A DEEPER LOOK AT THE SMALL-BLOCK HEART OF THE 2014 CORVETTE

By Chris Paukert, Autoblog.com - If it's never been said before that the cornerstone to General Motors performance is the small block V8, well, it ought to be on a factory plaque somewhere.  And maybe some t-shirts.  We can start printing up the latter right now:  The General's evergreen performance linchpin is getting a 21st-century makeover in the form of this all-new 6.2-litre LT1.

Revealed this morning at GM's Powertrain Development Center in Pontiac, Michigan, the new small block will be at the heart of the 2014 C7 Chevrolet Corvette, and variants are also expected to find their way into other GM vehicles in short order, including the automakers' full-size Chevrolet Silverado and GMC Sierra pickups (which are also on schedule for new 2014 models).

We revealed the key specs as the press conference unfurled this morning; a minimum of 450 horsepower and 450 pound-feet of torque, 0-60 mph (96 km/h) in under four seconds for the base Corvette and around 8.7L/100km (27 mpg).  Critically, despite being a large displacement engine, the fifth-generation small block stays true to its roots with a compact footprint -- GM claims the engine is four inches lower and more compact overall than BMW's 4.4-litre twin-turbo V8, yet it weighs 40 pounds (18 kg) less.

Key new technologies for the engine include direct injection and continuously variable valve timing, along with Active Fuel Management, a technology that GM tried to input on the last Corvette but officials admitted they had to scuttle the tech due to refinement issues -- problems have been solved now.  All that new hardware means that the LT1 is actually slightly heavier than the outgoing LS3 V8, but it's still very lightweight.  Traditionalists will appreciate that the cam-in-block pushrod engine keeps the bore spacing and block length of its predecessors, but make no mistake, this is an all-new engine -- the sum total of the carryover parts fit comfortably inside a small Ziplock baggie.

While GM officials wouldn't disclose further details about the upcoming C7's powertrain (transmission, etc), they did opaquely confirm that an active exhaust system will return.  Engine and exhaust sound is a key part of delivering the V8 experience, and engineers say they've worked hard to ensure that the Corvette's auditory thunder continues.  When Autoblog noted that the inclusion of direct-injection can bring along with it some unpleasant engine sound ramifications, the engineering team noted that burying some of the hardware in the engine valley (under the intake manifold and blanketed by acoustic foam) has removed much of the unpleasant DI pump clatter at idle as well as under load.  (Officials gleefully noted that the DI tech is so buried in the vee that cutaway artist extraordinaire David Kimble had a hard time locating the hardware to render it in his artwork!)

While previous speculation had the new small block pegged at 5.5-litres, GM says they went with a larger 6.2-litre displacement because of the advantages of cylinder deactivation, which effectively has the LT1 operating as a 3.1-litre V4 under lighter loads.  If GM had made the engine's displacement smaller, the V4 mode wouldn't have provided as much power, and thus drivers wouldn't have the engine operating in cylinder deactivation mode as often in daily driving.  By operating in full-on V8 mode more often, GM would have negated the efficiency benefits of going with a smaller displacement.

It was just about a year ago, at the end of November, 2011 when GM announced it had built its 100-millionth small block.  And while GM wisely doesn't anticipate building another 100 million, this new LT1 shows that there's a lot of life left in V8 engines -- certainly enough for millions more.