corvettes of fresno - Description: Description: Description ...

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Each engine stand has a clipboard with a build sheet and bar code on it (above). This same bar code is also applied to the engine. Prior to each assembly operation, the bar code is scanned and each torquing operation is logged in a central computer. Multi-spindle guns are used for operations like torqueing the main bearings, and all of the torque guns use electric drive and incorporate torque sensors. To ensure accurate and reliable bolt torquing, the process has evolved in recent years. Way back when, you would use a torque wrench and tighten a bolt until you hit the required threshold. However, that was found to give inconsistent results when tested because of internal differences in the fasteners and fits between the threads. Because fasteners stretch, what they do now is actually over-torque the bolt slightly and then back it off to the required setting. A work instruction sheet at each station lists the operations in sequence with a bar code associated with each. After scanning the engine code, the code for the operation is scanned. When the sensors have detected the operation has been completed and the bolts are properly tight, the gun automatically shuts down to prevent over-torquing. The system keeps track of all the data related to each build so that if any problem is detected during the final test or inspection, the whole process can be reviewed. Anyone who has ever put together an engine (properly, of course) knows that you have to torque the bolts in a particular order to avoid damaging warpage. The multi-spindle gun for the main bearings on the LS9 does the four vertical bolts on one cap together. Starting from the center of the crank you work your way outward alternating front to back. After each cap is tightened, we turn the crank a couple of times to make sure that the resistance hasn't suddenly increased dramatically. If it suddenly becomes much harder to spin the crank, you know something is wrong and can go back and fix it before getting too far along in the build. Once the crank is all tightened up, it's time to install the pistons. The block is rotated on the stand and everything is lubed up prior to insertion. Again the crank is turned to ensure that nothing is hanging up. This is followed by the oil pan, timing chain, oil pump and the rest of the bottom end. The oil passages of the pan and pump are checked before installation to make sure that no parts or chips got in there to block oil flow, something that's especially important for a high performance engine such as the LS9. In fact, throughout the build process, everything is checked and double checked to make sure the engine is right before it gets to the cold test at the end. Once the bottom end is buttoned up, the LS9 turned right side up again to install the cylinder heads. Because of the high pressures generated inside the supercharged LS9, GM went with seven-layer head gaskets and larger 12 mm bolts to keep the cylinders sealed tight. After the lifters, push-rods and rockers are installed it's time for the supercharger. General Motors classifies the surfaces of all parts of a car as 1, 2 or 3. Class 3 surfaces are those that are never actually visible to the customer, like the back side of the dashboard. Class 1 surfaces are visible like the body panels and care must be taken to make sure they don't have any scratches or other blemishes. Among all GM engines, the only class 1 surface is the LS9 intercooler cover because it's visible through the hood window. The supercharger and intercooler come into the PBC already assembled as a unit. Once we bolt it into the valley, a cardboard cover is placed on top to make sure it doesn't get scratched. With the blower in place, it's time to check the LS9 for leaks. Hoses are hooked up to all of the external connections and both positive and negative pressure are applied to the engine for a couple of minutes. Thankfully our LS9 passed the leak test with flying colors.
Once an engine passes the leak test, it's time for the builder to apply his name tag. Since we were only a temp at PBC, you won't find any LS9 engines with an Autoblog logo on them. However, if you buy a 2010 ZR1 and find a plaque with Mike Armstrong's name on the side of the intercooler, it could well be the one we helped put together. At the final station we hook up the engine lift and unbolt the power-plant from the build stand. Once the engine is free, we can complete the last step of the assembly process, which is the installation of the flywheel and dual plate clutch. The LS9 gets a 260 mm-diameter clutch with two plates that allows for a lower effort to disengage and less inertia than a larger single plate unit. That all helps to make the ZR1 much more drivable in the real world. From the assembly loop, the engines head over to the cold test and balancer stands. On the cold test stand, the engine is spun up electrically to check items like the compression, water pump, oil pump, etc. On the balance stand, the fuel line is connected for the first time and exhaust pipes are clamped onto the headers. The engine is fired up and run briefly on natural gas to check for vibrations caused by weight imbalances. If necessary, weights are added to the front crank damper and the flywheel to smooth things out. Once the vibrations have been negated, the engines go through a final visual inspection before being loaded on racks and getting trucked south to Bowling Green for installation into new Corvettes. We want to thank Mike Armstrong for his patience in answering our questions and guiding us through the build process at PBC. After seeing how the LS3, LS7 and LS9 are built at the Wixom Performance Build Center, we have even more respect for these high-end Corvettes. Going into the 2010 American Le Mans Series, the GT2 Corvette C6.R will be switching from its current 6.0-liter V8 to a new 5.5-liter unit based on the next generation small block. Last summer Corvette Racing manager Doug Fehan revealed that these new GT2 engines would be built in Wixom right alongside the road going engines, a major coup for the staff there. Congratulations to them and keep up the great work.
Page 2 and 3: CORVETTES OF FRESNO, INC Is a non-p
Page 4 and 5: Membership Corvettes of Fresno has
Page 6 and 7: March 13 th Saturday 12 noon Americ
Page 8: ICE BREAKER SAT. FEB 20 TH 2010 Wel
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Page 18 and 19: Wendell Strode Meet The Executive D
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Page 22 and 23: LOT # 2010 Barrett-Jackson Corvette
Page 24 and 25: 1263.1 1966 CORVETTE CONVERTIBLE 42
Page 28 and 29: Collard Joins Corvette Racing as En
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Page 32 and 33: o Fluid Levels Make sure to top off
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Page 38 and 39: January 2010 Corvette Sales The fir
Page 40 and 41: The new ZR1 also uses supercharging
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Page 44 and 45: VINTAGE 1960 CORVETTE POSTER AC SPA
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Page 51 and 52: GM: Next-Generation Corvette C7 Exp
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Page 59: P.O. BOX 26223 FRESNO, CA. 93729-62

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