2012 ECOTEC 1.8L I-4 VVT (LUW)

Vehicle Applications

Chevrolet Cruze

Chevrolet Sonic

Product Highlights

  • Structural, lightweight (hollow-frame) cast gray iron cylinder block
  • Dual-overhead camshaft configuration with four valves per cylinder
  • Dual continuously variable camshaft phasing
  • Variable intake manifold
  • Hollow-cast camshafts
  • Oil-water heat exchanger
  • Piston-cooling oil jets
  • Electronicallycontrolled cooling system
  • 138 horsepower (103 kW) at 6,300 rpm
  • 125 lb.-ft. of torque (168 Nm) at 3,800 rpm

Overview

As part of GM’s new generation of small-displacement, power-dense four-cylinder engines, the Ecotec 1.8Lis helping GM deliver more efficient yet fun-to-drive vehicles in North America. It leverages the technical expertise of engineers and designers around the globe, including South Korea. It is offered in the Chevrolet Cruze and Sonic; and is rated at 138 horsepower (103 kW) and 125 lb.-ft. of torque (168 Nm) at 3,800 rpm.

It delivers an excellent balance of performance and efficiency. It uses a number of advanced technologies, including a variable intake manifold for optimal performance across the rpm range, along with sequential fuel injection, coil-on-plug ignition and electronic throttle control. It also has a close-coupled catalyst that promotes faster “light off” for lower emissions.

The Ecotec 1.8L is designed for low maintenance, with many long-life features and components.

Cylinder Block

The cylinder block is made of strong gray cast iron, with five main bearings. To minimize weight, it features hollow-frame construction, making it about 20 percent lighter than a conventional casting. The block also incorporates a gray cast iron bedplate that helps enhance strength and durability.

Rotating Assembly

Anchoring the engine’s rotating assembly, the crankshaft was designed to deliver exceptional durability over a long engine life. The cast iron crankshaft is also relatively lightweight, which reduces the engine’s overall mass and promotes quicker, more immediate response to throttle changes.

The crankshaft is used with steel connecting rods, floating piston pin bearings, and high-strength, lightweight aluminum pistons.

Piston-Cooling Oil Jets

The Ecotec 1.8L incorporates piston-cooling oil jets to minimize piston temperatures, therefore helping to optimize performance, efficiency and emissions. The jets, mounted at the bottom of each cylinder, are part of the engine’s oiling circuitand spray engine oil at the bottom of the pistons.

Dual Overhead Camshafts

While overhead cams are the most direct, efficient means of operating the valves, four valves per cylinder increase airflow in and out of the engine. This arrangement is integrated on the Ecotec 1.8L’s lightweight aluminum cylinder head.

When designing the cylinder head, special attention was dedicated to the structural strength and the cooling. The inlet and exhaust port geometry was dimensioned by simulating the charge cycle and the flow. The front camshaft bearing bridge contains the control valves and the bores for the cam phasers’ oil supply. It also provides the basis of the thrust bearing.

Variable Valve Timing

Variable valve timing helps the Ecotec 1.8L deliver optimal performance and efficiency, with reduced emissions.It allows linear delivery of torque, with near-peak levels over a broad rpm rangeand high specific output (horsepower per liter of displacement), without sacrificing overall engine responseor driveability. It also provides another effective tool for controlling exhaust emissions.

The system changesvalve timing on the fly, maximizing engine performance for a variety of operating conditions. And because it manages valve overlap at optimum levels, it eliminates the need for an Exhaust Gas Recirculation (EGR) system.

Hollow-Cast and Chain-Driven Camshafts

The pair of camshafts in the Ecotec 1.8L arehollow and lighter than conventional solid shafts. Along with helping reduce the overall weight of the engine, they lower the inertia of the valvetrain, allowing the engine to rev higher and more quickly.

Driven by durable chains, the camshafts can be phased at the inlet side by 60degrees of crankshaft angle (CA) and 45degrees CA on the exhaust side, respectively.

Additional valvetrain elements include mechanical tappets with lightweight valves and springs. It also includes a vane-type cam phaser manufactured with a thin-wall forming process, which fosters low weight, minimal space requirements and a wide phasing authority.

Variable Intake Manifold

The Ecotec 1.8L’s two-stage variable intake manifold optimizes fuel economy and performance. At engine speeds below 4,000 rpm, inlet air passes through 35.8-inch-long (910 mm) intake tracts that help increase torque. At speeds greater than 4,000 rpm, a rotary sleeve within the lightweight composite intake manifold closes off the full length of the intake tracts, forcing air through a shorter, 10.2-inch (260 mm) path that helps build horsepower.

The rotary sleeve helps minimize airflow resistance at higher speeds, ensuring the maximum cross section area in the open position. The cross section of the intake runners is constant, with the length of the runners reduced by 60 percent in the closed position (greater than 4,000 rpm). This two-stage manifold helps the Ecotec 1.8L produce approximately 90 percent of peak torque from 2,400 rpm to 6,500 rpm, giving it a strong, responsive feel in all driving conditions.

Oil Circuit

The flow volume of the oil pump isdesignedto support the Ecotec 1.8L’s oiling requirements that include piston cooling and camshaft phasing. The increased thermal load of the oil requires the integration of an oil-water heat exchanger, which consists of a heat exchanger, oil filter and a coolantbypass tube. It is part of the engine’scoolant circuit.

The system is integrated on the exhaust side of the cylinder block and ensures optimal intercooling and oil pressure. During cold starts, it allows faster heating of the engine oil for earlier reduction of the internal engine friction.

The cam phasers are supplied with oil through separate bores in the cylinder block and head. The recirculation of the increased amount of oil in the cylinder head is permitted through additional pre-cast oil return channels.

Electronically controlled thermostat

The coolant thermostat’s operating point is electronically controlled to optimize engine temperatures during different phases of operation to enhance fuel efficiency. The engine control module monitors sensors and controls the thermostat based on mapping that takes into account the wide range of engine operating conditions, including temperature and load.

Maintenance

Built with a number of long-life and no scheduled maintenance components, the Ecotec 1.8L has improved engine durability, which helps reduce the overall cost of ownership.

Examples include:

  • The timing belt change interval is 10 years or 100,000 miles (160,000 km), whichever comes first.
  • The piston-cooling oil jets provide enhanced lubrication for increased engine longevity and extended maintenance intervals.
  • Nickel-tipped spark plugs have a maintenance interval of 100,000 miles (160,000 km).
  • The coil-on-plug ignition system eliminates spark plug wires, for greater operating reliability and lower maintenance requirements.

The Ecotec 1.8L I-4 VVT (LUW) is manufactured at the powertrain production facility in Bupyeong, South Korea.

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