Chevy 283-cid V-8 Engine

The iconic small-block Chevy V-8 reached a significant milestone in 1957. While the 265 remained the base engine, the highlight was the introduction of the 283-cid version, achieved by increasing the bore to 3.88 inches. The base model delivered 185 bhp at 4600 rpm, while a four-barrel carburetor pushed it to 220 bhp. Dual four-barrel setups produced either 245 or 270 bhp, and Chevy's innovative "Ramjet" fuel injection system elevated output to 250 or 283 bhp. The latter achieved the legendary one horsepower per cubic inch and was paired exclusively with a close-ratio three-speed manual transmission.

The "fuelie" was engineered for exceptional reliability. Mechanical valve lifters replaced hydraulics in fuel-injected models. Longer-reach spark plugs with metal shields were used to safeguard wiring and plug caps from manifold heat. The block's top section was reinforced to prevent cylinder wall distortion from over-tightened bolts. Fuel passages were tapered, expanding toward the inlet ports and within the "ram's horn" exhaust manifold to enhance scavenging and volumetric efficiency. A redesigned distributor positioned breaker points directly above the shaft bearing to minimize gap setting fluctuations, and the front and intermediate main bearings were thickened by 0.063 inches.

Developed primarily by the Engineering Staff and streamlined for production by Harry Barr and Zora Arkus-Duntov, the Ramjet fuel injection system was manufactured by GM's Rochester carburetor division. It featured three key elements: the fuel meter, manifold assembly, and air meter, which replaced the traditional intake manifold carburetor. Air was drawn in first, followed by precise fuel injection into each intake port for optimal mixing. This system ensured highly accurate fuel control, enhancing volumetric efficiency and fuel economy. Cold-weather performance and warm-up times were improved, and the system alone increased output by approximately 5 bhp compared to the twin four-barrel carbureted engine. Chevrolet also highlighted benefits such as eliminating manifold icing and reducing stalling during sharp turns.

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Chevy 283-cid V-8 Engine Overview

The 283 V-8 engines with fuel injection utilized a unique two-piece aluminum manifold casting. The upper section housed air passages and bases for the air/fuel metering system, while the lower section formed the ram tubes and covered the engine's top center.

Significant engineering advancements are rarely straightforward, and the Ramjet injection system was no exception. Despite being a landmark achievement for Chevy, it faced initial challenges. For instance, during Daytona Speed Weeks, an issue with fuel cutoff during acceleration was resolved to eliminate a flat spot in performance. Fuel nozzles also required adjustments, as they were extended further into the air stream to prevent overheating, which caused rough idling.

While no official tests were conducted on the fuel-injected 283 in a standard Chevrolet, its performance in Corvettes is noteworthy. The most powerful versions achieved 0-60 mph acceleration times averaging just over 6 seconds, with top speeds reaching around 140 mph. Walt Woron of Motor Trend magazine, driving a 250-bhp FI Corvette (33 bhp less than the 1957 peak), recorded a 0-60 mph time of 7.2 seconds. A modified 283 with 10.5:1 compression, dual exhausts, a high-performance cam, and solid lifters reached 134 mph, leading Woron to believe the car had even more potential. Based on these results, a two-door sedan weighing 400 pounds more than the Corvette could likely achieve 0-60 mph in approximately 8 seconds and a top speed of 120 mph with optimal gearing.