LarryMJones

I have often heard the term hand assembled refering to the LS7 Z 06 engine.

I watched the National Geographic special and noticed several of the assembly steps were automated. For example a machine torqued down all the head bolts at one time. I had envisioned a master engine builder carefully torqueing down the head bolts, one at a time in the correct order with a precision torque wrench.

How many people hand build engines with impact wrenches?

LJ

nwc6

Those are not exactly "impact wrenches"..I did a quick google and found a couple of pneumatic torque wrenches that had accuracy of +/-3% ..And this was a range of 50-5000ft/lbs..Using those wrenches the repeatable accuracy of the bolt torque is probably far better than it would be using a manual wrench..
Welcome to the 21 century..

AORoads

I'd have to agree that all hand built is probably not even the best thing today, nor is it the definition of "hand built" in most cases.

In a way, just try to imagine laser-cutting something like sheet metal vs. "eyeballing" it after a line is drawn on the piece. I'd say, no comparison in repeatable degree of accuracy.

But you could still take the two laser-cut pieces of metal afterwards and screw them into something by hand and call it "hand built." In most instances, I know which two pieces I'd rather have.

ohmy

The LS3 in manual GS models is also supposedly hand built...

I have no idea why it would be so for manuals and not automatics ( but I think bc of the dry sump )...

I don't think hand built is better in any way than the mass production way... I think it's just a matter of investing in machines vs investing in people - for huge volume it would make sense to invest in machines, otherwise low volumes are probably cheaper with people... but I'm guessing here, if anyone wants to correct my theory please do...

GSRANDY

The Z16 GS coupe with the MN-6 transmission LS3 engine is in fact hand assembled in the Wixom facility, including the dry sump oiling system.

By the way the engine also includes a forged steel (greater strength) crankshaft as opposed to cast iron.

Regards,

GSRANDY

nwc6

Good thread here:http://forums.corvetteforum.com/c6-c...lder-tags.html
What it gets the consumer is simply higher quality control, or at least more quality control steps.

EDinPA

you don't need an 'order' when you do all exactly equal at exactly the same time.

Shortimer

GM has been "hand building" engines for a very long time. I am the original owner of a 1976 Cosworth Vega and its engine was hand-built at the Tonawanda plant in NY. There is a sticker on the cam cover where the builder signed his name.

eaglei

We do not build engines with impact wrenches. The only time an impact wrench is used is for removal of main caps (before setting crankshaft).

We do use precision electronic torque wrenches, which are computer controlled. Spindle speed, initial torque and final angle are applied as specified by engineering specs. Using a clicker wrench would not give a better result.

True, head bolts are torqued simultaneously. This is actually a good thing - the result is a more uniform clampload.

eaglei

If you are interested in seeing how your engines are built at Wixom PBC check out this link. It covers an LS9 build with a writer from Jalopnik.com. Article is very recent.

http://jalopnik.com/5371569//gallery/?selectedImage=55

Thanks for your interest!

Don