Quote:
Originally Posted by Green-Eggs
I grabbed it from the wiki, and posted it here, but I think it was only added two days ago.
|
The WIKI has been updated, but is still showing the incorrect specs 0.0004" - 0.0013" as per attached image.
On the WIKI update you are also quoting data from MAHLE Motorsport from Berts visit (incorrectly) as relevant to the OE bearings. i.e. rockwell hardness.
The following statement is also completely wrong "The combination of a lead tin alumina overlay with VP2 improves wear resistance by a factor of two when compared with a lead tin copper overlay"
I believe the confusion here arises from
BE V2 bearings which are Clevite F material, which is MCB2 base (cast lead copper i.e.bronze), nickel barrier layer and lead, indium , tin with alumina (aluminium oxide) overlay, not silver oxide.
Quote:
Originally Posted by Green-Eggs
Is this an actual technical bulletin from Mahle, separate from the technical document that you posted from Mahle Motorsport? It would be nice to see that as well.
I can speak for myself because I believe that I posted the comment about "credible but unverified." Posting a document that contains a quote that can't be verified independently is what I was talking about. Maybe you and Bert can discuss and figure something out. He told me that you two have been chatting and that he's in the process of improving the wiki. I think that's when he posted this updated info because looking at the page history, it says it was added two days ago.
|
So a world renowned and respected manufacturer that is active in ALL motorsport from F1 down produces a technical bulletin stating the OEM clearances, calculated from the OEM drawing with the OEM development data that they have as they purchased the company that produced the OEM parts and you want more proof? Yet if I question the logic posted about requiring an additional .005" clearance I'm pointed to the ACL catalogue?
You misquote the Clevite paper stating that .001" per inch of journal is "industry standard" when it actually states “For most applications .00075 to .0010” (three quarters to one thousandth of an inch) of clearance per inch of shaft diameter is a reasonable starting point” Which incidentally is exactly where the now released data (from 2 sources) puts the OEM bearings, yet you question the validity of the MAHLE data?
Please, have the same standards of scrutiny over data that appears to agree with your claims as the data that appears to disagree.
Quote:
Originally Posted by Green-Eggs
I wouldn't expect the measured results at the wiki to change unless the measurements with the new equipment change. However, if you have your own measured results, then this would be the thread to post them.
BTW, did you see the comments only a few posts above about using MODE instead of AVERAGE? IIRC, the guy "swamp" referred in that post is a statistician by trade. If you wade through this thread, you'll see his participation and disagreements in plenty of places.
|
Your measured clearances don't align with your wall thickness measurements.
I have checked the claim on mode vs mean across all your data (yes, I am that sad!) Here are my results
ACL H - Mode is used
ACL HX - Mode is used
VAC Clevite - Mode is used
BE V1 - Mode is used
BE V2 -
MEAN is used
088 /089 - cannot correlate claimed clearance to mode or mean
702 / 703 - cannot correlate claimed clearance to mode or mean
So no consistency.
More interestingly the BE V2 clearance claimed as well as mode clearance or mean clearance is not theoretically possible with the wall thickness span quoted and the crank data used. And none of these marry up to the .0024" claimed elsewhere on the forum.
Bert is aware of my concerns and what I personally consider to be pretty fundamental errors in the WIKI. Unless you can independently verify the measurement data, why should I trust this, especially when it doesn't marry with the wall thickness measurements also taken and published?