The wraps won't come off of the 2014 Chevrolet Corvette until January 13 in conjunction with the 2012 Detroit Auto Show, but we now know exactly what will be under the hood of the next-gen "C7" Corvette. Motivation will come from GM's all-new Gen 5 Small Block V8. Designated LT1 and displacing 6.2 liters, this fifth incarnation of the world's most iconic V8 engine is a compact, tech-rich exercise that promises to give America's Sport Car a performance boost on every level.
While output numbers on this comprehensively redesigned engine have not been finalized, Tadge Juechter, Corvette chief engineer, has confirmed preliminary ratings of 450 horsepower and 450 lb-ft of torque -- stats that top the 430/424 numbers of the current model's LS3 base engine and make the new LT1 the most powerful standard Corvette engine in the car's 60-year history. That muscle is expected to deliver sub-4.0 second 0-60 mph times, which will ensure that the new C7 is the quickest standard Corvette ever as well, when it goes on sale late next year. And the LT1's formidable array of mileage-maxing features also will make certain the 2014 Corvette is the least thirsty variant, with an EPA highway mileage mark that exceeds the current car's 26-mpg rating. "By leveraging technology, we are able to get more out of every drop of gasoline and because of that we expect the new Corvette will be the most fuel-efficient 450 horsepower car on the market," Juechter said.
Although the new Gen 5 LT1 retains the classic 4.4-inch bore centers that have been a common Small Block trait since the Gen I was introduced in 1955 as well as an overhead valve design with 2 valves per cylinder, literally every other element of the engine has been redone. To emphasize the point, Jordan Lee, Small Block chief engineer and program manager, held up a small plastic baggie that contained all of the Gen 4's carryover parts: starter mounting bolts, piston pins and valve keepers.
Compact in size and rendered in lightweight aluminum, the Gen 5 now features direct fuel injection - the first fitment on an overhead valve engine -- continuously variable valve timing and Active Fuel Management (AFM). Better known as cylinder deactivation, AFM allows the LT1 to function as a V4 under light load conditions. While all three have been used on other GM engines, this marks the first appearance of any in a Corvette application. Their synergistic interaction is the key to making the Corvette's new V8 a viable alternative to reducing size or cylinder count in an era of increasingly stringent EPA requirements.
Despite early speculation that the new Gen 5 V8 might displace only 5.5-liters - same as the engine used in the current Corvette Racing C6.R models - Juechter says the 6.2-liter scale was a function of the mission-critical AFM system. Holding size will permit the Corvette's new LT1 to operate on just four cylinders through a far greater part of the car's "normal" duty cycle to effectively boost mileage yet still ensure it can serve up its formidable power and torque at a moment's notice. Speaking of the latter, that kick-you-back-in-the-seat commodity has been seriously elevated in the new LT1. While significantly better than the LS3 throughout its entire rev range, below 4,000 rpm, the new LT1's torque output is fully comparable to the 7.0-liter LS7 engine in the current Corvette Z06 variant.
"The power and efficiency of the Small Block V8 are hallmarks of Corvette performance," said Lee. "But, the compact size and great power-to-weight are just as important for the overall driving experience. The all-new LT1 will play a huge role in making the all-new Corvette a world-class sports car, in terms of technology, performance, and refinement."
While the focus of the initial Gen 5 Small Block briefing was strictly on its appearance in the 2014 Chevrolet Corvette, the new LT1 V8 is destined to make an appearance in a number of other GM products. The first to get a bespoke version will be the new 2014 Chevrolet Silverado 1500 and GMC Sierra 1500 full-size pickup trucks which will be unveiled next month. The engine also is slated to be in the upcoming 2014 Chevrolet SS performance model that also will arrive late next year and it will filter through the rest of the corporate lineup anywhere a V8 engine is required. Although even the most optimistic GM execs don't think the new Gen 5 Small Block will be able to match the 100,000,000-plus production volume of the first four generations, they are confident that the new Gen 5 will be around long enough to rack up build numbers "in the millions" and keep performance fans of all stripes happy for years, if not decades, to come.
For an in-depth look at the new LT1 engine, click here