How to Set Gaps in Spark Plugs
For modified and customized car engines, the right gap on a set of spark plugs can make the engine perform better and provide greater power. Spark plugs provide the ignition source needed to light up the fuel-air mixture in the cylinder, and the correct gap setting can help your engine maximize the power found in fuel mixtures. If you need to gap your spark plugs, here are the steps you need to take.
When to Gap Spark Plugs
Spark plugs work by passing an arc of electricity between two electrodes: the center electrode and gap electrode. Like an open flame, the electric arc packs up enough power to ignite the fuel-air mixture found in the cylinder as the engine operates. There is a very precise distance on a spark plug’s gap, which is calculated by auto designers and engineers to ensure that the spark plug delivers the maximum power for every cycle of the engine.
Auto modders and car customizers often tweak the gap of a spark plug to provide more power and optimize the efficiency of a car engine. Unless you have not modified your engine, or if your car comes with a manufacturer-specified engine, you should never set gaps on your spark plugs. The electrodes and wires on a spark plug are precision-designed to ignite the fuel-air mixture. You do need to re-gap your spark plugs if:
Your engine suffers from frequent cold starts, or if the engine does not start at all.
If you have a customized engine that falters at certain speeds.
If you think that modifying the gap on spark plugs will provide a significant increase in power and performance.
Tools
To gap your spark plugs, you need the following tools:
Ratchet, socket set, and 12-inch extension
Your car manual
Feeler gauge
Spark plug gapping tool (can be bought from any auto supply store)
Needle-nose pliers (if you don’t have a gapping tool)
Steps
Work with spark plugs one at a time. Carefully remove the spark plug from the receptacle using a ratchet wrench and socket set.
Inspect the condition of the spark plug first to see if it’s dirty or damaged. You can often get a significant increase in power and performance if you replace your spark plugs, or if you simply clean them.
If you need to re-gap the spark plugs, refer to the owner’s manual for the correct gap setting between the center electrode and the gap electrode. Set the gapping tool to the distance indicated on the owner’s manual.
Use the feeler gauge to measure the gap on the spark plug. The gap should be the same as the distance indicated on the manual, down to the last millimeter.
To fix or reset the gap, slip the gapping tool in the recessed area between the center electrode and the gap electrode. To widen the gap, push the gapping tool in the spark plug until the gap is set at the proper distance. Do not scratch or damage the porcelain or ceramic coating on the center electrode, or else you have to replace the entire spark plug.
Replace the newly-gapped spark plug back into the receptacle. Make sure the wires and the plugs are secure on the spark plug assembly.
Do the same for the rest of the spark plugs.
Customized engines are all about a significant increase in performance and power. With the right gap on your spark plugs, you can maximize every volt needed to put that spark back in your driving experience.