5soko

Hey guys, didn't know where to post this information, as I have been getting many DM's and emails about it. And i didnt see a thread revolving around this information so i figured start it here for you guys to discuss.

As many of you may or may not know, Mercedes Benz M278 V8 engine used silitec cylinder barrels for many years. This is the Aluminum-silicone cylinder treatment.

As of March 16th 2015,

Engine number start : 2789xx 30 266191, Mercedes change over to cast iron cylinder barrels. Along with new pistons and rings of course to match.

M157 V8 unfortunately did not get the same treatment because of the low volume and near end of its production cycle, and used silitec liners to the end of its lifecycle.

Chevota

I didn't know that. Damn, I missed the iron by a few months... Something to keep in mind if I buy another one.

S-Prihadi

This silitec coating, is it the same as the twin wire arc NANO COATING MB describe ?

Find attached the WIS on the twin wire arc NANO coating

chassis

Is there a Mercedes-Benz source document you can share regarding the change to iron liners?

5soko

Hey, silitec and the nano liners are completely different.

5soko

You mean to tell me you dont believe me and my buddies from Germany haha! Yes, i attached the M278 WIS document in the first post giving some of the same info i described here. I will also attach the most current parts information aswell.

PEagle

I found this : Mercedes-Benz M278 Engine Problems (V8 – 450, 500, 550) (lifeonfour.co), they mention it in the paragraph " M278 Engine valve guide wear "
However they do not provide a Mercedes technical document related to it.

juanmor40

Taken from https://www.catcar.info/mercedes/?lang=en&l=Y2xhc3M9PTF8fGNvdW50cnk9PTF8fHN0PT03MHx 8c3RzPT17IjEwIjoiQXNzb3J0bWVudCBjbGFzcyIsIjIwIjoiQ 2FyLUV1cm9wZSIsIjUwIjoiMjA3LjQ3MyAgICAiLCI1MiI6Ik1 hai4gQXNzeSBNIC0gRW5naW5lIiwiNTUiOiIyNzguOTIyICAgI CIsIjYwIjoiMDMgUEFSVFMgT0YgVU5JVCBQT1dFUiBQTEFOVCI sIjcwIjoiMDMwIENPTlJPRCBBTkQgUElTVE9OIn18fGNhdGFsb 2c9PUQ3MyAgIHx8Y2F0YWxvZzE9PTY5QyAgIHx8dHlwZT09Mjc 4fHx0eXBlMT09MjA3fHxzdWJtMT09OTIyfHxzdWJtMTE9PTQ3M 3x8YWdndHlwZT09TXx8YWdndHlwZTE9PUZHfHxtb2RlbD09Mjc 4LjkyMiAgICB8fG1vZGVsMT09MjA3LjQ3MyAgICB8fGRldGFpb GdycG51bT09MDN8fHN1YmdycD09MDMwfHxwYWdlNzA9PS0x

Also, a bit confused with the attached document at

5soko

I attached the most current Mercedes M278 part info in the first post aswell. The link and information you posted is for the M276 engine, this thread is for M278

juanmor40

You certainly did not read the attachment, and from previous answers you also seem to have an attitude to answer to forum members that do not conform to your ideas.

5soko

I did add in a 'haha' to show my humorous side in a previous post I wouldn't call any of this my ideas, more Mercedes ideas. (haha) But on a serious note, i apologize if my attitude came off as such. I'll go back and re-read what was posted to add any help i can. Group effort here! Knowledge is power.

juanmor40

No problem.

Keeping up with the cylinder topic, here is what I found for the M276


On the previously attached document, indicated the M276 used cast-iron cylinders. At the time of that report, the M276 was only Naturally Aspirated. However, it seems with the introduction of the M276 BiTurbo they moved to die-cast aluminum cylinder as the M278. I bet to reduce production cost and have a single casting process for all M276 3.0L and 3.5L and the M278.

it seems that by 2015, as you showed, they reverted to cast-iron on the M278. I now wonder if something similar was done for the M276 since the C/CLS/E/SL/S/ML/GLE/400 used that engine.

JettaRed

iTrader: (1)

I agree that it's not clear if the M276 3.5L NA engine uses cast iron cylinder liners or not. I think certainly the 3.0L bi-turbo uses K-Y jelly. The publication date for the info on the M276 NA engine was May 2010, so much may have changed. I'm curious to know if the M276 NA kept the iron liners as I have both engines.

MBNUT1

Is one takaway that the pre 2016 M278's should be avoided?

Baltistyle

I was able to read and follow along You’ve made a thread and provided info in your first post, info on the 278 engine. Not sure why anyone is talking about a 276. Thanks for the info. My takeaway is that if I were to have an issue with my157, the 278 might be a good block to build out if using a later engine.will an upper half of a 278 fit on the bottom of a 157? What are the build possibilities.

chassis

This thread is pretty interesting. I don't recall seeing iron liner documents until now. I joined this site in 2018 and have been pretty active. Strange...

My takeaways and questions:
- 157 engine should be avoided, this seems clear from the experiences reported on this site.
- 278 engine, if it has iron liners, seems capable of high mileage without scoring.
- 278 engine, if it has iron liners, could potentially be tuned to 157 levels.
- 276 engine does not have a reputation for scoring, does this mean it has iron liners?

@arsupisemnet if you could weigh in on the topic it would be appreciated, as to your opinion on the presence of factory iron liners in 278 engines.

JettaRed

iTrader: (1)

The M276 NA in the early days certainly had iron liners, while the turbo version did not. That is based on the two attached documents.

WRT why the M276 is being discussed, the 278 and 276 are roughly 6 and 8 cylinder versions of the same engine family except for some slight differences. So, the comparison between the two relative to their differences may be helpful.

chassis

Thanks. Agree that it is germane to talk about 276 and 278 in this thread. 274, 276, 278 and 157 are variants of the same engine architecture, were designed in the same era and share many common components and manufacturing processes.

arsupisemnet

You can tune 278 to stock 157 hp just jacking up boost levels, but it is as much you can go, beyond will bend rods. Both engines has same quality. Iron liners been installed in s550 e550 and some other earliest models, GL got engines in 2014, basically all of them Alusil.
Realistically speaking there is nothing wrong, you got strong car, with a strong high performance engine, just not used to comparing to Toyotas...
My own engine actually still working after rebuild but need to change head gaskets, been overheated twice (same disease plastic fittings) , so head bolts as of now is gone, and i know it because it is spitting coolant after my rare rides (i roll on the turbo all the time if you understand the meaning), where gf driving it around with no issues.
Now about building Frankenstein - you can fit m157 heads on m278 but you cant do opposite. I wouldn't even try, since it is not worth doing that, just find machine shop to install liners and order custom pistons and rods, i would say regular custom made wont cost a fortune, unless you want to showoff with overpriced italianrp made in same china...

arsupisemnet

I would not rely on Nano Slide either, it is same new technology basically plasma spray of nicker iron compound on cylinder walls similar to Fords. Those you can't even hone it will take coating away.
Either way proper way of doing things - order custom ductile iron sleeves (preferably flanged) with a wall thickness of at least 0.1 inch. Will cost from 1200 to 1600 depends on manufacturer
Install it in any machine shop willing to take a job - probably 1500 to 2000 labor depends on machinery
Order custom forged pistons - those will cost you about 1500-2000 - cheap compare to MB originals, but these are forged, so you can drop any mf tune
Buy chineese forged rods - about 700 for a set with arp like bolts.
If you have some change left order inconel custom exhaust valves - at about 25 buck a piece (still cheaper than MB)
Put it back together. Put stage 2 or stage 3 tune...
One thing is head bolts - find arp studs or buy weistek for 900

kevm14

Whoa just noticed this thread.


So what's the verdict on this? All 157s are Silitec? Or later ones are Nanoslide but we don't know how much better that really is?

"Later" 278s are cast iron liners? Like how later, what VIN or in what general model years of the 222 and 166? I am counting out the 212 because the E550 became rare bird after 2014 it seems.

thtguy

So doing all the researches... with this change, are they actual cast iron liners or or is it a ferous spray in lining like Nanoslide?

kevm14

I read some of the attachments that I missed before. What I learned is that no matter what cylinder material/coating you have, they are all susceptible to heavy scoring. The question is, are the cast iron cylinder liners the most durable? Do we know this? Or are we just assuming this? They clearly showed some nasty damage in the M278 doc for cast iron liners, so it's not like they are impervious to the issue.

Maybe we should all just swap out our injectors at 100k as it seems like a cylinder slowly going more and more lean (due to injector carbonization) is a huge contributor to the issue.

chassis

All non-iron liners are junk and subject to scoring. Doesn’t matter if the coating is unobtanium or gutta perca.

Iron liners are best practice. Still can be found in some engines, for example the VAG EA839 2.9/3.0 V6.

chassis

I have asked in several threads on this site and rennlist if iron lined engines have had scoring reported. No one that I have seen has reported scoring on engines with iron liners.