- GM reveals the fifth generation of its legendary small-block V8, a 6.2-liter overhead-valve design that is designated LT1 for the 2014 Chevrolet Corvette.
- Preliminary figures: 450 horsepower at 6,000 rpm, 450 pound-feet of torque at 4,500 rpm and a sub-4-second 0-60 run.
- Biggest changes compared with the current Corvette's LS3 6.2-liter V8: direct injection, variable valve timing and cylinder deactivation.
PONTIAC, Michigan — There's an all-new generation of General Motors Co.'s legendary small-block V8 just around the corner and it's a major deal. Not only is the LT1 6.2-liter version unveiled here today the power plant for the coming C7 Corvette, but a high-volume version of this V8 architecture extends to the pending new generation of GM's pickups launching in early 2013.
Enthusiasts concerned there might be turbos or downsizing or some sort of general retreat in engine performance can rest easy: The new LT1 6.2-liter V8, which still uses an overhead valve design with pushrods and two valves per cylinder, makes a good bit more power than the LS3 V8 it is replacing.
The new LT1 for the 2014 Corvette is projected to develop 450 horsepower at 6,000 rpm and 450 pound-feet of torque at 4,500 rpm versus the max 436 hp at 5,900 rpm and 428 lb-ft at 4,600 rpm available from the current Corvette's LS3 V8. The fuel cutoff is at 6,600 rpm. Chevrolet said flatly that the latest LT1 is "the most powerful and efficient standard engine ever" in the Corvette's six-decade history.
Today's reveal dispelled longstanding rumors that the Corvette's fifth-generation small-block V8 would downsize to 5.5 liters. There are major architecture advances, however, for the new LT1 (which does retain the hallowed 4.4-inch bore center that defines a "small block"): the engine has direct injection, continuously variable valve timing and GM's Active Fuel Management cylinder deactivation — all firsts for a Corvette V8. It also uses an aluminum block with 6-bolt nodular main caps for strength and aluminum cylinder heads.
The regular production option (RPO) designation of LT1 is resurrected for the third time in Corvette history — the first (LT-1 with a hyphen) was a raucus, high-revving variant for the 1970 Corvette lineup, and the second LT1 came with the launch of the second-generation small-block in 1992 and had a five-year run.
The new LT1 derives its power and efficiency gains from a heady 11.5:1 compression ratio, the highest ever for a base production Corvette V8, said small-block chief engineer Jordan Lee.
Despite the big compression number, GM engineers say premium unleaded fuel will be recommended but not required for the 2014 Corvette, although there is as yet no detail on how much power will be compromised with regular-grade gasoline.
In cylinder-deactivation mode, the new LT1 will run as a 3.1-liter V4. Engineers here said only the capability available from the all-new Corvette architecture allows V4 operation without unacceptable trade-offs in refinement. Although GM admits the LT1 is heavier than the outgoing LS3, the new small-block is nearly 40 pounds lighter than BMW's 4.4-liter twin-turbo V8.
Despite the power and torque upgrades from the new LT1, fuel economy for the 2014 Corvette is expected to remain essentially the same as the current base Corvette's 15 mpg city and 26 mpg highway for the manual transmission.
Edmunds says: This is GM's engine analog to the Porsche 911 — everlasting but always contemporary and satisfying. We'll know soon enough how the fifth-generation small-block V8 works on the road.