Rebuilt 55k engine questions
To answer my own question on the break in oil. I did some research and most companies couldn't confirm 100% if their oil is fully compatible with our alusil bores. Brad Penn, Liqui Moly, etc. I wanted to make sure I put the correct oil after carrying all this work so cutting a corner with just an off the shelf break in oil was not an option for me. Pretty much everyone I spoke to kept insisting I contact Mercedes-AMG for the confirmation. I even spoke with engine specialists at Brabus and Vaeth and both said they use fully synthetic, service oil in their cars during the break-in, not a special break-in oil. After giving AMG a call I was given an email to send my request to: amg-technik@daimler.com.
It only took AMG a couple of hours to come back with a list of fluids and oils recommended for our cars: http://bevo.mercedes-benz.com/bevoli...ets-sort1.html
I spent some time going through the list trying to find anything relevant and indeed, there was a document for engine oils: http://bevo.mercedes-benz.com/d/d/en/Spec_221_0.pdf
Interestingly enough Page 7 of above file contained information on break-in oils. However, what I was looking for - a table with engines and approved break in oils - wasn't there. Instead there was a reference for yet another document (223.1) which is not available in the big list of specifications AMG emailed first. Here's what it said on page 7:
used with which engine is available on Sheet 223.1."
I tried looking up this specification online but to no avail. Again O emailed AMG asking to provide any insight on that specification and oils approved for M113K. 2 days later, I received a reply:
Anyway, here's the excerpt from dealer's WIS:
The general rule is that the binding oil quality (MB sheet) can be found in the respective vehicle operator's manual.
This table only contains oil types for engines that are currently in production!
Information on unlisted, older engines can be found in the vehicle operator's manuals or the maintenance procedures. Vehicle-specific special considerations must also be observed for the use of the engine oils."
Then the mechanic who worked on my cars had a brilliant idea - M275. Essentially, a block from the same era, with same alusil coated bores as in M113 and still in production. The rest was pretty easy. According to 223.1, the approved break-in oil for M275 is 225.10 or Mercedes p/n A 000 989 78 01 10 (note the 10 in the end).
Mercedes describe this oil as




Glad you found the right oil for the break in process. Too bad AMG was giving you lip service.




Alusil is NOT a coating. It is the block material. It has a high concentration of silicon crystal structures when it is cooled after casting.
With this silicon, the boring and honing process in the final stages works to chemically wear away the aluminum and only leave the crystal structure of the silicon behind.
With that said, an alusil bore should NOT looks like it has a "cross hatch" pattern. It actually more has a dull-matte mono-color finish.
This is just the internet, I am just a guy, very far from you, talking about this - but I must stress how much you need to be careful -
The picture you are showing of your bores looks VERY VERY WRONG. Also, you are mentioning that someone said they used a "stone" on the bores. Final honing (technically lapping) with alusil is specifically with an AN-30 paste and FELT PADS. It does not materially change the dimensions of the bore from the previous last boring stage.
Again - NO stones, no "dingleball" hones with alusil. FELT PADS. AN-30 paste.
You may not give crap what people say on the internet - but spend some time on the research for this before you put that engine together. It DOES NOT look right if those are the stock alusil bores.




https://mbworld.org/forums/w211-amg/...5-project.html
Re Alusil. I've seen some refer to alusil as coating, which I appreciate can be wrong. It is an alloy.
Re stone. The balancer just referred to it as "stone" but mentioned it was very soft and felt like. I will ask again what he used, just to clear it but I'm almost certain he got it from a specialist for alusil.
Re crosshatching. It is very, very light. In fact, not only it didn't change the dimensions of the bores, it didn't remove the scoring which is still visible in some cylinders. It is not much of a honing even, just a very light pattern of grooves for the rings to bed.
Btw, here's an article describing the honing of alusil bores as a 3 step process:
http://www.sunnen.com/NewsDetails.aspx?NewsID=11
Last edited by Alex L; May 26, 2014 at 06:07 AM.



