sgd1201

It is my understanding that because the Grand Sport with Manual Transmission has the Dry Sump Oil System, and a differential cooler, this is the reason the engine is "hand" built.

What are the advantages (if any) of the hand built LS3 vs the LS3 that goes through the assembly line?

Torchsport

Both are hand built. Dry sump motors are build by one tech. The others are hand built by a team.

I'm sure they are both quality builds.
As you said, the dry sump is the main advantage, IF that's what you need/want.
That's what I have.

sgd1201

That's why I put hand in quotes...... I have seen it referred that way in some articles.... I was aware of the single tech vs the team. But thanks for the clarification....

Also curious why does the dry sump and differential cooler cause the engine to be built by one tech in one station. Or is this not the reason the GS engines are built this way?

Z06LUST

MARKETING.
NO difference in engine quality, durability, hp-PERIOD.
Z06 (LS7) Production is way down....gives work to engine line..
Dry sump is helpful if you are into Tracking (twisties) on tracks with LONG high g load corners....

Otherwise it is a marketing angle to highlight the 'track potential' of the manual GS.

Per GM engineers (Tag) the auto tranny cannot stand has high of a continued G load force thus the higher ability of the dry sump suystem in not needed in auto versions as it is not recommended for extreme track use. There is a presentation on Youtube in which Tag talks about the manual/auto needs in terms of handling extreme lateral loads.

This is not "new" as to the auto versions getting "less"...the "Old Z51 option only came with coolers on the manual version, not auto.

rayk

Dry sump engines are built here. They require a different crank.

http://www.gmpowertrain.com/pbc/

sgd1201

Thanks for the link..... I had not seen that website yet.... I like it!

Raazor

Mach2

As a side note, there's been a number of us 2008 (LS3) and newer owners that have had issues with the oil pan leaking, and it's been talked about alot here on the forum. I don't recall reading about a single, one man built, LS3 (6 speed stick dry sump) or LS7 with this oil pan leak issue.

MikeyTX

You get to spend more money for an oil change if that's an advantage.

tim414

The "hand-build" is simply for marketing. That's it. These engines are no better than the assembly line builds. When it started it was only LS7's built there (PBC). With the economy tanking and adding LS9 to Vette's line-up, LS3's (with std tranny/coupe only GS) were added. And as someone else stated I believe only crank is different on any.

The dry sump oiling is for sustained banked high G-loads to prevent oil starvation on the engine. Otherwise, the only thing it's good for is higher oil change cost .....

This has been a topic many-many times on this forum. The hand build thing is only for the marketing dept at Chevy/Corvette. (but it was effective at getting "me" to want one )

When C6 Z06 first appeared, granted, it 'was' a big selling point. May be so even today. I suppose that's why they added the engine build experience where you can opt to go to Michigan (Performance Build Center-PBC) and build your LS9 or LS7 and have a plaque on 'your' engine, which will then be shipped to Bowling Green and installed in your ZR1 or Z06. The exoctics are hand built, so this is simply marketing to compete with those cars.....

When Z06 first appeared, it was one of the top performing cars of it's day....(I'm talking about it like it's no longer around-go figure)...since then, other manfacturer's have risen up to equal and surpass Z06....even GM did so with ZR1....

But, the 'Z' model Vettes are still among the fastest cars on the planet, and when cost is figured, their probably ranked in top five.....everything else than can outperform the 'Z' models cost alot more....

If GM had (had) the GS when I bought my first C6, I would have owned one. The wide-bodied Vette is overwhelmingly desired among Vette buyers/owners/enthusiast....that's why GS sales account for over 50% of Vette sales.....and it's funny that folks at GM knew this would happen when they introduced GS.....

So, the dry-sump oiling system along with diff cooler are performace items with their advantage's enjoyed off-road (track)....and not the reason LS3's (GS Coupes/man. tranny) are hand built.

eaglei

Yes the dry sump LS3's use a forged crank with a longer snout to accomodate the longer crank sprocket. The longer sprocket drives the dry sump oil pump which has two gerotors - to pump oil within the engine and to pump through dry sump system.

I do build engines at Wixom, but am not an expert on what goes on at other GM engine plants. So it is hard for me to make comparisons. But you can be assured that we take quality very seriously at Wixom.

Thanks for supporting us! And we'd love to see you post "Who built your dry sump LS3" on that thread of Corvette Forum. Welcome to the club!

laconiajack

"Hand-built" became obsolete back around Civil War times with mass produced weapons having interchangeable components, and especially so for automobiles with the advent of the model "T" Ford. The only reason anything is "hand built" today is that the volume of production doesn't justfy a heavy capital investment in automation.

RO55

Hand-builts would seem the way to go - more pride of builders?

Vegas Panton

Our local Corvette Club just had a Dyno Shootout a couple of weeks ago at Shelby American Motorsports (Dynojet Dyno). One of our members had a 2011 GS 6 spd/dry sump. Untuned it turned out 403 RWHP and 392 TQ. http://www.vegasvettes.com/Events/20.../1112Dyno.html Most of the LS3 manual transmission cars (untuned) put out around 390 RWHP on this dyno. As I recall it was running rich like most of the factory tunes. So the question is: Where did the extra HP come from? Dry sump? Hand built? Just one of those exceptional engines? A little bit of all three?

JoesC5

Have you ever seen a robot not tighten a bolt because he was scratching his *** with that hand?

JoesC5

Maybe less tire slippage on the rollers with the larger meats?

Uncle Meat

I agree... and shouldn't we really be referring to this process as "Hand Assembled"?

U.M.

Tom/99

That's not really how I would have said it, but

ospreycorvette

I feel better with hand assembly, machines that push those pistons into the block might not be as careful as hand install. What if the machine is slightly out and forces it, same for other parts.

eaglei

Built vs. assembled? Seems to be a hot button issue for some folks. True that we do not measure all of the parts we use for dimensional accuracy. That is done before shipment to Wixom, and is more efficient. However we do some things that automation does not, such as offsetting ring gaps. In any event our facility is called Performance Build Center and most people call us builders. If you prefer to call us assemblers then so be it.

There have been several discussion threads on the topic of hand-built engines vs. mass produced. The following is a copy of what I previously posted pertaining to this.


I doubt that I can adequately answer all of your questions regarding advantages of our hand built engines. In order to do so I would need comparative data concerning power, reliability, durability and failure rates of mass produced vs. hand built. As an engine builder I do not have conclusive information. All I can do is address questions about our hand built process.

With that in mind, I'll offer some observations from my perspective:

Hand built engines have a higher level of scrutiny. This applies to the inspection of parts before assembly and to examination of complete engines. Parts are closely inspected for imperfections and for cleanliness. Also a builder develops a "feel" for how things should go. If something doesn't feel right, you can immediately verify - or back up if need be. An example of "feel" is inserting pistons into cylinders.

Close inspection is inherent to the process - each part is installed by the same builder - and installation requires a high degree of awareness. That is not to say that all defects are always caught - but we do have some very careful eyes looking things over. An added incentive to careful assembly is that our names are attached to our engines.
If defects are found, or suspected, we have immediate response from our in house quality and engineering teams. If something is questioned, it can be immediately contained until the issue is resolved. Again, I'm no expert regarding what happens at high volume engine plants, but I do know that our close scrutiny has resulted in changes from our suppliers ensuring cleaner parts, and fewer imperfections. Examples include better packaging of cylinder blocks and crankshafts. Our observations and findings put the heat on suppliers to supply consistent, high quality components.

Builder Experience. All of the builders are skilled journeymen with many years of experience at building engines. The vast majority of us previously built engines at GM Engineering labs. We also have experience using inspection equipment as required when producing engines in small batches.

Error proofing:

All torques have multiple checks. When a fastener is tightened there is an immediate go/no go indication. Also each station has a flat line indicator to ensure all torques are complete. Further, the stations are monitored with zone reports. There are four zones for each engine built which give a green (go) or red (no go) indication. When completing a zone, the builder does a bar code scan for his engine to get this output.

Leak checks - each engine is carefully leak checked before completion. Water and oil systems are pressurized and leakage is recorded. Again, there is a green (go) or red (no go) output. If there is a problem it is immediately investigated and fixed. I have been told that our specs. are the strictest for any GM engine plant.

Care checks - Each engine is carefully examined by the team leader at the end of the line, using a comprehensive checklist. After cold test and balance the engine is again checked against an exhaustive checklist.

Cold test - Each engine is spun and checked in house at our cold test cells. Thousands of data points are recorded and scrutinized by the computer program. If a problem is suspected it is immediately caught and examined by our quality specialists. Items checked include ignition, oil pressure, torque variation, cylinder pressure and many more. Cold test has proven to be a valuable quality tool.

Balance checks - After cold test each engine is run and balanced. Balance must be within 0.5 inch ounces at front balancer and flywheel before it is shipped (and is often much less).

Customer focus - We are low volume so every order is very important us. We cannot survive unless our customers (you) are satisfied. We have frequent customer interaction, through the Corvette Forum and other venues.

Tangible value - This is somewhat subjective. Many Z06, ZR1 and Grand Sport owners enjoy knowing who built their engines, and some have come into the PBC for tours and to meet their builder. Our facility is owner friendly - you can easily arrange a tour to see how our process works.

I would like to believe that our product retains a premium dollar value, but that may be harder to verify with the economic turmoil of the last few years.

Sorry if I've danced around some of your questions. I hope this info is of some value to you. I'm sure I've missed some points that should be included. If you have any particular questions, please ask.

Don Henley