In older internal combustion engines, the car ignition distributor is a crucial component of the ignition system. Its primary function is to distribute high-voltage electricity from the ignition coil to the spark plugs in the correct firing order. Here's a breakdown of the key roles and functions of a car ignition distributor:
High-Voltage Distribution:
The ignition distributor receives high-voltage electricity from the ignition coil. This high-voltage current is generated by the coil when the primary circuit is interrupted, inducing a high-voltage surge in the secondary winding.
Rotating Rotor:
The distributor features a rotating rotor mounted on a shaft inside the distributor housing. The rotor is typically driven by the engine's camshaft.
Cap and Contacts:
The rotor is positioned inside a distributor cap, which contains electrical contacts. As the rotor spins, it passes close to each contact point in the cap. Each contact corresponds to one of the engine's cylinders.
Firing Order:
The arrangement of the contacts in the distributor cap corresponds to the engine's firing order. The firing order determines the sequence in which the spark plugs receive the high-voltage current to ignite the air-fuel mixture in each cylinder.
Spark Plug Connection:
From each contact in the distributor cap, a spark plug wire extends to the respective spark plug in the engine. When the rotor aligns with a specific contact, high-voltage electricity is transferred to the corresponding spark plug wire, initiating the spark in the cylinder.
Ignition Timing:
The distributor also plays a crucial role in setting the ignition timing. By adjusting the position of the distributor, the timing of the spark can be advanced or retarded. Proper ignition timing ensures optimal combustion efficiency and engine performance.
Centrifugal and Vacuum Advance Mechanisms:
Many distributors are equipped with advance mechanisms to adjust the timing based on engine speed (centrifugal advance) and engine load (vacuum advance). These mechanisms help optimize ignition timing under varying driving conditions.
Maintenance Components:
The distributor cap and rotor are wear components that may require periodic replacement.