The gap between the electrodes of a spark plug must be properly adjusted to ensure proper operation of an engine. The electrode gap affects the sparking time of the spark plug, which in turn affects the ignition of fuel and air in the engine. Increasing the distance increases the spark, thus maximizing the efficiency of some tuned engines. You can measure and adjust the distance of the electrodes yourself. Go to step 1 for more information.
Steps
Part 1 of 2: Measuring the distance
Step 1. Find out the correct electrode gap for your type of car
You need to know the correct distance between the two electrodes on the end of a spark plug for your car if you are going to buy new spark plugs, or if you want to check new spark plugs before installing them, or if you want to see how your current spark plugs work. check.
- The distance differs per car, but usually the correct distance is between 0.7 and 15 mm. You can look it up in your car owner's manual or you can go to an auto parts store and ask there.
- With modified motors, the distance is smaller because the motor has to deliver more power. In general you can say the following: the more force, the smaller the distance.
Step 2. Choose a tool to determine the distance
There are several tools you can use to measure the distance between the electrodes on a spark plug, some are more suitable for newer spark plugs as they can contain delicate precious metals. Most devices also have a flat edge that can be used to bend the lower electrode. That way, the distance can be slightly adjusted.
- The cheapest option is usually a coin-shaped distance meter. This works by moving the edge of the "coin" between the electrodes until you reach the point where the coin becomes too thick. On the edge you can then read what the distance is at that point. This is a good tool if you want to check the operation of older spark plugs, but the downside is that you can accidentally increase the distance with it.
- A rangefinder with pieces of wire on the outside works much the same, but this type has pieces of wire of different thickness attached around the coin.
- A "feeler gauge" with different blade thicknesses is an effective and versatile tool. It is built like a pocket knife and has a number of fold-out blades of different thicknesses, some have wire on the end, some don't. The blades can be placed between the electrodes to determine the distance. You can use several knives at the same time to measure greater distances. This type is useful to use when adjusting the distance.
Step 3. Clean the spark plug
If you have just taken the spark plug out of the packaging, this will probably not be necessary, but a used spark plug should be cleaned first with a clean rag. Over time, some whitish soot can build up on the contact points of a spark plug, so to get an accurate reading you will need to clean the points first.
You can use some quick drying alcohol (90%) to clean the contacts if they are very dirty. It is possible that the spark plug needs to be replaced if it is very dirty or if the contact points have turned black. In that case, consider buying new ones
Step 4. Measure the distance by placing the appropriate thickness of the feeler gauge between the electrodes
Take your feeler gauge and insert the appropriate gauge blade or wire between the ends of the spark plug electrodes. Or if you're using a coin, move the coin through the electrodes to measure the distance.
Part 2 of 2: Adjusting the distance
Step 1. Determine if the distance needs to be adjusted
If the size suitable for your car does not touch the electrodes when measuring, then the distance is too large. If it does not fit between the electrodes, the distance is too small and it should be made slightly larger. If it fits exactly, you can install the spark plug without adjusting.
Most modern spark plugs do not require adjustment before installation. But if you have a tuned engine, you may be more interested in a different distance. In this case, adjust the spark plugs as desired
Step 2. Use your feeler gauge to adjust the bottom electrode
If you hold the spark plug so that the electrodes are pointing downwards, you can carefully bend the lower electrode. Bend towards the other electrode if you want to decrease the distance, bend away from the other electrode if you want to increase the distance.
- Never bend the electrode more than half a millimeter at a time. The electrode can't hold a lot of pressure, so you have to be careful.
- If you are not successful in bending the electrode, you can try bending it by pressing the electrode on a flat surface, such as a table.
Step 3. Measure the distance again and adjust again if necessary
Be careful not to make contact with the electrode in the center of the spark plug, as you could damage the core. If it breaks or short circuits, throw away the spark plug and buy a new one.
Step 4. Be very careful
If the electrode breaks, all the effort has been for nothing. Use only a small amount of force to bend the electrode and do not bend the electrode too far.
Tips
- Make sure the distance between the electrodes on the different spark plugs are as equal as possible.
- Different colors of the electrode tips may indicate a problem with the motor.
- Do not overtighten the spark plugs. Most cylinder heads are made of aluminum, it doesn't take much to damage the threads.
- Spark plugs are relatively inexpensive, so it doesn't hurt to replace them regularly.