rikhek

Serious question: Why would a hand built engine be preferred to a machine built. I'd MUCH rather have a machine built as machines are much more consistent and accurate. People often have bad days, are tired, sick or sometimes just don't really care.

I've never understood this as in my line of work we often have pretty bad things happen due to a persons improper actions or failure to follow procedures. Machine don't make "bad" decisions or deviate from procedures provided accuracy controls are in place and monitored.

Hoping someone can educate me.

Rick

ronsc1985

To eliminate tolerance stacking. If truly hand built, as in hand built race engine, assembled clearances are checked. If hand built is just bolting parts together then there is no advantage.

badhabit_wb

I seriously doubt they do anything special. I would think from a consistency standpoint machine built would be at least as good. Even the "hand built" ones use the machines for a lot of the assembly.

Kracka

It would be interesting to see a failure rate comparisons of the LT4 engines. Regardless, both are likely extremely low in frequency. I definitely think a lot of it is the "cool factor" of there being a builder's name plaque on your engine.

mdz06vetter

Low volume specialized engines tend to be hand built because they're not really making that many motors to make it worth it to build a fully automatic assembly line for the motor. So for a motor you're going to be building 500,000 of it's worth the investment into a fully automated setup, but for low volume vehicles like a lot of high performance versions of vehicles the engines end up being hand assembled because they're not making that many and it's much cheaper to train people to build them than to go build a whole automated factory just to build 1000 motors.

Most cars will use a combination of machine and hand assembly though, there's just some stuff that's currently easier/cheaper to get a human to do instead of paying for a really complicated robot to do. There's also some cars that are almost all hand assembled that are cheap cars (a bunch of lower volume Chinese manufacturers use heavily human dependent assembly lines) and it definitely doesn't mean that they're better than machine assembled ones.

There's a lot of marketing going on too, when Nissan puts out a video about people hand building the GT-R motors they're using the whole "using master technicians" thing as a marketing exercise. People like to hear that the stuff they're buying was hand crafted using many hours of effort because it helps them feel nice about what the bought. Knowing that it was precision made by a machine that did it in a 1/10th the time a human would doesn't make you feel particularly nice inside but practically speaking it's probably even more consistent in quality than a human would be.

sunsalem

You guys all make great points.
The "hand-built" thing is important for wood furniture, but not for assembling an engine.
The first time I heard it was from MB's AMG division.

3 Z06ZR1

I thought they are all the same now? They all get a hand built tag!

3 Z06ZR1

Did they check every clearance? I maybe wrong but not in the little bit I have seen. More putting parts together.

rikhek

I personally would pay extra to ensure for a machine built engine rather than hand built. Not a dig at the builders, but a nod to the tight tolerances obtained with current machine manufacturing methodology.

If I were in charge of GM marketing I wouldn't divulge the fact that ?some? engines are built by hand.

Sort of like the manual versus auto argument. No way ANY human can shift as fast a a current performance automatic trans.

Rick

rikhek

I'm either confused by your posts or just missing the point you're making.

Your first post "cheers" the fact that they're hand built and come with a tag showing who built it.

Your second post correctly critical pointing out they do very little, if any checking of tolerances and they just bolt parts together.

Which is it? I personally am not impressed by what I consider to be a "silly" little tag showing the name of the person who bolted it together....

GMHZ06

I did the LT4 engine experience for my 2017 Z06 and can tell you the human eye, feel and inspection process is better than any machine. The engine parts come in to the factory and are put on a pile. The engine builder will inspect, feel even move the part prior to installation, the machine will simply take the first part and install it. We didn't use the first mega-lifter as my builder found in not smooth enough so we picked another and installed the better one instead. Small imperfections can be hard to see/notice so the human is better in that situation.
I like hand made because that makes it special. My refrigerator can be made by a machine.

Mr. Gizmo

One thought which may need to be considered. your builder might have been a shill and that is part of the General Motors act to make you feel good about paying the premium for the build experience

https://en.m.wikipedia.org/wiki/Shill

Bill Dearborn

Rick,
I agree. Humans are very error prone no matter how well they check things or how many times they check things. The hand built Corvette engines are built using basically the identical tools the engine assembly plant uses. That way they can control the quality of the build. The big difference is one person assembles the engine Vs several on a line. You may notice the person doing the engine assembly doesn't assemble the pistons on the rods. They are more than likely delivered from the supplier that way. If you purchase rods from GM they come with the pistons installed.

Bill

GMHZ06

Wow that is funny. Are you a conspiracy theorists. Please go through the experience first then your view will be different. GM losses money doing this kind of thing. They have a complete production line waiting for customers to do it. Line 1 sits idle. The other two identical lines are with the other engine builders making 2.5 engines a day. The cost alone to duplicate a full production line for some 32 people for 2017 MY doesn't seem efficient. All the extra validation needed to be sure the novice does things correctly takes time away form production. I took 9 hours that day in what normally takes that same builder half that but he didn't have an inquisitive party asking and learning the process throughout the build. It is called an experience because that is what you do with very well experienced hand assemblers. No Shill required.

C5-VERT

Rebecca built my engine, and we all know women are more meticulous than men or some stupid machine!

silver74vette

I'm pretty sure that all of the engines are assembled by hand, some are just on a line and go from one person to the next and some are assembled by one individual. My vote would be for a single individual as they are probably selected due to experience and ability.

dmaxx3500

about $7,000.oo to help hand build it at plant

383vett

Handbuilt Ferrari motors can buzz to 9000. Try that in a Chebby.

dollarbill

Ha ha. Most of that is in the engine design and parts tollarances. You won’t find many pushrod V8’s in those F cars.

z51vett

The techs assemble and inspect parts machines are used to tighten all fasteners.
All specs are recorded and kept for reference.
z51vett
Doug