L81 Engine Specificationsby Vern Hee
The L81 engine was manufactured for the 1981 Corvette at the end of the C-3 generation of Corvettes. This generation of Corvette had boldly come out in 1968 with a drastic redesign of the Corvette body, which made it sleeker and lower to the ground. Its slick new design in 1968 was equipped with a powerful power plant that made it capable of going 200 mph. As the muscle car era drew to a close, the horsepower outputs gradually were lowered and the L81 was part of that lowering.
L81 Engine Stats
The L-81 displaced 350 cubic inches at 5.7 liters. It had an overhead valve configuration made with cast iron blocks with two valves per cylinder. The new engine boasted new lightweight magnesium rocker arm covers and new stainless-steel free-flowing exhaust manifolds. The engine also was equipped with a new Computer Command Control system which controlled metering. The 350 engine had a power output of 190 horsepower at 4,200 rpm with a torque of 280 foot-pounds at 1,600 rpm. The L-81 had a compression ratio of 8.2:1 and the engine redlined at 5,100 rpm. The L81 was equipped with a four-barrel Rochester carburetor and had a bore and stroke of 4.0 inches x 3.48 inches. The L81 engine went from 0 to 60 in 7.2 seconds.
Corvette manufactured a series of 350 cubic engines leading up to the year 1981. The L48 350 engine in 1979 raised horsepower to 195, and the L82 raised output further to 225 horsepower. In 1980 the base L48 engine put out 190 horsepower and the L82 was rated at 230 horsepower. By 1981 the only powertrain combinations available to the Corvette was the new L81 with 190 horsepower. The subsequent year, the L81 was the only engine available also.
In 1982 the L81 received throttle body injection called crossfire injection, and this changed its designation to the L83. This system used two throttle bodies above the intake manifolds. The fuel injected into the throttle body was controlled by a General Motors computer. This new computer had the ability to make 80 adjustments per second. The "crossfire injections system" was the prelude to more advanced fuel-injection systems. This fuel-injection system increased the horsepower output by 10 horsepower up to 200 horsepower at 4,200 rpm with a torque of 285 foot-pounds at 2,800 rpm.
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