Last month, VETTE took you behind the scenes to GM's state-of-the-art Performance Build Center for the creation of the 100-millionth Chevrolet small-block. The milestone mill--a 6.2L LS9 rated at 638 hp--was assembled by Skilled Engine Builders who build Corvette's LS3 dry-sump, LS7, and LS9 engines. They were assisted by special guests, including retired Chevrolet executives and engine engineers, and media journalists.
This month, we'll continue the small-block celebration by asking GM's official illustrator, David Kimble, to help us pick 10 of the most significant Chevy small-blocks that were (and are) factory-issue in America's Favorite Sports Car.
To date, Kimble has illustrated nearly every Chevrolet production small-block engine, and he's working on detailed, cutaway illustrations of the Gen V small-block, which will power the Corvette line beginning in '14.
Kimble is contractually obligated to not divulge details of the fifth-generation small-block until General Motors gives the nod, but Tom Read, GM Powertrain Communications, let us tear loose some non-classified tidbits from him.
"The fifth-generation small-block is under development and moving forward as planned," Read says. "The engineering center and development lab in Pontiac, Michigan, is working full-throttle to bring the best-ever engines online soon. The new small-blocks will feature an entirely new, direct-injection combustion system that will really help improve efficiency over the current-generation engine. We're investing more than $1 billion in manufacturing facilities associated with producing Gen V small-blocks, including Tonawanda, St. Catharines, and various locations in Mexico. Additional good news is that [the investment] will result in 1,711 jobs [being] created or retained. We can confirm that Defiance Casting Operations of Defiance, Ohio, has signed on to manufacture the Gen V engine blocks and cranks, and Bedford Powertrain of Bedford, Indiana, is on board to manufacture the cylinder-head castings."
Read also intimated that the LS nomenclature can't and will not carry over to fifth-gen small-block V-8s. That means you shouldn't expect the engine order codes LS10 or LS11 moving forward. Instead GM will use a new three-digit alphanumeric sequence for Gen V, though exact details are still top secret.
While you're waiting for Chevrolet's fifth-generation small-blocks to find their way into Corvettes of the not-so-distant future, come along with us and enjoy an insider's look (literally) at 10 of the most-significant Chevy small-blocks to power production Corvettes in the last 60 years.
Note: Kimble states that he considers the '70 LT1 and the '85 L98 among Chevrolet's/Corvette's most significant small-blocks, but he hasn't had the opportunity yet to illustrate them.
Gen I (1955-1991)
(Note: Alphanumeric engine-order codes do not begin until '63)
Displacement 265 ci
Bore x Stroke 3.75- x 3.00-in
Fuel System Carter Wrought Cast Four Barrel (WCFB) carburetor
Horsepower/Torque (lb-ft) 195/260
Cam Solid-lifter, 264/266-deg duration, 0.404/0.413-in lift
Did you know? Model-year 1955 Corvettes optioned with the Chevy V-8 small-block featured an enlarged, gold "V" in the Corvette script on the front fenders. The Corvette's powerplant was rated 15 hp higher than the V-8/four-barrel slated for Chevrolet passenger cars, thanks to a more-aggressive-lift cam. Unlike the large-domed oil-bath filter used with other Chevy V-8s that year, Corvette's powerplant featured a stylish, louvered, less-restrictive, air cleaner with an element that consisted of oiled lathe chips. The firing order was 1-8-4-3-6-5-7-2 and stayed that way through '96.
Displacement 265 ci
Bore x Stroke 3.75- x 3.00-in
Fuel System Carter Wrought Cast Four Barrel (WCFB) carburetor (standard); two Carter Wrought Cast Four Barrel (WCFB) carburetors (optional)
Horsepower/Torque (lb-ft) 210/268 (standard), 225/270 (optional)
Cam Solid-lifter, 264/266-deg duration, 0.404/0.413-in lift (standard); solid-lifter "high-lift," 287/266-deg duration, 0.404/0.413-in lift (optional)
Did you know? Corvette's base engine increased in horsepower due to added compression and new ram's-horn exhaust manifolds, which were less restrictive than the previous model year's log-style manifolds.
Adding RPO 469 to a Corvette sales order upped the V-8's ante to 225 hp. It included Chevy's first V-8 aluminum intake manifold, which housed two Carter four-barrels.
A special "high-lift" camshaft (RPO 449) became available late in the year, with a "for competition use only" warning. Oddly, the cam's duration--not its lift--was higher, according to some Corvette historians. A total of 111 of these bumpsticks were factory installed, and an unknown number were sold over-the-counter, despite the fact that Chevrolet never published an official horsepower rating for engines so equipped.