L83/L8B 5.3L EcoTec3 Engine Specs: Performance, Bore & Stroke, Cylinder Heads, Cam Specs & More

This is an engine specification guide for General Motors’ fifth-generation L83 and L8B engines that launched in 2014.

These LT-based engines are commonly referred to as EcoTec3 5.3L engines. They are all-aluminum small blocks, both of which incorporate Active Fuel Management (AFM), Variable Valve Timing (VVT), and are flex-fuel capable (E85). The engines also use direct fuel injection technology, which shoots fuel directly into the combustion chamber instead of the intake runner.

The notable difference between the L83 and L8B engines is that the L8B includes GM’s eAssist powertrain, which combines the traditional gas-powered engine with an electric motor. The eAssist offers an additional:

• 44 foot-pounds of torque
• 13 horsepower
• Up to 12% increased fuel mileage

The L8B also uses stop/start technology that will shut down the engine at traffic lights and during slow, stop-and-go traffic. The engine uses a BAS3 (Belt Alternator Starter) in place of an alternator. The BAS3 recharges the battery AND is used to restart the gas engine after it shuts down. Other than the alternator, both engines use the same major components.

The information listed here is for a stock engine.

(Summit Racing’s Brian Nutter and Paul Spurlock contributed to this article.)

Chevy L83 & L8B Engine Specs

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