3 ms·

> A factory can ensure precision and consistency at a level that those hand crafting things never could. Idk, in the example "a built racecar engine" one coul

> A factory can ensure precision and consistency at a level that those hand crafting things never could. Idk, in the example "a built racecar engine" one could imagine that instead of running CNC machines all day long to make pistons, replacing tools for wear periodically, a machinist could take a brand new end mill, make some initial test cuts and validate the dimensions, then make the final part and look it all over with the CMM or other tools. You could, by paying extra attention to each part, make a more precise part than something being made on an assembly line where things are not double checked quite so meticulously, for basic efficiency reasons. Like I assume that by the same definition of "hand made" as the racecar engine, we would consider NASA rovers to be hand made. And they are made to a very high precision. We could consider whether SpaceX Engines have ever been "hand made" and how the quality of those relates to production engines (tho in this case, production engines must have rigorous validation of basically every component I would imagine, so the factory perhaps meets or could even exceed hand production runs in quality). But I would not say it needs to be a hard and fast rule.

ryao 2y ago
I suspect the original author’s use of “a built racing engine” was a bad example since there is no factory line for such things as they are too low volume. However, if we loosen the definition of racing engine to include hot rods, then I believe proven factory built designs are highly valued. To give one example: > The 2JZ-GTE, which sits in the heart of the Supra, is one of the best inline-six out of Japan and easily tunable to 500+ Hp on stock internals. https://www.drifted.com/1gz-fe/ https://www.drifted.com/1gz-fe/
- spaceguillotine 2y ago
  here is the website that proves your statement as incorrect, Ford will even sell you a track ready mustang if you want it. https://performanceparts.ford.com/engines/ https://performanceparts.ford.com/engines/
  - deleted 2y ago
    [deleted]
  - deleted 2y ago
    [deleted]
  - ryao 2y ago
    You might have had me convinced, but then you mentioned a Mustang, which is not a race car. Now I am skeptical. Are any of these engines used in NASCAR, F1 or any professional autosports? If not, they are not “racing engines”. By the way, for very low volume parts, it would make sense to make them by hand, so just because Ford lists them does not mean that they are made on an factory assembly line. That is if they are actual engines used in professional autosports. If they are hot rod engines, a factory production line would make sense since those have a bigger market.
kragen 2y ago
It seems like you're comparing a tight-tolerance handmade part with a loose-tolerance mass-produced part. But it's possible to mass-produce parts to any desired level of tolerance. It just costs more. TSMC is currently mass-producing parts with tolerances on the order of a nanometer. It also costs more to handmake parts with tight tolerances than to handmake them with loose tolerances. So from a certain point of view tolerances are all about your budget. Here's the crucial part, though. You can get any given tolerance level more cheaply by handmaking things at low volumes, and more cheaply through mass production at high volumes. But let's talk about consistency. In today's statistical process control regimes, it's common for mass-produced parts to hit "six sigma": the point where the tolerances they're manufactured to are six standard deviations out from the process mean, so the normal variation in the process will only produce out-of-tolerance parts in one of a billion cases (1 - pnorm(6) in R). In practice, uncharacterized sources of variation that don't follow the normal distribution tend to overwhelm that, but it's still common to have a better than 99% chance that the part the manufacturer sends you will meet its specifications. By contrast, when you contract with someone to make the first instance of something, if it's a very reputable maker, you might get 95%. The other 5% includes things like misunderstandings of the specs, unforeseen accidents, and undetected sources of deviation. In complex fields like architecture and software your chances of getting what you ordered are more like 0%.

ryao 2y ago

I suspect the original author’s use of “a built racing engine” was a bad example since there is no factory line for such things as they are too low volume. However, if we loosen the definition of racing engine to include hot rods, then I believe proven factory built designs are highly valued. To give one example: > The 2JZ-GTE, which sits in the heart of the Supra, is one of the best inline-six out of Japan and easily tunable to 500+ Hp on stock internals. https://www.drifted.com/1gz-fe/ https://www.drifted.com/1gz-fe/

spaceguillotine 2y ago
here is the website that proves your statement as incorrect, Ford will even sell you a track ready mustang if you want it. https://performanceparts.ford.com/engines/ https://performanceparts.ford.com/engines/
- deleted 2y ago
  [deleted]
- deleted 2y ago
  [deleted]
- ryao 2y ago
  You might have had me convinced, but then you mentioned a Mustang, which is not a race car. Now I am skeptical. Are any of these engines used in NASCAR, F1 or any professional autosports? If not, they are not “racing engines”. By the way, for very low volume parts, it would make sense to make them by hand, so just because Ford lists them does not mean that they are made on an factory assembly line. That is if they are actual engines used in professional autosports. If they are hot rod engines, a factory production line would make sense since those have a bigger market.

kragen 2y ago

It seems like you're comparing a tight-tolerance handmade part with a loose-tolerance mass-produced part. But it's possible to mass-produce parts to any desired level of tolerance. It just costs more. TSMC is currently mass-producing parts with tolerances on the order of a nanometer. It also costs more to handmake parts with tight tolerances than to handmake them with loose tolerances. So from a certain point of view tolerances are all about your budget. Here's the crucial part, though. You can get any given tolerance level more cheaply by handmaking things at low volumes, and more cheaply through mass production at high volumes. But let's talk about consistency. In today's statistical process control regimes, it's common for mass-produced parts to hit "six sigma": the point where the tolerances they're manufactured to are six standard deviations out from the process mean, so the normal variation in the process will only produce out-of-tolerance parts in one of a billion cases (1 - pnorm(6) in R). In practice, uncharacterized sources of variation that don't follow the normal distribution tend to overwhelm that, but it's still common to have a better than 99% chance that the part the manufacturer sends you will meet its specifications. By contrast, when you contract with someone to make the first instance of something, if it's a very reputable maker, you might get 95%. The other 5% includes things like misunderstandings of the specs, unforeseen accidents, and undetected sources of deviation. In complex fields like architecture and software your chances of getting what you ordered are more like 0%.