The bottom line on the LS6 for 2002 is: it’s one of the two most powerful production V8s ever put in a GM vehicle. Not only that, it meets current exhaust emissions standards, gets great gas mileage and has outstanding drivability. It’s also the most efficient with a specific output of 1.170 horsepower-per-cubic-inch. The previous efficiencty champ in a Corvette was the LT5, used in’93-’95 ZR-1s, at 1.157. Designed in the late-’80s, the 350 cuin. LT5 needed dual-overhead cams and four-valves per cylinder to make that kind of power. The LS6 is just a tiny bit better in specific output using only one cam, pushrods, two valves-per-cylinder and slightly less displacement. Such is how far the march of technology has come in a decade. The LT5 was then and the LS6 is now, but what’s coming next?

People are talking about "C6," the Corvette platform revision due in 2005. This will be an evolution of the C5 rather than the revolutionary step C5 was past the ’84-’96, "C4". The ’05 Corvette also should bring us the passenger car version of the Fourth Generation, Small-Block V8, which will be, of course, an evolution of the current 5.7-liter Gen III. The Gen IV will continue with pushrod valve gear along with other basic architecture features laid down in the Gen III. We think GM Powertrain will use the debut of C6 to enlarge the base engine to six-liters with the horsepower at about 400. With current Corvette marketing philosophy calling for a two-tiered engine offering, there also has to be a "high-performance" engine. We’re betting that’ll be a slightly larger displacement unit generating perhaps as much as 450hp.

We think the challenge in getting 430hp, 390-cid and 400hp, 366-cid V8s past the Feds’ Corporate Average Fuel Economy (CAFE) standards might be a bit of a reach even with direct injection and variable-timed DIBC. How might GM achieve those power levels yet avoid the gas guzzler tax? These new Corvette powerplants are good candidates for the so-called "Displacement on Demand" system GM is developing and has stated it will introduce in some 2004 light-truck applications. "DoD" allows a V8 to run as a V4 in certain light-load duty-cycles. Idaho Corvette Page staff members have driven a prototype, Vortec 5300-powered, 2001 GMC Sierra pick-up with this technology and it’s so seamless, there had to be a light on the dashboard to tell us the engine had switched from eight to four cylinders. With the Vortec 5300 equipped with Displacement-on-Demand in a pick-up, there’s an 8% increase in fuel economy when it’s run through the Federal Test Procedure (FTP) and up to a 25% increase depending on vehicle platform and driving conditions. Increases like that could be the just what the doctor ordered for a 6.4-liter, 450hp, CAFE-compliant, 2006 Z06.

Big-bore, high-tech motor in the ’06 Corvette? Good chance. Let’s see what happens in about three years.