|
|
08-21-2012, 07:07 PM | #67 | ||||
Lieutenant General
638
Rep 10,404
Posts |
Quote:
Quote:
Quote:
Quote:
What are these benefits exactly? One reason (among many) we have rings is for less sensitivity to piston/cylinder fit. Come on get with the program. You think that in regards to piston/bore fit that hand measurements, hand bin-ing and hand installation is less expensive in these volumes than doing so by machine? That just doesn't make sense. There are a few possibilities here from my perspective, again somewhat speculative, since I have no first hand/second hand knowledge of this engine assembly process. In most automotive assembly processes, body, engine or otherwise there are sub-processes that can be done less expensively by hand as opposed to by machine. Thus some processes for this engine are done by machine, some by hand. MB then uses this as a marketing opportunity to appeal to the outdated notion that by hand is somehow high-end, magical or better. I highly doubt that the entire volume production of this MB engine has hand inspected, hand sorted and hand installed pistons purely to improve the quality or performance of the engine. In fact, even without direct knowledge, I would be willing to bet this is not the case. Money drives just about everything and it will be driving this as well. Ease up on the insults, especially when they are 100% without basis. I have no evidence, do not believe and did not state that BMW M is doing anything appreciably any different than MB here. I also never said BMW M is doing anything sub-micron. GET YOUR FACTS and READING ABILITY SORTED OUT. Perhaps the senility of your old age is affecting your reading comprehension here? What I said is the BMW M (and BMW in general) has many single digit micron tolerances and this follows simply because the S52 already has some and improvements have been made since then.
__________________
E92 M3 | Space Gray on Fox Red | M-DCT | CF Roof | RAC RG63 Wheels | Brembo 380mm BBK | | Vorsteiner Ti Exhaust | Matte Black Grilles/Side Gills/Rear Emblem/Mirrors | | Alekshop Back up Camera | GP Thunders | BMW Aluminum Pedals | Elite Angels | | XPEL Full Front Wrap | Hardwired V1 | Interior Xenon Light Kit | Last edited by swamp2; 08-21-2012 at 07:14 PM.. |
||||
Appreciate
0
|
08-21-2012, 08:27 PM | #68 | |
Captain
146
Rep 795
Posts |
Quote:
|
|
Appreciate
0
|
08-21-2012, 10:54 PM | #69 |
Major General
2793
Rep 6,791
Posts |
Folks, a modern industrial process for tolerance matching would never use hundreds of bins, that is so last millennium.
In modern manufacturing, this type of problem is typically solved by measuring part A size (piston or piston ring in our case) then auto-barcoding the tolerance on it, then storing it in a known location in an automated shelving/delivery system. Then come assembly time, part B (the cylinder bores in our case) can again be measured in real time, then a specific piston or ring can be selected for each bore from the pool of available parts. This no binning system would have the capability to match pretty much any tolerance given a large supply of pistons or rings, which BTW is exactly the process of matching parts that an engine builder does. It's a simple workflow which can be implemented with a few sensors and an automated shelving/warehousing system. Now I'm not saying this is what BMW is doing because I am not privvy to their secrets, but if it would provide such great benefits then they could easily implement something like this to offer tolerance matching that can be easily on par with, if not better, than the corresponding human process. My impression is that any potential benefits are overstated. I mean, are we talking about the last 10%, 1% or less? Nobody can tell...
__________________
2018 F80 Santorini 2019 Z4 30i 2022 X2 M35i |
Appreciate
0
|
08-21-2012, 11:56 PM | #71 | |
Lieutenant General
638
Rep 10,404
Posts |
Quote:
It's sure is easy to type BS with no supporting evidence rather than explain your argument...
__________________
E92 M3 | Space Gray on Fox Red | M-DCT | CF Roof | RAC RG63 Wheels | Brembo 380mm BBK | | Vorsteiner Ti Exhaust | Matte Black Grilles/Side Gills/Rear Emblem/Mirrors | | Alekshop Back up Camera | GP Thunders | BMW Aluminum Pedals | Elite Angels | | XPEL Full Front Wrap | Hardwired V1 | Interior Xenon Light Kit | |
|
Appreciate
0
|
08-22-2012, 02:08 AM | #72 | |
Captain
146
Rep 795
Posts |
Quote:
On another side note: http://www.worldcarfans.com/11208164...-mercedes-benz Last edited by bimmerj; 08-22-2012 at 03:57 PM.. |
|
Appreciate
0
|
08-22-2012, 02:56 AM | #73 |
Major
147
Rep 1,440
Posts |
Personally, i would trust a machine built part more than a hand made one unless i am sure that particular craftsman is of top notch credential. Human is often the weak link when it comes to consistency.
__________________
- Frozen Grey F10 M5 DCT
- Rosso Corsa 458 Speciale Sold - Frozen Grey E92 M3 Sold |
Appreciate
0
|
08-22-2012, 04:39 PM | #74 | |||||||
Colonel
99
Rep 2,000
Posts |
Quote:
Second, you had your chance to back off your micron or smaller position back in note 64. When I mentioned that you were dreaming, you said: "Sorry, wrong." Too late to weasel out now. Quote:
Quote:
I'd bet the Porsche guys were testing blow-off valve after blow-off valve as well, looking for the ones that would maintain the highest permissable boost within spec. Quote:
To repeat myself, the other reason for hand assembly is performance. As a for instance, you can bet that every 911, every M3, every 458 and anything else competing in the ALMS has a lovingly hand built engine. Quote:
As to Mercedes dishonesty, you have no direct knowledge of that, and of course you don't believe that their 6.2 liter engine weighs the stated 436 pounds, either. So we know that you have something of an attitude about MB, therefore dropping your credibility in regard to MB issues down to near zero. Quote:
I personally feel that improved quality and performance is the chief reason for them hand assembling the 6.2, but "improved quality and performance" is a statement that needs filling out, or a better definition, if you will. Where are they starting from? This is AMG's first engine, after all, and what if they've got a bit of a glitch somewhere, sufficient to necessitate hand assembly, or at least to make that the preferred method? Quote:
As mentioned, you had the ability to back off sub-micron in note 64, and didn't. Don't try to weasel out now. Finally, I've kept my hand-built comments narrowed to custom fitting of pistons, and expect that normal folks reading this string will easily understand those comments. Particularly the OP. Bruce PS - In regard to Chevrolet, they hand assemble Corvette engines fitted to the Grand Sport stick cars, all Z06s and all ZR-1s. A year or so back, I asked a Corvette engineer (during the Corvettes at Carlisle massive show) about why they did this. He said that they got a bit of power out of hand assembly, but mostly they did it because from their perspective, these particular models were going to get beaten like a red headed step child, and would last better under those conditions. I mention this because it's another reason why manufacturers may do this, and this subject is not quite as cut and dry as you seem to think. Last edited by bruce.augenstein@comcast.; 08-22-2012 at 05:25 PM.. Reason: Spelling |
|||||||
Appreciate
0
|
08-22-2012, 10:38 PM | #75 |
Lieutenant
46
Rep 516
Posts |
I am going to venture out and say you have never built a motor on your own. Between constantly checking tolerances and every bolt and clearances, it is absolutely better when one person does it. Ive built a few motors myself for hot rods and it is definitely a love affair for me.
You have obviously forgot about German brands and they're pride. It might be marketing, but its also a sense of pride to say something is handmade. When was the last time you hand built anything and signed your name on it with pride.
__________________
Current Stable: 6 Drivers + 5 Projects
|
Appreciate
0
|
08-24-2012, 12:46 AM | #76 | |||||||||||
Lieutenant General
638
Rep 10,404
Posts |
Quote:
Quote:
Quote:
Quote:
Quote:
Quote:
Quote:
Quote:
Quote:
Quote:
Quote:
Believe what you want, it is a lot of traditional hod-rodder/race team type of mentality. For PRODUCTION vehicles the manufacturing is all about the volume, capacity, assembly time and last but still greatest COST.
__________________
E92 M3 | Space Gray on Fox Red | M-DCT | CF Roof | RAC RG63 Wheels | Brembo 380mm BBK | | Vorsteiner Ti Exhaust | Matte Black Grilles/Side Gills/Rear Emblem/Mirrors | | Alekshop Back up Camera | GP Thunders | BMW Aluminum Pedals | Elite Angels | | XPEL Full Front Wrap | Hardwired V1 | Interior Xenon Light Kit | |
|||||||||||
Appreciate
0
|
08-24-2012, 12:58 AM | #77 | |
Lieutenant General
638
Rep 10,404
Posts |
Quote:
I have built motors by hand, myself but only very simple single cylinder ones contrasted with any modern multiple cylinder automobile engine. Human error is a huge factor in any process and that is why industrial, manufacturing and reliability engineers prefer to remove them from the process. Your point only helps mine, it does not provide an argument against it. I understand German manufacturing pride just as well as American manufacturing pride, thank you very much. I know dozens of engineers from both countries and I am a (recovering) Mechanical Engineer myself. I've done design, manufacturing engineering, tolerance studies, test engineering, test and assembly tooling design, assembly automation, fatigue/static/dynamic testing, thermal testing, physics based product simulation, product data management and on and on. Perhaps ask others involved in the discussion their relevant professional experience... Although I don't do any of that professionally any longer I continue to build a great deal of things with my hands. I don't sign my name on them but you can be assured there is an enormous degree of pride and perfection in the things I build, it's simply my nature. Any other questions?
__________________
E92 M3 | Space Gray on Fox Red | M-DCT | CF Roof | RAC RG63 Wheels | Brembo 380mm BBK | | Vorsteiner Ti Exhaust | Matte Black Grilles/Side Gills/Rear Emblem/Mirrors | | Alekshop Back up Camera | GP Thunders | BMW Aluminum Pedals | Elite Angels | | XPEL Full Front Wrap | Hardwired V1 | Interior Xenon Light Kit | |
|
Appreciate
0
|
08-24-2012, 07:40 AM | #78 | |
Brigadier General
101
Rep 3,246
Posts |
Quote:
I love this shit! I'm no engineer or anything like that (ex pit trader) but this is some interesting shit. Keep going guys, don't stop now
__________________
mods: track ready stuff
|
|
Appreciate
0
|
08-24-2012, 09:51 AM | #79 |
Grease Monkey
301
Rep 2,646
Posts
Drives: 2011 E90 M3,1994 Euro E36 M3/4
Join Date: Apr 2006
Location: Fort McMurray, Alberta, Canada
|
I have to agree with Bruce on some of his statements. As someone who works with engines for a living I can tell you that during a rebuild or after a block or crankshaft comes back from machining you measure, measure, measure and then measure again.
By simply taking parts off of the shelf and putting them together without measuring, many times can result in failure since the tolerances are not within stated dimensions. I don't know if you guys remember the infamous "GM Piston Slap" fiasco a few years back. That issue started when they stopped the hand fitting of pistons in their blocks and relied on the tolerances of the pistons and bores being within stated dimensions. I do agree that modern automated machining can make extremely tight tolerances and is very good, but, if you get out your feeler gauges, vernier, micrometer, or bore gauges you can actually show the areas where the measurements are barely within tolerance. A good engine has all of its measurements evenly within tolerance and not all over the place with some on the high side and some on the low side of spec. I can guarantee you that there is some human involvement when building any good high performance engine. Even if each and every engine is not hand assembled, some of the parts or even a complete engine will be pulled from the assembly line every so often and measured to verify that all of the dimensions are indeed within spec and as a form of QC. One final thing, even the S65 which BMW does not claim is hand assembled has three sizes for main bearings. If you look at parts list the bearings have colours assigned to them. This is due to the main bearing bore variance and the need to keep the oil clearance proper. Now I don't know if they hand measure and then select the bearings or if they have a machine measure but either way this shows that even high tech machining equipment can have some variance that has to be made up for with correctly sized bearing shells. As for pistons, the S65 only shows one piston size. Since Mahle makes the S65's pistons and they are known as one of the best piston manufacturers in the world, they probably verify dimensions before shipping them, and BMW may very well check all of the bores of the blocks after machining and only build engines out of the ones that meet their specs. The moral of this post is that having a skilled craftsman measuring and building you an engine is definitely worth it, as good as machines are, many times we have had to send back brand new parts that were supposed to be within spec but were indeed not even close. If you work with this stuff all the time you realize that machines, while as amazing as they are, do not always build the perfect parts. Finally, Even with automated assembly there is always a programmer or machine operator that has to be added into the equation too! P.S.: Swamp, their is indeed evidence that hand fitting of pistons does offer benefit and it is not merely anecdotal, it is a fact and has been proven. While it may not always be measurable in terms of power, it will definitely be measurable in longevity. Excessive piston to bore clearance will result in piston slap and piston to bore clearance that is too tight will result in scuffing and excessive wear. Over time piston clearance that is too tight or too loose will make the bores wear out of round which can eventually lead to oil burning and/or loss of power. Basically if you want an engine to run quiet, make power and last, you need to ensure all of your measurements are nicely within spec. ( I know you know this but I thought I would add my $0.02)
__________________
Last edited by BMRLVR; 08-24-2012 at 10:11 AM.. |
Appreciate
0
|
08-24-2012, 11:14 AM | #80 |
Lieutenant Colonel
1081
Rep 1,761
Posts
Drives: S2000, MacanS, M4CS
Join Date: Oct 2006
Location: NJ
|
AMEN.
__________________
2020 ///M4 CS, Alpine White, DCT
2018 ///M2 LCI, Metallic Orange, 6MT, Exec Pkg, Apple.. Sold Instagram: Tommys911 |
Appreciate
0
|
08-24-2012, 11:26 AM | #81 |
Ya ya ya, I am Lorde, ya ya!
267
Rep 2,772
Posts
Drives: E90 M3, 2015 SQ5
Join Date: May 2011
Location: Snig
|
My dad's 2004 Terminator Cobra has two signature stamps on the motor.
|
Appreciate
0
|
08-24-2012, 12:39 PM | #83 | |||||||||
Colonel
99
Rep 2,000
Posts |
Quote:
Quote:
By the way, it's ifs ands or buts. These items are not possessive. Quote:
Listen, let me concoct a Mercedes meeting back in, say, 2010. The bean counters are getting concerned because the 6.2 liter V8 is selling so well that they're leaving money on the table with each one by not automating. Then the CFO says that within two years they'll begin ramping down 6.2 liter volume to a projected nnnnn units in 2012, reduced to nnnnn units in 2013, and phasing out totally by 20mumble-whatever. If that's the case, then would tooling up for volume production in this fiscal year of our Lord make sense? Let's see, mumble-mumble, carry the two, mumble-mumble. Nope! It's close, but we should carry on. OK, I made that up, but what I'm trying to convey is that things are not as simplistic as you seem to (routinely) think. Quote:
Nonsense. I'm on record with this in note 28. You didn't fire up until a good while later. Quote:
Quote:
Quote:
Quote:
Sheesh. Quote:
Finally, an additional note on Chevrolet. The engineer and I didn't speak about this, but I'm pretty damned sure that the costs to run the Grand Sport stick engines through the hand build line were much less than they would've been had that line not been already justified to service the limited production Z06 and ZR-1 engines. Last edited by bruce.augenstein@comcast.; 08-24-2012 at 01:29 PM.. Reason: Spelling |
|||||||||
Appreciate
0
|
08-24-2012, 12:46 PM | #84 | |
Second Lieutenant
5
Rep 273
Posts |
Quote:
Different philosophies. AMG was racing cars and Mercedes winning formula one championships before BMW knew what a sports car was. They are both great motors. Get over it.
__________________
2015 Porsche 911 C2S | 2019 BMW X5 50i | 2020 Land Rover Discovery
2007 Ducati Monster S4RS | 2016 BMW RNineT | 2018 Aprilia RSV4 | 2019 Speed Triple RS |
|
Appreciate
0
|
08-24-2012, 01:09 PM | #86 |
Second Lieutenant
5
Rep 273
Posts |
I replied before reading (obviously) but didn't care. I would have made my point regardless.
__________________
2015 Porsche 911 C2S | 2019 BMW X5 50i | 2020 Land Rover Discovery
2007 Ducati Monster S4RS | 2016 BMW RNineT | 2018 Aprilia RSV4 | 2019 Speed Triple RS |
Appreciate
0
|
08-24-2012, 01:10 PM | #87 | |
Brigadier General
101
Rep 3,246
Posts |
Quote:
__________________
mods: track ready stuff
|
|
Appreciate
0
|
08-24-2012, 01:13 PM | #88 | ||
Brigadier General
101
Rep 3,246
Posts |
Quote:
__________________
mods: track ready stuff
|
||
Appreciate
0
|
Post Reply |
Bookmarks |
|
|