10-11-2012, 11:59 AM
Ignition System
[attachment=38890]
An ignition system is a system for igniting a fuel-air mixture. Ignition systems are well known in the field of internal combustion engines such as those used in petrol (gasoline) engines used to power the majority of motor vehicles
PRIMARY IGNITION SYSTEM
-consists of the ignition switch, coil primary windings, distributor contact points, condenser, ignition resistor, and starter relay.
Ignition Switch
Does at least three things:
1. It turns on the car's electrical system.
2. In the run position, everything is turned on, plus the engine's electrical components that enable it to run. Most important, it turns on the entire primary ignition system.
3. When you move the switch to the "start" position it energizes the starter.
*The ignition switch doesn't carry the necessary current to the starter. It sends a small current to a special device called a Relay that, in turn, allows the starter to crank.
Primary Winding
Inside the coil are two sets of wound wire, comprising of the primary and secondary windings. The primary windings carry battery voltage through and create a large magnetic field inside the coil (this is discussed thoroughly in the section on secondary windings). Although the coil's primary windings receive voltage from the ignition switch, they are actually turned on and off by the distributor's contact points.
Contact Points
are opened and closed by a cam on the distributor's main shaft. As it spins the cam's lobes move the actuator outward, disengaging the contacts. When the lobe passes, the contacts close, turning on the coil primary windings. The amount of time the points remain closed is referred to as dwell, and is an important factor in engine tuning.
Condenser
Attached to the points is a condenser, an electrical device (capacitor) that limits current flow through the points to increase their life. The condenser is necessary because the points are opening and closing rapidly, and as they do so the voltage/current is interrupted. This causes an arc, or spark, between the contact points. Over time, this arcing will erode the material on the points and deposit carbon, and eventually the points will not pass current. The condenser acts as a current-absorber to limit the amount of arcing as the points open and close.
Ignition Resistor
is necessary because ignition coils are designed to step up battery voltage high enough - and fast enough - to keep the engine running at high rpm. That means that, as designed, the coil would produce too much high voltage at low rpm and heat up.
Starter Solenoid
A starter solenoid (or starter relay) is the part of an automobile which relays a large electric current to the starter motor, which in turn sets the engine in motion. In many vehicles the solenoid also engages the starter pinion with the ring gear of the engine.
Spark Plugs and Wires
A spark plug is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the engine. A spark plug has a metal threaded shell, electrically isolated from a central electrode by a porcelain insulator.
Spark plug wires are critical to deliver spark to a high performance engine. It's important to choose the right type of spark plug wires for your car. You should consider heat resistance, chemical resistance, ohm rating, RFI Suppression, cut-to-fit or direct fit and even the color when choosing high performance spark plug wires.
[attachment=38890]
An ignition system is a system for igniting a fuel-air mixture. Ignition systems are well known in the field of internal combustion engines such as those used in petrol (gasoline) engines used to power the majority of motor vehicles
PRIMARY IGNITION SYSTEM
-consists of the ignition switch, coil primary windings, distributor contact points, condenser, ignition resistor, and starter relay.
Ignition Switch
Does at least three things:
1. It turns on the car's electrical system.
2. In the run position, everything is turned on, plus the engine's electrical components that enable it to run. Most important, it turns on the entire primary ignition system.
3. When you move the switch to the "start" position it energizes the starter.
*The ignition switch doesn't carry the necessary current to the starter. It sends a small current to a special device called a Relay that, in turn, allows the starter to crank.
Primary Winding
Inside the coil are two sets of wound wire, comprising of the primary and secondary windings. The primary windings carry battery voltage through and create a large magnetic field inside the coil (this is discussed thoroughly in the section on secondary windings). Although the coil's primary windings receive voltage from the ignition switch, they are actually turned on and off by the distributor's contact points.
Contact Points
are opened and closed by a cam on the distributor's main shaft. As it spins the cam's lobes move the actuator outward, disengaging the contacts. When the lobe passes, the contacts close, turning on the coil primary windings. The amount of time the points remain closed is referred to as dwell, and is an important factor in engine tuning.
Condenser
Attached to the points is a condenser, an electrical device (capacitor) that limits current flow through the points to increase their life. The condenser is necessary because the points are opening and closing rapidly, and as they do so the voltage/current is interrupted. This causes an arc, or spark, between the contact points. Over time, this arcing will erode the material on the points and deposit carbon, and eventually the points will not pass current. The condenser acts as a current-absorber to limit the amount of arcing as the points open and close.
Ignition Resistor
is necessary because ignition coils are designed to step up battery voltage high enough - and fast enough - to keep the engine running at high rpm. That means that, as designed, the coil would produce too much high voltage at low rpm and heat up.
Starter Solenoid
A starter solenoid (or starter relay) is the part of an automobile which relays a large electric current to the starter motor, which in turn sets the engine in motion. In many vehicles the solenoid also engages the starter pinion with the ring gear of the engine.
Spark Plugs and Wires
A spark plug is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the engine. A spark plug has a metal threaded shell, electrically isolated from a central electrode by a porcelain insulator.
Spark plug wires are critical to deliver spark to a high performance engine. It's important to choose the right type of spark plug wires for your car. You should consider heat resistance, chemical resistance, ohm rating, RFI Suppression, cut-to-fit or direct fit and even the color when choosing high performance spark plug wires.