Cleaning the inside of a cylinder liner

I would say that liner break in and establishing a proper cylinder lubrication are so crucial and so constantly being tweaked as far as fuel composition, lube rates, break in procedures, etc. these days that introducing one more variable seems unwise. But as has been discussed I’m not really going on anything here so…

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As a former diesel engine mechanic, I have never rebuilt a large, slow speed diesel. EMD was the largest engine I ever dealt with. However, as far as cleaning the wax/ preservative from the inside of the liner…are you kidding me!!! I would get fired if I installed liners that were not completely cleaned before dropping them into the block. Plus, with all the concern of proper lube oil function, how will the wax affect the oil & the bearing surfaces & passageways as it flows through the engine? Maybe it will clog some small oil passages when the engine cools after shutdown, which will cause loss of oil circulation upon start up. As mentioned before, what about the oil scraper ring getting clogged up with wax?
Too many negative possibilities here to install liners without thoroughly cleaning them first, whatever amount of labor is involved.

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Low-speed diesel has a different lube oil setup.

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An EMD is a trunk type engine. So it makes sense to clean the inside of the liners before installation. I’m discussing a crosshead engine.

Not an issue as the oil in this part of the engine is burned up and drains down to a sludge tank.

Same as above, not an issue on a crosshead engine. Not to mention the fact that the LO pumps are off engine, driven by electric motors. The LO is always flowing unless the engine is taken down for maintenance. I also try to never allow the engine to cool down too much. (I use 70 C as a rule of thumb)

The engine is not equipped with oil scraper rings. On this particular engine the only special ring
it the top ring (CPR ring). The other three are normal compression rings.

Clean it. How do you know it’s only wax? I’ve seen all sorts of crap on the inside surface of a new liner, even when it comes in MAN’s special foil baggie. IMO, you’re going through all the trouble to change the liner out, might as well make sure you’re actually doing a good job of it. We usually clean it before we take it out of the rack. WD40 works well, so does diesel. Check to make sure you’ve gotten it all out of the lubricator grooves as well.

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Seems to me that if the OP spent as much time cleaning the new liner as he did discussing it here on the forum, he would have been done some time ago. If he is concerned about entering the liner, what will he do when he has to take wear readings?

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Seriously, just clean it already. Is there harm in not cleaning it, possibly, maybe. Is there harm in spending the time to clean it, none that i can see. Just clean it already and be done with it. Sleep better knowing that any lube oil or wear problems on that cylinder weren’t possibly caused by you leaving the wax on it during install.

The liner is behind me at this point. I was still interested in discussing whether anyone was aware/had done it with the inside still coated.

Use the MAN tool…

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How old is the engine? We’ve got a different version of that tool for our ME-C. Also, have you guys had MAN come with their VAK tool? They’re a pretty neat way to go as an in-between service option. It goes in through a scavenge port and on top of the piston. Then you roll the engine and it laser scans the liner as it travels up and down. You’ve usually gotta pull the indicator cocks in order for it to communicate wirelessly with a computer that downloads the data.

The engine is about 12 years old.

I’ve never seen the VAK tool, first time I’ve heard of it. Probably gives a better indication of any corrosive wear than the inside mic tool? Not to mention the fact you can probably measure all the cylinders in a few hours.

https://primeserv.man-es.com/marine-engines-and-systems/two-stroke/Technical-Service/CombustionSpaceCondition

Looks better than peering up through the scav ports with a inspection mirror.

The mic tool works pretty well, but it’s still just sampling a very small amount of the cylinder. I’m not sure that the VAK is leaps and bounds ahead, especially since it seems finicky. The biggest advantage of VAK is that it can do the whole liner and you don’t have to pull the cover to do it. You may be able to see corrosive wear, but you should also be picking that up during the cold corrosion and sweep tests.

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The VAK is nice but of course the one time I saw it, the next manual measurements a month later during a piston pull were grossly different, of course that unit was in bad shape and the liner could well have just passed a point of no return and started wearing very rapidly.

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I’d be more concerned with what happens when the liquefied wax sets up again, hopefully most of it is in the filter? overall, i’d probably end up doing a half ass job (getting the thickest stuff off) and getting some fire in there! Let us know if it lasts as long as it is suppose to.

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