One man, one engine ... people are sold

[swamp2]

Originally Posted by BMRLVR

I have no doubt that cost is always a factor, however, at a production rate of about 100 engines per day, there is time to have extra QC and be tighter on tolerances.

...

One thing I do have knowledge of is engine assembly, and I can safely tell you that I have seen many mass produced engines from automated assembly lines that have issues from either improper clearances, defective parts or incorrect assembly (gaskets or o-rings left out). I have no doubt that machines are able to make perfect engines provided that every bore, part, fastener, etc. are of perfect dimension and free of defects, however at extremely high volumes I don't think manufacturers are inspecting every part for quality or dimension, they are probably only inspecting every 100th or 1000th part. This less than 100% QC is the main reason for recalls, and manufacturers warranties, to deal with the inevitable problems that get past the machines.

I am still confident that an engine that is hand assembled by a craftsman who is verifying every measurement with a hands on nature is going to be built tighter compared to an engine that is built by a machine where maybe every 100th engine is pulled from the production and inspected. I may be wrong on this but this is my feeling. I also think that if BMW were hand assembling the S54 and S65 blocks that they wouldn't have had the main bearing issues that seem to be cropping up because they would have had the oil clearance adjusted to the proper specs instead of trusting in mass produced parts that may be off 0.0005" here and 0.00025" there causing issues down the road!

Mostly agree here. There can be both good and bad hand assembly and machine assembly. It actually comes down to both quality assurance and engineering - the actual design. Engineers are responsible for setting tolerances on each part. The balance is on cost vs. engineering function. Obviously some dimensions are way more critical than other, again here main bearing clearances and piston-bore clearance being tight whereas something like a bearing width or total camshaft length is not nearly as critical. Problems arising from these values not being proper to insure good and long engine function can be design, manufacturing or inspection. Certainly more critical dimensions receive more scrutiny in each domain. I'm not up on the details of the SPC (statistical process control) of engine block and internals machining. I am pretty confident though that on critical parts such as these, contributing to these kinds of high precision fit requirements, 100% in line inspection is occurring. Again machines can do this extremely fast and extremely inexpensively.

I've never argued that all machine built engines are superior. Only that given the choice for a high production volume engine, I would place my bets (and personal buying choice if I actually had one...) on the machines for the vast majority of the process. Even in the case of hand assembly, the vast majority of the part production and inspection is still likely done by machine (I guess that is obvious to many but still worth stating again). As discussed prior, we can eliminate the human from the line but for any reasonably high volume we can not eliminate the machines. Bringing it full circle faults due to machines are ultimately problems with the human team behind the machines themselves (again could be design, QC, inspection, maintenance, etc.).

It would indeed be fascinating to see a video like the one above of the 3er main assembly for engines, comparing something like the Honda Accord (very high volume) to something the the M156 (AMG Engine - mass produced but much smaller volumes).

[BMRLVR]

Originally Posted by swamp2

Mostly agree here. There can be both good and bad hand assembly and machine assembly. It actually comes down to both quality assurance and engineering - the actual design. Engineers are responsible for setting tolerances on each part. The balance is on cost vs. engineering function. Obviously some dimensions are way more critical than other, again here main bearing clearances and piston-bore clearance being tight whereas something like a bearing width or total camshaft length is not nearly as critical. Problems arising from these values not being proper to insure good and long engine function can be design, manufacturing or inspection. Certainly more critical dimensions receive more scrutiny in each domain. I'm not up on the details of the SPC (statistical process control) of engine block and internals machining. I am pretty confident though that on critical parts such as these, contributing to these kinds of high precision fit requirements, 100% in line inspection is occurring. Again machines can do this extremely fast and extremely inexpensively.

I've never argued that all machine built engines are superior. Only that given the choice for a high production volume engine, I would place my bets (and personal buying choice if I actually had one...) on the machines for the vast majority of the process. Even in the case of hand assembly, the vast majority of the part production and inspection is still likely done by machine (I guess that is obvious to many but still worth stating again). As discussed prior, we can eliminate the human from the line but for any reasonably high volume we can not eliminate the machines. Bringing it full circle faults due to machines are ultimately problems with the human team behind the machines themselves (again could be design, QC, inspection, maintenance, etc.).

It would indeed be fascinating to see a video like the one above of the 3er main assembly for engines, comparing something like the Honda Accord (very high volume) to something the the M156 (AMG Engine - mass produced but much smaller volumes).

Mostly in agreement with you on all the above points and always enjoy our exchanges on here!!!

[gthal]

I have determined that everyone on this thread is smarter than me because I haven't been able to follow any of this since post #10

[klammer]

It's just a matter of time... Sky net will become self aware, I fight for the humans!!! :

[bimmerj]

[clar]

They used machine to apply the sealant, not hand applied. Cheaters!!!

[bruce.augenstein@comcast.]

Originally Posted by bimmerj

I notice they didn't speak in any way about custom-fitting of pistons.

Hmm.

[swamp2]

Good video. Good ol' reliable Youtube.

Seems pretty clear from the video that it is completely fair to say the engine is hand assembled. The only thing computers are doing is sealants, torquing, component tracking and data collection (of course as well as 99%+ of the component production...). Again based on the relatively low volume of engines being produced this is THE least expensive way to build these engines. MB is absolutely taking advantage of this necessity (not choice) and appealing to the race engine/hot rodding/magic of the human hands angles to market the hand built "feature". If these engines were made in substantially higher volumes they WOULD be made faster, more precisely and at a lower cost by moving away from hand built to robot/machine/computer built.

[swamp2]

Originally Posted by bruce.augenstein@comcast.

I notice they didn't speak in any way about custom-fitting of pistons.

Of course not, it is too expensive!

[Mueller944s2]

Here's how I see it. On an assembly line (BMW, Porsche, Ferrari) everyone does the same task over and over every day, they know that job inside, outside, and upside down, heck they probably dream about it! If you have one person building the whole thing (apparently AMG) with no division of labor you don't have specialization. I'm sure the AMG guys are good, but I'd rather have 10 people specializing in their small individual tasks than 1 person building the whole thing.

[swamp2]

Originally Posted by Mueller944s2

... I'd rather have 10 people specializing in their small individual tasks than 1 person building the whole thing.

Very good point. That probably would increase speed, efficiency and result in higher quality. It may be balancing potential boredom vs. efficiency though.

[bruce.augenstein@comcast.]

Originally Posted by swamp2

Of course not, it is too expensive!

Several people in this forum have already corrected me and explained that it would not be particularly expensive to measure and keep track of piston sizes, and offer them up as each cylinder is precision measured.

[swamp2]

Originally Posted by bruce.augenstein@comcast.

Several people in this forum have already corrected me and explained that it would not be particularly expensive to measure and keep track of piston sizes, and offer them up as each cylinder is precision measured.

I suppose it is relative, it would certainly add time and cost. Exactly how much is largely speculative by the vast majority of folks here on this forum. MB either decided it was too expensive, did not offer benefits based on the existing precision of their parts or some combination of cost/benefit was not high enough.

[kwike92]

Originally Posted by Nine

Some people take pride in the weirdest things, I don't go around telling people their wives are really ugly, let him enjoy his prize, sometimes you just have to let these things go.

how ugly their wife is...bahahahahahaa:lol :

[krnnerdboy]

Off tangent but on parallel that many can relate with...

In the watch world many will pay(myself included) a huge premium to have an in house movement over an eta movement. Absurd? Sort of considering a Casio g shock is about as accurate as a watch can get. People find value in different things.

[swamp2]

Originally Posted by krnnerdboy

Off tangent but on parallel that many can relate with...

In the watch world many will pay(myself included) a huge premium to have an in house movement over an eta movement. Absurd? Sort of considering a Casio g shock is about as accurate as a watch can get. People find value in different things.

Very good analogy/counterpart to this discussion. I think quite a few folks here like watches (and/or even have a small addiction..). Not a bug I ever caught myself, but I know I have leanings that could get me engulfed in this area of interest.

In this specific case though wouldn't both the fundamental manufacturing and assembly techniques be nearly identical? Or do some of the smaller movement manufacturers do all hand assembly vs. machine assembly by ETA? Sort of like an engine though I would image hand made components are also basically non-existent. If this is the case then it appears you are paying only for rarity or brand. Nothing essentially wrong with either but personally I would place more intrinsic value in rarity. Similarly with accuracy - some would claim that nothing trumps accuracy for an item like a watch but there certainly are many reasons to covet and value watches with much less accuracy than a Casio.

[BMRLVR]

Originally Posted by bruce.augenstein@comcast.

Several people in this forum have already corrected me and explained that it would not be particularly expensive to measure and keep track of piston sizes, and offer them up as each cylinder is precision measured.

Originally Posted by swamp2

I suppose it is relative, it would certainly add time and cost. Exactly how much is largely speculative by the vast majority of folks here on this forum. MB either decided it was too expensive, did not offer benefits based on the existing precision of their parts or some combination of cost/benefit was not high enough.

It is possible that blocks and pistons are picked as sets that are pre-matched.

Notice that the connecting rod on the cap has a 2D bar code on it. That bar code can contain lots of information that "MAY" be used to ensure the pistons, rods, crank and blocks are picked in a matched set........ Or........ it could just be a part number.

[bruce.augenstein@comcast.]

Originally Posted by BMRLVR

It is possible that blocks and pistons are picked as sets that are pre-matched.

Notice that the connecting rod on the cap has a 2D bar code on it. That bar code can contain lots of information that "MAY" be used to ensure the pistons, rods, crank and blocks are picked in a matched set........ Or........ it could just be a part number.

At a guess, if Mercedes was actually matching pistons with individual cylinders, they'd say so.

On the other hand, mentioning that sort of activity essentially declares that there are variations in the manufacturing/machining processes, which might make a casual viewer wonder about quality control.

That settles it. Swamp has to go visit the plant and bring back The Truth!

Bruce

[swamp2]

Originally Posted by BMRLVR

Notice that the connecting rod on the cap has a 2D bar code on it. That bar code can contain lots of information that "MAY" be used to ensure the pistons, rods, crank and blocks are picked in a matched set........ Or........ it could just be a part number.

I saw that QR code on the rod and thought it was interesting. It can indeed contain quite a lot of data. I actually suspect it is being used precisely to store more information than just a part number. A regular bar code would be fine for just a part number that thus making a QR going overboard. My speculation though it that it does not contain individualized dimensional information.