GM 6.0 Liter V8 Small Block L77 Engine
The L77 is an engine produced by General Motors for full-size vehicles. Displacing 6.0 liters in a V8 configuration, the L77 is part of the fourth-generation Small Block engine family and, for all intents and purposes, is the 6.0-liter Vortec L96 engine used in GM’s GMT900-based trucks and SUVs. It has been rumored that GM elected to use the L77 (over the LS3/L99) in the Chevrolet Caprice PPV (Police Package Vehicle) due to its Active Fuel Management (cylinder deactivation) technology as well as its ability to run on E85 ethanol fuel.
The L77 6.0L V8 offers Active Fuel Management (AFM) cylinder deactivation technology and FlexFuel capability, allowing it to run on E85 ethanol. Active Fuel Management allows the engine to operate on only four cylinders during certain light-load driving conditions, saving the fuel normally used to drive all eight cylinders. Intake flow was improved over previous engines by straightening out and optimizing the flow path from the intake manifold into the cylinder heads, while the exhaust ports are also designed for greater flow. The engine’s efficiency also optimizes emissions performance.
- Cylinder Block: the engine block was developed with math-based tools and data acquired in GM’s racing programs, and provides a light, rigid foundation for an impressively smooth engine. Its deep-skirt design helps maximize strength and minimize vibration. The bulkheads accommodate six-bolt, cross-bolted main-bearing caps that limit crank flex and stiffen the engine’s structure. A structural oil pan further stiffens the powertrain.
- High-Flow Cylinder Heads and Valvetrain: the L77’s cylinder heads feature rectangular intake ports that support exceptional airflow. They support great airflow at higher rpm for a broader horsepower band, along with strong, low-rpm torque. The intake ports that feed the combustion chambers, as well as the D-shaped exhaust ports, are designed for excellent high-rpm airflow.
- High-Flow Intake Manifold with Acoustic Shell: the L77’s intake manifold ports are designed to match the cylinder head. The composite manifold is manufactured with a lost core process to improve runner-to-runner variation and to reduce flow losses. Acoustic foam is sandwiched between the outside top of the intake manifold and an additional “skull cap” acoustic shell to reduce radiated engine noise.
- Advanced Electronic Throttle Control: with ETC, there is no mechanical link between the accelerator pedal and the throttle body. A sensor at the pedal measures pedal angle and sends a signal to the engine control module (ECM), which in turn directs an electric motor to open the throttle at the appropriate rate and angle. The ETC system can deliver outstanding throttle response and greater reliability than a mechanical connection.
- Active Fuel Management: AFM temporarily deactivates four of the L77’s cylinders under light load conditions and seamlessly reactivates them when the driver demands full power. AFM is managed by the engine control module (ECM). When conditions are optimal, it automatically shuts down every second cylinder, according to firing order, during light-load operation. As a result, AFM delivers better fuel economy and lower operating costs.
- 58X Ignition System: the L77 has an advanced 58X crankshaft position encoder to ensure that ignition timing is accurate throughout its operating range. The new 58X crankshaft ring and sensor provide more immediate, accurate information on the crankshaft’s position during rotation. This allows the engine control module to adjust ignition timing with greater precision, which optimizes performance and economy. Engine starting is also more consistent in all operating conditions.
|Type:||6.0L Gen IV V8 Small Block|
|Displacement:||5967 cc (364 ci)|
|Valve configuration:||Overhead valves|
|Valves per cylinder:||2|
|Assembly site:||Silao, Mexico|
|Valve lifters:||Hydraulic roller|
|Firing order:||1 – 8 – 7 – 2 – 6 – 5 – 4 – 3|
|Bore x stroke:||101.6 x 92 mm|
|Fuel system:||Sequential fuel injection (SFI)|
|Fuel type:||Premium fuel recommended, not required. E85 capable|
|Maximum Engine Speed:||6000 RPM|
|Positive crankcase ventilation|
|Valves per cylinder:||2|
|Bore Center (mm)||111.76|
|Engine Mass (kg/lbs)||183 / 403|
|Horsepower hp (kw)|
|Chevrolet Caprice PPV||355 hp (265 kW) @ 5300 rpm SAE Certified|
|Torque lb.-ft. (Nm)|
|Chevrolet Caprice PPV||384 lb-ft (521 Nm) @ 4400 rpm SAE Certified|
|Cylinder head:||Cast aluminum|
|Exhaust manifold:||Cast nodular iron|
|Main bearing caps:||Powder metal|
|Crankshaft:||Cast nodular iron with undercut and rolled fillets|
|Connecting rods:||Powder metal|
|Extended life spark plugs|
|Extended life coolant|
|Active Fuel Management|
|Oil Life Monitor System|
|Oil Level Sensor|
|Electronic throttle control|
|Extended life accessory drive belt|
|Chevrolet Caprice PPV||MYC-6L80|