The technology being introduced in the internal combustion engine has delivered a smarter working engine producing fewer emissions, resulting in engines that are more efficient, yet more powerful, than ever before. Emissions standards continue to become stricter each year. Internal engine design changes and exhaust aftertreatment are some of the ways those new standards are being met.
(Fig. 1)
The new technology of the modern internal combustion engine (Fig. 1) is highlighted in four new modular ACDelco seminars. Designed to be offered as one-hour "Lunch-and-Learn" training events, they can be delivered as one-hour stand-alone courses or combined to provide an in-depth training program for your service center.
The new Internal Combustion Engine Technology seminars are:
· Advanced Variable Valve Timing
(S-EM01-01.01SEM)
· Camshaft Variable Lift Systems and Active Fuel Management
(S-EM01-02.01SEM)
· Spark Ignition Direct Injection
(S-EM01-03.01SEM)
· Homogenous Charge Compression Ignition
(S-EM01-04.01SEM)
Advanced Variable Valve Timing
Variable Valve Timing (VVT), also known as cam phasing, dynamically changes valve timing events relative to piston timing by controlling the camshaft. By advancing or retarding cam timing, the engine can improve low-end torque, high-end horsepower or light-load fuel economy -- all while reducing emissions.
The seminar covers the operation of the different types of cam phasing devices: spline phaser in overhead cam engines, and vane phasers in overhead cam engines and cam-in-block engines. (Fig. 2) System testing and service precautions are reviewed as well.

(Fig. 2)
Camshaft Variable Lift Systems and Active Fuel Management
A camshaft variable lift system is an advanced variable valve actuation technology that changes valve lift, duration and timing. In this seminar, the operation of several different valve lifter systems is covered, including a look at the roles of various components such as the valve lifter, oil switching valve, and engine oil pressure switch/oil temperature sensor.
In addition, the seminar reviews the GM Active Fuel Management system, which deactivates four of the eight engine cylinders during certain driving conditions to reduce fuel use. It explains, for example, the operation of the valve lifters -- eight for deactivation and eight for non-deactivation -- in V8 mode and V4 mode.
Spark Ignition Direct Injection
Mechanical direct fuel injection was first used in passenger cars in 1952. The Spark Ignition Direct Injection (SIDI) system in today's engines offers the advantages of smaller displacement engines, improved efficiency and reduced emissions. SIDI delivers fuel directly into the combustion chambers during the intake stroke, which is ignited by the spark plug to begin combustion. (Fig. 3)

(Fig. 3)
The seminar covers the SIDI operating modes and the combustion process. It also highlights the operation and components of the fuel system, including the fuel rail, fuel rail pressure sensor, high pressure fuel line, high pressure fuel pump, low pressure line, and high pressure fuel injectors.
A new fuel injector technology -- piezoelectric injectors -- also is covered. These high voltage injectors use piezo crystal actuators that switch five times faster than a solenoid operated injector.
Homogenous Charge Compression Ignition
The Homogeneous Charge Compression Ignition (HCCI) is a combustion system where a homogeneous air/fuel mixture is ignited by compression. (Fig. 4) It has the potential to improve efficiency without requiring complex lean exhaust aftertreatment, helping to deliver a fuel savings of 15%.

(Fig. 4)
This seminar reviews the operation of HCCI technology as well as the valvetrain and injection strategy used in a HCCI engine. Since HCCI combustion is sensitive to a number of factors, such as climate, humidity and fuel composition, a variety of injection parameters and valvetrain adjustments are made during operation.
Learn More
In addition to the new engine technology seminars, ACDelco offers on-demand, online, Web-based courses and a variety of instructor-led, hands-on courses. To review the latest training courses available, log in to the ACDelco Learning Management System (LMS) at www.acdelcotraining.com.
To learn when ACDelco seminars will be scheduled in your area, contact your local ACDelco distributor.
- Thanks to Mike Militello
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