In last month’s column, I gazed into the VETTE editorial crystal ball to forecast a few of the features of the next-generation Chevy small-block. Since the official specs on the motor are literally being released as I type this, I’ve decided to circle back and take a look at some of the highlights. We’ll have a full rundown of the new SBC in an upcoming issue, but for now, here’s what you really need to know:
It’s an LT1
While Chevrolet is no stranger to mining its heritage for historically significant nomenclature, the residual bad vibes attending the last LT1 make this decision something of a surprise. Perhaps Chevy is hoping potential buyers will associate the new engine with the original solid-lifter LT-1 of the early ’70s, and not its leaky, glitch-prone successor. Or maybe the company is simply counting on the C7 mill’s dazzling specifications to permanently expunge the word “OptiSpark” from enthusiasts’ collective memory. As we will see, that seems like a safe bet.
It’s Powerful…And Big
Due in part to tightening CAFE standards, many of us expected the new engine to displace somewhere in the range of 5.5 liters and generate less torque than the outgoing LS3. Happily, we were mistaken. The 6.2L LT1 puts out 450 hp at 6,000 rpm and 450 lb-ft at 4,000 rpm, handily eclipsing its predecessor on both counts. Even better, it’s expected to slingshot the base C7 to 60 mph in less than four seconds—as quick as a ’13 427 Convertible.
Speaking of uplevel Corvettes, Chevy has thus far remained tight-lipped on potential replacements for the LS7 and LS9 engines, both of which will cease production at the end of MY13. As I noted last month, we expect a supercharged LT4 variant to power the next ZR1, which could break cover as early as 2015.
Thanks to a suite of high-tech updates (more on those anon), the LT1 achieves an impressive 26-plus mpg on the highway, making it most fuel-efficient Corvette engine in history. Key to achieving that impressive figure is an active fuel-management system that shuts down half of the engine’s cylinders in light-load situations, effectively transforming it into a 3.1-liter four.
As I mentioned, the LT1 is chockablock with cutting-edge technological features, many of which have never been used in a Corvette engine until now. Direct injection and advanced piston topography help optimize the combustion process, enabling a heady 11.5:1 compression ratio, while continuously variable cam timing ensures that the valvetrain is always operating at peak efficiency.
As for the valvetrain itself, it features 1.8 rockers, hollow valves (50mm on the intake side, 40.4mm sodium-filled on the exhaust), and a “tri-lobe” camshaft that drives the high-pressure fuel pump necessitated by the direct injection system.
Enhanced output demands enhanced durability, and in this area, the LT1 does not disappoint. An all-new oiling system employs piston squirters, a high-performance pan, a variable-displacement pump, and an integral cooler to improve the engine’s oil/air-separation capability by a factor of three over the LS3. (A dry-sump system, with a healthy 11.5-quart capacity, will be available optionally.)
While the LT1’s basic architecture was inspired by the old LS engine platform, there are meaningful fortifications throughout. For example, the six cross-bolted main-bearing caps are now made of nodular iron, making them both stronger and more vibration resistant than the old powdered-metal units. The result? Greater durability at high revs (the factory redline is 6,600 rpm) and smoother, quieter operation at all rpm levels.
You Want One
“Our objective for the…LT1 was to raise the bar for performance car engines,” said Mary Barra, senior vice president, global product development, at the engine’s unveiling. “We feel that we have achieved that by delivering a true technological masterpiece that seamlessly integrates a suite of advanced technologies that can only be found on a handful of engines in the world.”
In an era of empty hype and broken promises, the people in charge of America’s sports car continue to exceed expectations.