Being a GM enthusiast, there is no doubt that you have been exposed to the buzz going on about the upcoming 2008 updates to the base model Corvette. With the 1997 introduction of the LSX-series engines, GM has continued to raise the bar every few years when it didn't seem possible to do so. The 5.7L LS1 debuted with a rating of 345 hp. Then along came the 6.0L LS2 in 2005 to bring the Corvette 400 hp under the hood. For 2008, we now have the new 6.2L LS3 engine: SAE rated to 436 hp and 428 lb-ft of torque! This provides enough motivation for the 2008 Corvette to reach 190-mph top speeds, which makes it the fastest base-model Corvette ever produced.
Short-Block
The LS3 is still considered the GM Generation IV architecture small-block, and it shows a nice progression from the LS2, which it replaces. The new engine block is the same as the 6.2L L92 aluminum blocks found in the 2007 Escalade and Denali trucks. It has the typical cast-in iron cylinder sleeves, but the bore diameter has increased from the previous LS2's 4.00 inches up to 4.06 inches, which results in a displacement increase from 6.0 L to 6.2 L. Some casting and machining updates were made with the LS3/L92 block, resulting in 20 percent stronger bulkheads inside. It is interesting to note that all of the base model Corvette LSX engines have shared the same crankshaft stroke of 3.62 inches, and this remains with the LS3. By using some simple hot-rodder math, readers have probably figured out that these 4.06-inch cylinder bores can be used to build some relatively inexpensive 414ci stroker engines by just swapping in a 4.00-inch rotating assembly. Looking back in the LSX world a few years ago, it would have required costly resleeving of the 3.90-inch bore LS1 blocks to achieve displacements beyond 382 ci. Needless to say, the GM performance aftermarket loves the parts GM now offers over the counter.
Inside of the block, we find newly designed flat-top pistons with coated side skirts. These hypereutectic cast-aluminum pistons help bring the compression ratio to a pump-gas-friendly 10.7:1. The piston oil control rings have revised tension to handle the higher 6,600 rpm redline. Even the piston profile and pin bore were revised to reduce engine noise and vibration. The pistons use a new pin that is taper-bored to reduce mass. At the big end of the connecting rods, the bolts have been upgraded to 12.9-grade material, similar to what is used in the 505hp LS7.
 |  An internal view of the crankcase...  An internal view of the crankcase shows newly revised areas that have been reinforced and machined in order to increase structural strength of the bulkheads. |  The foundation for the LS3...  The foundation for the LS3 is this all-aluminum block with cast-in-place cylinder liners. Bore diameter has increased from 4.00 inches to 4.06 inches, resulting in a displacement gain from 6.0 L to 6.2 L. This block is also used for the L92 truck engines. |