tændingsvinkel

Tændingsvinkel, often translated as ignition timing, refers to the precise moment within the engine cycle when the spark plug ignites the air-fuel mixture in the combustion chamber. This timing is crucial for optimal engine performance, fuel efficiency, and emissions control.

The ignition timing is typically measured in degrees of crankshaft rotation before top dead center (BTDC). Top dead center (TDC) is the point where the piston is at its highest position in the cylinder. Advancing the ignition timing means igniting the mixture earlier, while retarding it means igniting it later.

Various factors influence the ideal tændingsvinkel, including engine speed, engine load, fuel octane rating, and temperature. At higher engine speeds, the ignition is usually advanced to allow more time for the flame front to propagate and produce maximum power as the piston moves downwards. Under heavy load, the timing might be slightly retarded to prevent knocking or detonation, which occurs when the fuel-air mixture ignites prematurely due to excessive heat and pressure.

Modern engines use sophisticated electronic control units (ECUs) to dynamically adjust the tændingsvinkel in real-time, continuously optimizing it for current operating conditions. Older engines often relied on mechanical distributors with vacuum and centrifugal advance mechanisms to achieve similar, albeit less precise, adjustments. Incorrect ignition timing can lead to reduced power, poor fuel economy, increased emissions, and potential engine damage.