One of the key factors that makes a spark plug work well, or not, is the size of the gap between the electrodes. If the gap is too small, the spark will likely be too weak and cause the engine to run poorly or with poor efficiency.
The larger the gap, the more voltage is needed to jump the gap. Most experienced tuners know that increasing the gap size increases the spark area exposed to the air-fuel mixture, which maximizes burn efficiency. For this reason, most racers add high-energy ignition systems.
Too small of a gap may give too weak of a spark to complete the combustion process within the engine; too wide of a gap can lead to the spark plug not firing correctly, causing misfires at high speeds.
For most racing applications, you usually want the plug gap to be between 0.020 and 0.040 of an inch. Most engine builders seem to settle around 0.035 of an inch. Factors such as the type of ignition you run, cylinder heads, fuel and even timing can affect how much gap will work best for you.
Gapping fine-wire spark plugs
While most NGK spark plugs are pre-gapped, there are occasions when the gap requires adjustment. Care must be taken to avoid bending or breaking off the fine-wire electrodes. NGK recommends a round wire-style or pin gauge gap tool to measure the gap.
These plugs are pre-gapped at . 044".
As the spark plugs wear, the spark plug gaps widen, also weakening MPG. This is because the wider the spark plug gap, the more voltage is required to arch between the electrodes. The smoother the combustion process, the lower the demand for engine power and the lower the demand for fuel.
The distance between the tip of the spark plug and the central electrode is called the "spark plug gap" and is a key factor in the function of a spark plug. Spark plug gaps for car engines are typically 0.6 to 1.8 mm (0.024 to 0.071 in).
The discharge voltage rises in proportion to the spark plug gap. The spark plug gap widens bit by bit as the electrode wears, so high discharge voltage becomes necessary and misfire occurs more easily.
Spark plugs that are gapped incorrectly can cause an engine to miss, or run erratically, especially during idle. The incorrect spark plug gaps can cause uneven firing of individual spark plugs and delay engine combustion; both of which can cause an engine to miss or idle erratically.
A tighter spark plug gap can increase power and reduce emissions. This video is sponsored by NGK and NTK. You may have noticed that spark plug gaps have been getting smaller while engines have been getting making more power. The reason for the shift in the gap and power is the timing of the spark.
Yes an incorrect spark plug gap can cause a rough idle.
A wider spark plug gap means that the distance between the electrodes is increased, which can affect the way the spark plug operates. A wider spark plug gap can create a larger spark, which may be desirable in some high-performance engines, as it can ignite the air/fuel mixture more quickly and efficiently.
It sure does. Smaller than spec spark plug gap will inadvertently cause the plug to fire at lower voltage than in the wide-gap setting. This means less energy into the spark.
Changing the spark plug gap won't affect the ignition timing, but it will have some affects on the ability of the spark plug to ignite the fuel.
FACT #4: YOU SHOULD CHANGE SPARK PLUGS EVERY 100K MILES OR SO. So, if good spark plugs are the key to avoiding these issues, how long do spark plugs last, exactly? The general rule of thumb about how often to change spark plugs is that they should be replaced after about 100,000 miles of driving.
In most cases, you'll see a noticeable difference in performance after replacing your spark plugs and wires. The engine will run smoother and faster, and the car will have better acceleration.
While spark plugs don't technically increase your engine's horsepower, they bring it back to its optimal combustion level. In simple words, your car will run as if it's new with optimum acceleration control and improved fuel economy!
Platinum spark plugs
These plugs are a high value for the money, giving you considerably higher performance, gas mileage, and longevity that's second only to iridium plugs. They can last about twice as long as their copper counterparts, making them a popular choice in city cars and some sports cars.
However, if the spark plug gap is too large, the spark is unlikely to consistently "jump" across the long distance between electrodes, thus leading to a rough-running engine or one that doesn't run at all.
In most cases your Iridium Power plugs do not need to be gapped. Even with small variations in the factory set gap the ultra-efficient firing power design will compensate for those small variations.
Every time a spark plug creates an arc of electricity, it very minimally shortens the electrodes. Over time, the gap between the electrodes grows larger. As this gap increases, more electricity is needed to spark ignition of the air/fuel mixture.
Lubricate Spark Plugs & Other Parts
For part of your car repair and maintenance, you can use WD-40 to remove carbon residue, and keep moisture away from spark plugs and spark plug wires.