What will retarding timing do?
Retarding the timing means the plug fires later in the compression stroke (closer to TDC). Retarding the timing can help reduce Detonation. This is because the cylinder pressure won’t reach it’s max until the piston is already headed back down on the Power Stroke.
What are the symptoms of incorrect ignition timing?
Incorrect ignition timing, can cause several engine problems such as:
- Knocking or Pinging.
- Difficult Starting.
- Excessive Engine Heat.
- Increased Fuel Consumption.
- Reduced Power Output.
Why does a lower octane fuel prevent pre-ignition?
With lower or higher octane fuel, as the octane number increases, it becomes harder and harder to burn. This helps prevent pre-ignition. Retarding the timing is moving timing closer to TDC towards the end of the compression cycle.
Why does the flame front move slower in octane gas?
Likewise, the flame front moves slower in higher octane gas, which requires more ignition advance, but also allows higher compression. Another cause of octane knock is carbon buildup in the combustion chamber. The root cause is because carbon retains its heat better than iron.
What makes an engine have a higher octane rating?
One of the important ways to get more power out of an engine is to raise the compression, meaning that the fuel/air mixture gets squeezed more before the spark goes off. This makes the fuel mixture burn faster and hotter, providing more power. This is where the Octane rating comes in.
Why is timing so important in an engine?
Proper timing is all-important to the thermo-efficiency of the engine. The first thing to keep in mind is that fuel burns at a certain rate in an engine regardless of the rpm. All automotive engines today have four strokes. Let’s use a single cylinder in an engine as an illustration to demonstrate how all four strokes work.