01]

You are right about straight 40 hard to find, I have to order cases from my wholesaler. Not many 2 stroke diesels left on the road.
Thanks for the heads up on the exhaust valve setting. It is in the book, but I had not looked that far, was more concerned with the intake issue.

 

[FF]

"You are right about straight 40 hard to find"

,My local wallmart has Shell rotella which in 40 wt has the rating CFII, 2 stroke Detroits require.

"Do you think the straight weight oil would be better ? Why ?"

Yes, I always prefer straight oil if the Mfg and temperatures allow.

The multigrade oil has the equivelant of flour mixed in to thicken the oil when its warm.

I prefer oil in my oil, although 15-20% of the oil is other additives anyway.

Anti foaming, anti scuffing, acid eaters, and way more.

The changes in engine oil over the years is mostly improving additive packages ( to eat EGR exhaust for the air police).

As these have no use in an older engine why take out lubrication for them?

 

[Bruce B]

"You are right about straight 40 hard to find"

,My local wallmart has Shell rotella which in 40 wt has the required CF!! 2 stroke Detroits require.

"Do you think the straight weight oil would be better ? Why ?"

Yes I always prefer straight oil if the Mfg allows.

The mult igrade oil has the equivelant of flour mixed in to thicken the oil.

I prefer oil in my oil, although 15-20% of the oil is other stuff anyway.

Anti foaming, anti scuffing, acid eaters, and way more.

My understanding is that although once upon a time viscosity indexers, especially in the old 10w-40 oils, occupied a substantial % of an oils volume, this is no longer the case.
Better life through chemistry?
Of course synthetic oils have none of these issues anyway.
Not sure if synthetics are specified for the Cat engine though...
Bruce

 

[bayview]

some of that stuff in new oil is intended to reduce scuffing on cam. Even older engines can use that but in the final analysis lube failures seem very scarce regardless of oil used.

 

[Ski in NC]

3208 375 uses roller cam followers, scuffing no issue.

 

[antioch01]

I know Detroit is very, very adamant about only using straight 40 diesel quality oil in their two strokes, and so far I have not seen them budge on the issue, even with the new multi viscosity oils, so that is what I maintain in it.
This boat has 15-40 new oil now,, not sure changing to a single viscosity is a good idea now,, since you never get all the old oil out. That is probably another whole discussion on mixing oils.
The roller cam sounds very good,,, was not aware of that, and that is an area I would not be able to check until too late.
I use a roller in my B/B blower boat.

 

[BerettaRacer]

What oil do your transmissions and generator use?
It's a lot easier to buy/carry spare of one particular oil for all your equipment than various oils.
When I was fleet engineer for a major yacht builder I would meet with reps from the various manufactures and try to get them to agree to a standardized oil, get it in writing, and add it to the boats file for the future owners and engineers convenience. Did this for both lube oils and hydraulic oils, then built in storage tanks directly into the hull. Clean oil, waste oil, and hyd oil, sized in accordance with a complete service change capacity.

And right off the top of my head, my guess would be, as someone else mentioned, just a bit of surface corrosion preventing a good seal/seat, and MAY clear up with some use.

 

[antioch01]

3208's and gen have 15-40 Rotella,,,,, trans not sure. Will have to check with mechanic that did the oil changes and start-up.
I am leaning towards the consensus of taking the chance and running them.

 

[FF]

"I am leaning towards the consensus of taking the chance and running them."

Nothing to loose , worst case you eventually yank the heads and send them out.

And have a service come in and hone the cylinder walls , in place.

No big deal.

 

[sunchaser]

3208's and gen have 15-40 Rotella,,,,, trans not sure. Will have to check with mechanic that did the oil changes and start-up.
I am leaning towards the consensus of taking the chance and running them.

Consensus, no. Your desires, yes.

 

[antioch01]

Well, there is a lot to lose if I am wrong, and they require a major O/H,,,,, the amount I am willing to pay for the boat is contemplating being able to use the engines. Also, if the time required to repair takes too long then the dry time in a DIY yard also becomes expensive. I plan to use that time for a bottom job and get it back in the water.
I am trying to make an "educated decision" on the boat purchase, as well as trying to manage my desires vs realistic costs.

I am sure some of you are thinking, that idiot should just get it surveyed,,,,, but with the oils already replaced I think an oil analysis is useless for at least the next 20 to 50 hours. Which after that I would have one done by my wholesaler that provides that service free.
I am the type of guy that would rather read and investigate all issue possibilities and put my own hands and eyes on it. Since I am the one that would perform the repairs. No one else to blame if I miss something.
That is why this forum is so great,, different ideas and experiences that help a person think in many directions that one might not think of on his own.
All of the replies are greatly appreciated and carefully digested.

 

[FF]

"Well, there is a lot to lose if I am wrong, and they require a major O/H"

A major would be removing the engine , boiling it clean having the crank & cam line bored, the cylinders (this is a non sleved engine) bored oversize and new pistons wrist pins & rod bearings and cam bearings replaced.

The cam and crank would be straightened and bearing surfaces renewed.

With such a low time engine NONE of this should be required.for 10,000 hours.

Pulling the head should be all that might be needed is the engine time is that low.

Unless it was at one time sunk.

 

[antioch01]

That pretty much sums up my thoughts as to the differences in cost / time. And the indications and data available.

Now it is a matter of placing that bet, we will see here soon.

 

[River Cruiser]

If you're serious about this boat and the concern is condition of the Cat 3208. Call the local Caterpillar dealer and have them send out a field mechanic to run a diagnostic test on the engines, they may even have some history of anything done on them if work was performed by a Caterpillar dealer. You may consider the price very high but these guys know these engines, have the proper tools and equipment on their trucks to do it right. The cost will be well worth the peace of mind you'll have, otherwise it's a roll of the dice. How lucky are you feeling?

 

[The Other Gary]

The Elephant in the room is the fact that there is less than 100 hours on these engines.
The rings on a diesel at installation are rounded, tapered or both and can take up to 300 hours to properly wear to seat flat and achieve design compression.
Tony Athens had to remind me of this once.
During this time it is not unusual to see what may be considered to be excessive blowby.


These engines, lacking any other issues, are not fully broken in at this point.

 

[antioch01]

I have always trusted my instincts and gut feelings,,, in stocks and life in general. And in this case with a lot of appreciated input from this forum.
So far I have been very blessed.
I understand the piece of mind, but my experience with professionals has not always given me that and instead gave me the uncertainty of whether the job was done correctly.
As always there are exceptions but I have found them to be few.
I have taken the gamble and we will see if the offer is accepted.

 

[Ski in NC]

Before closing on the deal, post a vid with audio of the engine behavior you thought unusual.

 

[antioch01]

Too late,,,, already made the offer,,, if it is accepted I will post many vids,,,,,

 

[BruceK]

Too late,,,, already made the offer,,, if it is accepted I will post many vids,,,,,

You can still raise the issue arising from survey, so it is worth providing the requested vid, if/when you next get access to make it.

 

[Ski in NC]

Yep. An accepted offer and closing are different things. Prior to closing, issues found can be negotiated.

 

[antioch01]

You guys are right if this was a traditional deal,,,, it is not.
I am offering to purchase cash, as is, no broker,, that is the reason for no survey and my own diligence prior to making the offer.

 

[BruceK]

Paying cash for a boat with no broker involved does not of itself exclude usual hull and mechanical surveys, and instead limit the buyer to DIY checks.
Even if a seller declines to negotiate on any issues survey reveals, you usually have the option to withdraw from the deal if the boat is not as represented.
Your purchase agreement must exclude all those check and review entitlements. Let`s hope the boat is everything you want it to be.

 

[River Cruiser]

About 30 years ago I was thinking about getting a 2 ton cab and chassis to replace my f350 1 ton mechanic truck, the f350 was really overloaded with tools, welder, air compressor and crane. I ran across a f800 owned by a insurance company, it had been stolen with a lowboy trailer when both were new. The rig had set for over 10 years in a barn on a farm, may have had sporadic use. The rig had less than 2000 miles on the odometer, the 3208 engine started, ran and smoked like all the 3208 cats I ever seen in trucks and equipment. During my checking it out I pulled the dipstick and the oil was rust colored, I believe it had sat so long the cylinder walls dried out and rusted. When it was fired up the rings knocked the rust off and probably knocked the edge off the rings. I doubt the rings ever seated during the short amount of time it ran and probably never would, it did have way more blowback than I would expect, I decided to not even place a bid on it. Lack of use is detrimental to anything mechanical, I would much rather buy something that has been used and properly maintained. Good luck on your purchase.

 

[Martin J]

Agree with David, sounds like over tight valve clearence. Come across it before.

 

[antioch01]

Well, they did not accept the offer,, too much sentimental value. They plan to address many of the issues to get more out of it.

Thanks again for all the replies,,, much appreciated, Looking again.

 

[Irish Rambler]

The bottom line is.
Are you a hands on guy with the ability/time/wallet to rectify any problems ?
If the family just wants the estate cleared you could be staring a gift horse in the mouth.(smaller dent in the wallet).
I've started and run diesels that haven't run for 20 years with no problems.
Of course you will see a little puffing in the rocker cover, marine engines recirculate engine breathing back in via the rocker cover, (to prevent fumes in an enclosed space) if the engine didn't breathe it would blow up.
If the boats in the water take it for a spin, monitor temps and pressures and build up to WOT for 30 mins, that should clear any smoking and free off a sticking oil control ring before reducing revs gently and by the time you get back to port you'll have your answer.
Just remember that if a man made it, a man can repair it.

 

[antioch01]

Oh I am definitely a hands on type,, and planned to do all myself, except maybe pressure cleaning the bottom.
The main issue was no steering, so no water test. I made the offer anyway and figured all the issues in the price.
Just not quite enough cash to make it happen. I think the engines would have been alright like you say,,, lots of other issues,,,, all appliances, steering, some wiring issues, some interior leaks. Great bones though.
Still wanted it, and I think it would make a great boat,, just could not pay any more with all the $$ I figured it needed to make it nice.

 

[BruceK]

You might hear back yet. Any other buyer will have similar concerns.
Alternatively, you may have dodged a bullet.
See it as a learning experience, if nothing else.
In real estate, post mortems like this are called "peeing on the ashes".