Behind every iconic performance car, is an equally iconic engine that breathes life into every ounce of the engineering marvel in which it is housed. Not to disappoint, the Corvette has seen its fair share of noteworthy powerplant options, many of which have been nothing short of revolutionary in design.
For nearly 70 years, the true American sports car has been pushing the performance envelope, breaking barriers, and discrediting doubters, with much of the reason for this success residing under the hood.
If you have been a Corvette enthusiast since the model’s 1953 inception, a certain level of gratitude for the 1955 256ci V8 is due, because, without its timely arrival, your fanfare might very well have been short-lived. Faced with less than overwhelming sales figures up to this point, GM engineers were left scrambling to bring the Corvette to prominence, or else risk its untimely demise.
The Corvette’s original 235 cubic-inch power plant faced critical reception, much of which stemmed from its woefully inadequate output of approximately 150 HP. So when in 1955 the 265 cubic-inch V8 hit the road churning out 195 HP, many who had all but condemned the Corvette as a production failure were forced to give it yet another look.
Though this engine had a fairly short-lived tenure under the hood of America’s sports car, it righted the sinking ship that was the first-generation Corvette.
1957 283 Cubic-Inch V8
Though the 265 cubic-inch offerings for 1955 had essentially brought the Corvette off life support, sale numbers were still far from impressive, and few viewed these cars as a serious performance offering. This all changed with the 1957 introduction of the 283 cubic-inch V8.
Offered in both carbureted and “Ramjet” fuel-injected varieties, the 283 cubic-inch engine upped the horsepower ante and bolstered sales far beyond what had been recorded in previous years.
Some speculation surrounds the actual horsepower ratings of the 283 cubic-inch engine. It is widely reported that the top end fuel-injected variant cranked out approximately 290 HP.
However, these numbers were said to be downplayed in an attempt to capitalize on marketing hype surrounding a 1:1 ratio, as it pertains to horsepower versus engine displacement. It is also often stated that the dual carburetor option’s 270 HP rating was understated as a means of pushing GM’s innovative Ramjet fuel injection.
1962 327 Cubic-Inch V8
By 1962, few had any remaining doubts as to the Corvette’s status as an elite performance car of the day. However, GM was about to erase any remaining doubts with a high level of assurance.
As the 327 cubic-inch V8 became standard in 1962, the Corvette became the benefactor of substantial gains in both horsepower and torque. The 327 featured the same general engine block as its 283 predecessors, though it was bored into and stroked to increase the cylinder dimensions to 4.00 x 3.25 inches.
Four variants of the 327 were available for the 1962 production year, with all featuring differing horsepower ratings. At the lower end of the spectrum was the standard cam offering featuring the baseline four-barrel carburetor that was rated at 250 HP. The year’s top-tier offering featured a Duntov designed specialty cam, as well as fuel injection, and cranked out a staggering 360 hp.
The L36 offering was rated at a noteworthy 390 HP. The latter of the two options, the L72 churned out an impressive 425 HP and featured an 11:1 compression ratio, a sizeable Holley four-barrel carburetor, and mechanical lifters.
Perhaps the most interesting aspect regarding the 427 was that both the L36 and the L72 engines were often said to be highly underrated in their respective horsepower values. It is commonly relayed that the L36 peaked far closer to 420 HP, while the L72 produced approximately 450 hp.
1970 454 Cubic-Inch LS5
As the demand for ever-increasing performance continued, Chevrolet sought to answer, in any necessary form, to stay on the industry’s cutting edge. Their answer came in the form of the new 454 cubic-inch big-block LS5 engine.
The addition of the LS5 and it’s more than capable 390 HP output was thought to be a direct reflection of the horsepower wars of the day. Though not nearly as popular as the small-block options, it is hard to discount this 500 ft/lbs of torque producing beast.
The 1970s were a changing time in the American performance car scene, and the race for mind-numbing horsepower such as the ZR1 was eventually choked out due to increasingly strict emission standards. Unfortunately, this meant that the LS5 came under scrutiny, leading to a short-lived lifespan as the 390 HP producing monster that it was. In short order, it had disappeared from the Corvette’s list of powerplant options.
1970 350 Cubic-Inch LT-1
In 1970, the Corvette’s 350 cubic-inch small-block was given a facelift that ultimately led to the production of what would be designated the LT-1 series of engines. The LT-1 featured a solid lifter design and was topped with the same Holley carburetor that was standard of the day’s high output big-block engine. Couple this with an improved Delco transistor-based ignition system and you had a small-block powerhouse that was a force to be reckoned with.
The LT-1 turned out an impressive 370 BHP and was capable of covering the quarter-mile in 14.2 seconds, with a top speed of 102 MPH. In fact, the LT-1 was offered within the confines of GM’s SCCA Class B Production car series for those wishing to order a race-ready Corvette directly off the assembly line. The addition of a cold-air hood and relevant chassis upgrades turned the 1970 Corvette into a bonafide racecar of its day.
1985 350 Cubic-Inch L98
After a prolonged era fraught with ever-stifling emissions mandates, the 350 cubic-inch L98 was introduced in 1985. The release of the L98 was a milestone for the Corvette line, as it signaled the beginning of its return to glory in the area of under hood performance.
This was of immense value, as the Corvette had made great strides in the areas of handling and drivability, leading to a car that was yearning for increased output for improved all-around performance.
After the dismissal of the short-lived Cross-Fire injection engines of 1984, the L98 featured a new Tuned-Port Injection system and a .5 increase in compression, thereby bumping the output of GM’s 350 platforms by 25 HP. These changes also yielded a 40 ft./lbs increase in torque.
In all, the new L98 was rated at 230 BHP and 330 ft./lbs of torque, making this engine a much-needed breath of fresh air for Corvette enthusiasts craving a little more at the business end of the gas pedal.
1990 5.7L/350 Cubic-Inch LT5
When the LT5 came onto the market in 1990, there had yet to be any engine displaying this magnitude of technological advancement to ever be placed in a Corvette.
By the late 1980s, GM had decided that they wanted nothing more than to delve back into the performance scene that they were so synonymous with during the American muscle era. However, GM also had a relative laundry list of demands that were to be met during the design process, many of which directly pitted performance and fuel economy against each other.
Engineers from Group Lotus of England were drafted to assist in the design of this engine that would meet the lofty demands that GM had set forth. How did they respond? With a 375 HP engine that cranked out 370 ft./pounds.
Although based on the LS1’s 5.7-liter construction, the LS6 made great strides in improving efficiency pertaining to the uptake of air into the intake. The theory was that the increased volume of air would lead to the acceptance of increased fuel volume, and therefore give way to a significant gain in horsepower.
The LS6 was fitted with higher compression aluminum heads, an updated intake, and stronger valve springs. Additional upgrades included upsized fuel injectors and an enhanced cam profile, both of which took advantage of the engines significantly increased intake airflow. When the smoke cleared, the new LS6 produced a formidable 385 HP and 385 ft./lbs of torque.
With a 0-60 time of only 2.95 seconds when paired with the 8-speed transmission and lateral acceleration of 1.6 g., the LT4 fitted Stingrays were not for the faint of heart. The achievement of this level of sheer power was due in large part to the LT4’s forced air induction design, made possible by the use of its high volume supercharger.
The LT4 came paired with the choice of a 7 or 8-speed transmission, both of which complimented the attributes of this powerhouse magnificently. The engine was tested and certified at a rating of 650 HP and 650 ft./lbs of torque.
The LT4 set blistering times in the quarter-mile as well, clocking in at 10.95 seconds when paired with the 8-speed transmission, and 11.2 seconds when paired with the 7-speed offering.