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01-02-2024, 02:08 PM | #46 |
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Because BMW had finally disclosed the nominal spec and tolerance range for the clearance so BE made revisions accordingly, but there's no substituting for detailed measurement of your rod journals, but that's only practical if your crank is out.
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01-02-2024, 03:26 PM | #47 |
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Hmm, interesting. From what I understand BE state clearande (nominal, target clearance) based on the shaft numbers they earlier estimated (believe from a number of measured shafts). Wonder why the target clearance all of a sudden would change, if they revised the shell according to BMW disclosed spec, or do I miss something?
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01-02-2024, 05:55 PM | #48 | |
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You will also notice that the same language and "specifications" are provided for ACL, King, VAC, and others. Important to understand that it would be inconsistent of the wiki page to have different definitions for different manufactures. So, to say it one last time: these are all measured clearances and can be verified based on the actual measurements found on the wiki page. When a manufacture provides actual specifications, then you will see a separate section entitled "Theoretical Clearances." Theoretical clearances are calculated clearances based on manufacturer's specifications. These are based on measurements. The target clearance specification has never changed, not even since V1, but manufacturing processes do change. Therefore, BE will update the shell thicknesses on occasion to get the measured clearances closer to the target clearance specification. |
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DrFerry6803.50 deansbimmer3977.50 |
01-02-2024, 05:58 PM | #49 |
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Not correct. BE clearance specification has never change since the beginning of time. But tweaks were made to shell thickness (4-times for V1, 1-time for V2) to get the measured clearances closer to the specified clearances. The target clearance was, and always has been 0.0024 inch on a nominal journal. This target clearance specification has not ever changed.
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DrFerry6803.50 deansbimmer3977.50 |
01-02-2024, 05:59 PM | #50 | |
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DrFerry6803.50 |
01-05-2024, 09:04 AM | #51 | |
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Perhaps, you're taking specific issue with how I worded the sentence to say target clearance, in this case 0.0024, which I have no issue with. As for this comment, it's pure a garbage response. I don't make or sell bearings, I'm not a competitor. I was an early customer. I've used BE on 2 of my builds (oh I actually did sell a 3rd set since a friend wanted a set and couldn't get them in late 2019). The others I did were ACL because the customer wanted ACL and they were available with BE bearings were unobtainable. |
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01-05-2024, 12:42 PM | #52 | ||
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03-19-2024, 08:32 AM | #53 | |
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"The target clearance was, and always has been 0.0024 inch on a nominal journal. This target clearance specification has not ever changed" If this is the case why is nominal clearance stated for V2 0.00268 inch ??? |
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03-19-2024, 10:09 AM | #54 | |
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03-19-2024, 02:29 PM | #55 | |
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03-19-2024, 03:58 PM | #56 | |
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03-19-2024, 05:01 PM | #57 | |
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If I take BE V2 which is an uncoated bearing, I have (from the wiki) the following wall thickness Upper - 1.9939 - 2.0066mm Lower - 1.9812 - 1.9939mm If I use the following sizes crank / housing sizes Housing - 56.013mm (OE published max size) Journal - 51.9811mm (wiki states 2.0465" used for calculations) using the wiki formula for calculating theoretical MAX clearance BEmax - JDmin - LWRmin - UPRmin - (2*CTmin) gives the following 56.013 - 51.9811 - 1.9812 - 1.9939 - (2*0.00) = 0.0568mm (.0022") This calculated theoretical max clearance is marginally smaller than the target 0.0610mm (.0024")? What data is being used to calculate the target clearance? |
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03-19-2024, 06:21 PM | #58 | |
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There's definitely a difference between theoretical values and measured values, and I think that's the benefit of data like this. |
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03-20-2024, 05:16 AM | #59 | |
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The use of the nominal rod size was NOT a mistake. I used this figure as it has been stated that the BE target clearance is based on this. Yes, I accept that it IS technically incorrect, but I was following how BE is stating they are calculating. So if I rerun the numbers using ACL crank data I get a max theoretical clearance of 0.0629mm (.002476") Now this is still very close to the claimed target clearance of .0024" Given the target clearance is also theoretical I can't see how this figure can be achieved with out all bearings being on minimum wall thickness and crank / housing on max limit? So how is BE arriving at the .0024" target clearance figure? The industry standard for quoting a nominal clearance figure would be to use the mean figure between theoretical minimum and theoretical maximum. ACL does this and my calculations concur with their claims. ACL published 0.035mm (.001378") My calculation 0.0355mm (.001398") If I then use the same for BE (using ACL crank sizing) I get the following Theoretical Max 0.0629mm (.002476") Theoretical Min 0.0085mm (.000335") Theoretical Avg 0.0357mm (.001406") So if we want to compare apples with apples for published clearances we need to calculate in the same way, otherwise the data is meaning less for comparison purposes. |
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03-20-2024, 04:25 PM | #60 | ||||
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So, let's pull one at random: ACL H-STD. The smallest measurement was 2.04840. Using maximum journal size, subtract 2.04680, giving clearance of 0.00160. The largest measurement was 2.04875, subtract 2.0464, giving clearance of 0.00235. The mode (not average) measurement was 2.0484, subtracting 2.0465, giving clearance of 0.00190. The decision to use mode instead of average on ACL is a different discussion. But it's easy to verify that these are the exact values posted on the wiki page and how they were derived exactly as you suggested above. If you've found a mistake in the wiki, then please point it out and explain how it doesn't follow this same convention. Quote:
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03-20-2024, 05:49 PM | #61 | |
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But I'm still struggling to understand how a target clearance of. 0024" can be achieved with the stated wall thicknesses? Please explain how this figure is arrived at. |
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03-21-2024, 10:25 AM | #62 | ||||
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It is correct to state Theoretical max clearance for the nominal journal size that the stated BE target is based on. Quote:
ACL - 1.998mm King SV - 1.996mm King GPC - 1.996mm MAHLE - 1.997mm BE - Assumed 2.0066 & 1.9939 from the wiki data All of the above also publish crank and housing size data except BE. Granted, they are not publishing tolerances or minimum wall thickness, although these are generally known for at least ACL (8um) & MAHLE (9um) So from the above data we get a maximum wall thickness as follows: ACL - 2 x 1.998mm = 3.996mm King SV - 2 x 1.996mm = 3.992mm King GPC - 2 x 1.996mm = 3.992mm MAHLE - 2 x 1.997mm = 3.994mm BE - ??? Assumed 2.0066 + 1.9939mm = 4.005mm from the wiki data The above also assumes that for BE you pack one of each size bearing Quote:
The WIKI also doesn't state that mode rather than median is used. I would be interested in why mode rather than median was used. I remain to be convinced that this is a fair comparison, any parts with a wider tolerance show "Improved" clearance. Quote:
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RalliartRsX28.00 CSBM52860.50 |
03-21-2024, 01:21 PM | #63 |
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Why is there 4 or more threads going at the same time about the same thing. It's to hard to follow along any more.
Please make a thread dedicated to discussing the engineering and technical aspects of bearings. Leave the other threads to their original point. |
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drago7407.50 Assimilator1622.00 |
03-21-2024, 02:56 PM | #64 | |
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https://www.m3post.com/forums/showthread.php?t=892838 |
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03-23-2024, 08:24 AM | #66 | |
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Sorry you don't have the capacity to grasp the concepts. Perhaps a little more reading will help you |
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