What is spark retardation?

Ignition Retarding. Ignition timing is measured in degrees of a crankshaft rotation before top dead center (BDTC). Spark plugs need to fire at the right time, which can be achieved by advancing or retarding the timing of the engine. Ignition timing retarding causes the spark plug to fire later in the compression stroke …

What is spark advance and why is it important?

Spark timing is associated with the delay in initiating and propagating combustion of the air-fuel mixture. To complete combustion before the piston starts its expansion stroke, the spark must be initiated a few crank angle degrees (advance) before the piston reaches top dead center.

What causes pre detonation and spark knock?

What Are The Other Causes Of, Engine Spark Knock:

• Faulty (EGR) Valve.
• Knock Sensor Failure.
• Excessive Carbon Buildup.
• Vacuum Leaks.
• Higher That Normal Compression.
• Exhaust Back Pressure.
• Substandard Fuel.
• Excessive Engine Temperatures.

What is the importance of having spark advance mechanism in the ignition system?

Timing advance is required because it takes time to burn the air-fuel mixture. Igniting the mixture before the piston reaches TDC will allow the mixture to fully burn soon after the piston reaches TDC.

What is engine retardation?

What is Engine timing retardation? With the word retard, it is clear that something is being delayed or slowed. In this case, it is the ignition Spark of the Engine. Now delaying the ignition timing means igniting the spark after the piston has already started traveling down.

What is a good spark ADV?

That is typically 15-35 degrees before TDC (top dead center) of the power stroke depending on the engine speed. Best power is achieved when ignition timing is set to fire the spark ahead of time to reach that peak pressure at about 2 degrees after TDC.

Which of the following will cause a spark knock?

Spark knock (detonation) is an erratic form of combustion that occurs when multiple flame fronts occur simultaneously inside a combustion chamber. Detonation occurs because fuel is subjected to either too much pressure, too much heat or both.

How do you know that the spark plug is detonated what is the cause of detonation?

Answer: Detonation, or engine knock, occurs simply when fuel pre-ignites before the piston reaches scheduled spark ignition. Detonation is generally caused by excessive heat, excessive cylinder pressure, improper ignition timing, inadequate fuel octane or a combination of these.

Does advancing timing lean or rich?

If you advance your timming you will have to richin the fuel mixture, if you retard the timming then you would have to lean out your carb for it to run best.

What is the function of retarder?

Retarders are used to further improve the braking performance on commercial vehicles. Like engine brakes, they are wear-free continuous brakes. Retarders relieve the service brake and increase the active safety and cost-effectiveness of commercial vehicles. Retarders are installed in a commercial vehicle’s drive train.

How does spark advance and retarding the spark timings affect detonation?

Advancing and retarding the spark timings affects the temperature factors and hence detonation or knocking. Tendency to knock increases with spark advance and decreases with spark retardation. Spark retardation is one major step in controlling detonation.

What are the effects of ignition timing retarding?

Ignition timing retarding causes the spark plug to fire later in the compression stroke. The effects of retarding ignition timing include reducing engine detonation, which is combustion inside the cylinders after the spark plug fires.

Why does the spark knock when the piston is advancing?

Advancing the spark: when the spark is advance the burning gas is compressed by rising piston and therefore the increase in temperature will be much more and hence the knocking tendency increases. To avoid detonation spark must be retarded.

What is knocking in a fire engine?

In other words, knocking is the explosion of air/fuel mixture, that is not set off by the flame front created by the spark delivered. The solution to this is retarding spark.