Engine Performance and Ignition Timing

Ignition Timing

• Indicates the synchronization between the camshaft and crankshaft, crucial for engine performance.
• Refers to the critical moment when the spark plug fires, ensuring proper fuel combustion.
• Measured in crankshaft degrees from the top dead center (TDC) to the moment combustion is complete.

Engine Load

• Represents the force resisting the crankshaft rotation, affecting engine efficiency.
• Criteria include conditions like uphill driving and towing trailers, stressing the engine more than normal.

Variability of Ignition Timing

• Must adjust to multiple factors: engine temperature, load, and RPM, to optimize performance
• Increased load or RPM typically requires advanced timing for combustion efficiency.

Primary Circuit Components

• Key components of the primary circuit include the battery, ignition switch, and triggering device.
• The spark plug is not part of this circuit, serving a different role in ignition.

Coil Secondary Winding

• Connects to the negative terminal and high tension tower, delivering high voltage to the spark plug.
• Composed of 15,000 to 25,000 turns of fine copper wire, increasing voltage for effective spark generation.

Effect of Engine Speed on Ignition Timing

• As engine speed rises, ignition timing must be advanced to ensure timely fuel combustion and engine efficiency.

Coil Primary Winding

• Ends are connected from positive to negative terminals, forming the primary circuit that initiates the ignition process.

Dwell Time

• Defined as the duration when the points are closed within the ignition system, allowing for a build-up of energy in the ignition coil before discharge.

Action of Ignition Points

• When the ignition points open, it triggers the spark plug to fire, igniting the air-fuel mixture in the combustion chamber.