zenderV8

https://mbworld.org/forums/s-class-w...l-barrels.html


Indeed, scoring marks does occur even in the factory, but the real issue arises when the piston rings exceed their wear limits and malfunction. In such instances, since the engine must be removed, it would be logical to rebuild it with superior racing components.

crconsulting

Appreciate this information 👍
This eBay engine was posted in another thread so I figure I’d post it here so we can get possibly understand just when and if these sleeved M278’s were produced.
Of course as the old saying goes, if there aren’t pictures, it didn’t happen 😀
I’d love to have someone post a picture or link a video with these 2015+ engines with sleeves. I didn’t find one in this thread.

To preface this,
Have a friend who contacted me about trying to help them find an M278 block for their project….
He’s just about to get his block sleeved instead. We have yet to find any M278’s with cast iron liners.
I look forward to anyone who can post a picture of these cast iron sleeved blocks. I’d love to see one in the flesh. So far this is Vaporware.
I have also gone to look at several (4) engine cores locally 2016+ none were sleeved, but this the eBay engine that was posted in another thread…

It is Identified as a 2017 M278.
It is numbered 30 316114 so should fall in the cast iron sleeved range.

eBay 2017 M278 Engine Block

You can CLEARLY see from the pictures this block is NOT sleeved (no cast iron liners)

So the question is, does anyone have any pictures of these sleeved blocks from Mercedes?

Thoughts?



Here is the engine number from listing:



I think we can all see this eBay engine block is aluminum all the way thru i.e. no cast iron liners/sleeves even though according to serial number it should.




No way this is Sleeved…




The scratch on cyl 4 also shows aluminum all the way thru, no cast iron.

arsupisemnet

I am kind of tired of kicking dead horse, people don't take an advice when universe gives them a gift. Attached photo is a original MB M278 block with cast iron barrels, which i have in my possession. I don't know about date it was manufactured but it gives you an idea how it suppose to look like. It is under bunch of other things in my garage so i don't really want to move things around just to look at the date. Same look as the one i showed on that eBay listing. I am not affiliated with seller, just gave an advice

arsupisemnet

And this is a original MB M278 block with Silitec barrels. It has no metal transition line on top of the barrels because it is similar alloys.

arsupisemnet

If some one is smart enough he will grab that short block of eBay. All it needs is a set of bearings, aftermarket rings, and good wash in industrial parts washer. May be one pass of flex hone to remove glaze and prep for new ring set.

arsupisemnet

Now since i am the one who machine blocks of any kind on daily basis in the pictures with cast iron barrels or cast iron aftermarket sleeves you would see honing marks which is not present in Silitec sleeves unless some idoits got their hands to it. There is no regular honing procedures on Silitec barrels.

crconsulting

Thanks so much for taking the time to post a picture 👍. We’re all super busy and always appreciate when someone takes the time to add something positive to the discussion.
That’s exactly what I was looking for. Though it can be tough sometimes to see details in some web pic. From your newest picture, they appear to be either “cast in” liners, or some other additive machining process similar to mirror bore technology using the HELLER CBC 200’s at the Stuttgart plant. Probably why you can’t see a separation between sleeve and block on the eBay engine block. They don’t appear to be pressed in. I think @chassis (and I) expected to see press in liners….

So that clears up a few things. Funny you mentioned the honing, though sometimes tough to judge from pictures, I agree, my initial thought was someone tried to hone it, as surface finish is atypical than one would expect to see on Nanoslide/Silitec bores but would make sense since they used different rings for the iron bores.

I’m not sure if the production number switchover is accurate, something may have gotten lost in translation. But will pay closer attention to engine numbers to verify.



We appreciate it 👍. I did pass the listing on since these USABLE 15+ later engine cores are somewhat difficult to find at this stage…..

btw retired now but worked as an MB tech, later moved to the machine tool industry 35 years total. Have spent entirely too much time behind a CK -10 so have a fairly good grasp on this subject 😀


Thx and Good Luck!

Œuvre

I'm not sure whether this has been discussed in here, but Tasos Moschatos' theory about a contributing factor to the M278 cylinder scoring issue (i.e., https://youtu.be/unYOuglDIcM?si=uR8iJnZejDefx9Y8&t=90) and a possible preventative measure(i.e., https://youtu.be/unYOuglDIcM?si=4Dut7z0_VXcW7o7z&t=45) is something that I have taken up with my own shop's techs in recent years...

arsupisemnet

It been discussed thousand times, there is no preventive measure for it. Once factory coating is gone it is ticking bomb. Only way to prevent is to swap pistons every 50k miles with stock tune, or 30k with high boost. Or get pistons coated with something like that https://industrialhardcarbon.com/coa...e-crn-coating/
Most of the people doing this kind of videos just looking for audience to believe their crap

diesel_dan

Why are not more folks talking about unplugging the oil pump DUMP valve? It makes so much sense for owners to do and there really is no downside (well, maybe a tiny bit of fuel mileage???). The scoring is a lack of Oiling issue, not a coating issue as some would have you believe...

CaliBenzDriver

yes, very true!
The oil pump solenoid shifts the pump volume from low to normal volume. It does not dump or bleed out pressure. It physically switches between small pump vs. normal pump.

That feature detunes the engine and limits pistons heat removal. The VVT positioning directly benefits from stable oil viscosity.

Driving around on low pressure with low viscosity leads to excessive oil consumption from stuck rings.

arsupisemnet

Once again "professional" advices do more harm.
"Once solenoid activated it minimize oil pressure, without electricity pump pumping at 100 percent"
That is not "dump valve". That is control valve for housing geometry

diesel_dan

Okay, so calling it a "dump" valve is too extreme then... When the solenoid is energized by the PCM the oil pressure is reduced and at the reduced pressure there is not enough oil pressure to overcome the check valve springs in the piston squirters, so no piston cooling or added cylinder lubrication at lower RPM, and inconsistent pressure to the VVT system. Does that sound about right? I have about a thousand miles with mine unplugged and it runs like a scalded ape - might be my imagination, but it seems a bit more snappy with the Go pedal...

CaliBenzDriver

yes Dan, that is 100%

scaleded ape LOL

accelerator response: yes definitely!
It cancels the factory lag.

To further cancel extreme piston heat you can gradually switch to better oil viscosity as the cylinder lost compression are restored.