How to Get the Ignition Timing Right
An engine is responsible for supplying necessary power to all of the moving parts of a vehicle. Even though the engine receives the proper amount of fuel and air, it is critical that the air-fuel mixture is ignited at the proper time to extract the maximum power from it. This is when ignition timing becomes critical. The ignition spark should be created precisely to ensure full combustion of the air-fuel mixture. This article discusses the importance of ignition timing on engine performance and what might go wrong in a car with improper ignition timing.
The ignition timing determines when the air-fuel combination in the combustion chamber of the engine is ignited. The timing is expressed in degrees prior to or following the piston’s top dead center (TDC). When the ignition system is configured to ignite the fuel precisely at TDC, the ignition timing is said to be 0 degrees. The ignition timing is said to be advanced if the ignition system is adjusted to generate the spark before the piston reaches TDC. To obtain the best power output at various engine speeds, the ignition time should be adjusted appropriately. Generally, the ignition timing is advanced to maximize the engine’s power output.
The spark is typically ignited 10-30 degrees before the piston hits top dead center (TDC). Regardless of engine speed, the air-fuel mixture burns at the same rate. The faster the engine runs, the greater the advance in ignition timing is required to maintain maximum pressure at the same position in the engine cycle. Earlier models required manual ignition timing adjustment. They calibrated the advance timing using either vacuum or centrifugal advances. In modern automobiles, the Engine Control Unit (ECU) determines the amount of advance required at a particular engine speed. The ignition timing is retarded in some automobiles. This is typically done when lowering emissions takes precedence over increasing electricity production. The proper time to ignite the fuel is determined by a variety of parameters, including the engine displacement, the octane rating of the fuel, the compression ratio of the engine, the quality of the spark plugs, and the engine’s intake pressure. Typically, when an engine is modified or upgraded, the ignition timing is altered.
The Consequences of Incorrect Ignition Timing. Improper ignition timing can result in a variety of engine malfunctions, including banging or pinging, difficult starting, overheating, higher fuel consumption, and decreased power output.
Pinging or Knocking is a fairly frequent engine symptom. When the ignition timing is set ahead of the ideal advance time, knocking occurs. In some instances, the spark plugs ignite the fuel-air mixture while the engine is still in compression, resulting in incorrect combustion. Modern automobiles incorporate knock sensors to reduce engine knocking. Click here for a thorough description of knock sensors.
A Difficult Start can occur as a result of either an accelerated or delayed ignition. In both circumstances, the engine will not produce the maximum amount of power, resulting in trouble starting the car.
Overheating is one of the signs that the air-fuel mixture was ignited prematurely. This results in the engine producing more heat than usual.
In general, incorrect ignition timing reduces the engine’s power and efficiency. When the air-fuel mixture is ignited at a moment different than the optimal time, incorrect combustion occurs. This will also result in a drop in fuel economy.