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I’m having a hard time finding the procedures and info about rebuilding the S85 and repairs anyone know a good source
Where to find info/procedures to rebuild a S85
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Newtis.info or ISTA will have the documentation for any bmw repair procedures.
There's a couple YouTube videos with engine teardowns as well. I don't think there is an extensive step by step build up video but I only searched Google for maybe 30 seconds.
Why the rebuild? Are you a new E60 owner or building the S85 for a swap?
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No just found a project M5 in California for a good price and needs a motor rebuild since it has a couple bent rods, I own a 545i snd just looking for a new project
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Agreed and a new block is 1000 by itself
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For info about rebuilding I’ve tried Ista and newtis and no luck, does anyone have any other recommendations for sites, like all data or whatever shops use, this is such a well known and talked about engine yet nothing
huh, less than i thought. realistically though you probably need a new long block as there's likely shrapnel everywhere.
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You’re not going to have one page that’s titled “engine reassembly” or whatever. But everything should be there in steps. Think like you’re assembling any other engine and search for what step you’re on. For example, there’s repair instructions for “replacing the piston rings on all pistons” (document 11 21 671). Another page is “removing and installing/replacing all pistons” (document 11 25 530). Anything that requires torques or replacing tty fasteners will have those requirements in a table linked in the page.
ISTA and newtis will have the same info, I prefer newtis most times because it’s quick to access and I can do it on any device with a web browser. I just looked up those two pages above on my phone.
ISTA and newtis will have the same info, I prefer newtis most times because it’s quick to access and I can do it on any device with a web browser. I just looked up those two pages above on my phone.
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A junk block maybe. For a 'new' block you're missing a digit.
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@herrubermensch when did u say you're going to start tackling S85s?
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Historically, we have done S85 block conditioning and even sleeving. In fact, we have one S85 sleeve job left to do for a board member. But I about a year or so ago, I moved the operation solely to building engines and machine work for those builds; we won't do the machine work on a one-off basis. We will do S62, S54, S65, and S85 shortblocks, longblocks, cylinder heads, and fully dressed PNP engines, but nothing less than any of those. So the answer is: Now!
For those that do not know, my shop, Partee Racing, LLC and it's wholly-owned subsidiary, The ///Machine Shop, LLC, specialize in alusil block reconditioning and builds. We deck and square alusil blocks in our RMC V40 CNC, then use a Sunnen SV-10 to bore the block with diamond stones to within .002" to .005" of finished size (i.e., within .002" to .005" of the bore diameter required based on the piston diameter, piston material, and desired piston-to-wall clearance), then use 500 and 600 grit stones sequentially to get to finished size. Then the block moves to a manual hone where we use felt pads and the special alusil paste to hone each cylinder for a specific time period at a specific pressure (as measured by the amps pulled by the hone), then clean the bore with brake fluid and confirm its surface roughness parameters with a surface profilometer. We shoot for specific Ra, RpK, RvK, Mr1, and Mr2 ranges. Once we hit them (our formula usually does so with one or two tries), we move on to the next cylinder. It is a pain-staking process that not many shops understand how to perform, know the necessary technical parameters to achieve, or are willing to take the time and patience to do right. I think we are one of two or three shops in the nation that do it, and we think we do it the best of those three.
We have spent hours and killed many an alusil block developing our alusil reconditioning recipe and identifying the technical parameters to achieve. We recently received a brand new S62 block for a build, but it arrived damaged and was replaced. We measured the surface roughness specs of the damaged new S62 block cylinder walls and compared them to our specs. As a result of that comparison, when we do a build with a new block from BMW, we ALWAYS, bore, hone, and recondition the cylinder walls. BMW does a fine job, but it just doesn't achieve the specs that we do. We have consulted ring industry experts who have confirmed that our specs are superior, and the performance of our engines also is a testament to that.
One immediately identifiable reason for this phenomenon: BMW doesn't use torque plates when they bore, hone and recondition their blocks! We installed a set of heads on a brand new BMW block without a reciprocating assembly and used a bore gauge from underneath to determine whether cylinder heads would distort a new BMW block's cylinder walls or bring them back into perfectly round (as would be expected if a torque plate had been used when the block was bored and honed). The heads distorted the cylinder walls. The same block bored and honed with a torque plate by us then came back into perfectly round when cylinder heads were installed. That is what you are after, viz., cylinder walls that are perfectly round with the right roughness specs when cylinder heads are installed. Alusil distorts quite a bit when head bolts are installed, much more so than a cast iron block. One HAS to use a torque plate on BOTH banks when boring, honing and reconditioning or you will not achieve the best dimensions under operating conditions, i.e., when the heads are installed.
Apologies for the protracted response, but the posters in this thread seemed interested in the intracacies, so I indulged!
--Peter
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You are welcome. Please forgive my verbosity, but I love this stuff!
Indeed it does. Out of round cylinders necessarily allow more blowby.
We REM polish all but journals, then use cork polishing bands with a hand held electric polisher to polish the journals. That does not effect any material dimensional change in the diameter of the crank journals. If any such change is necessary, we generally will use a different crank, as crank grinding is rarely done well or accurately, and when it is, it is prohibitively expensive, more so than using a new crank.
--Peter
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Lang racing welds and regrinds cranks for $800
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I stand by my comment.
—Peter
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