How a spark plug works
Car Spark Plug Split Diagram
The main feature of a spark plug is a cerarmic Insulator inside a threaded metal shank Through the middle of the cerarmic body runs a conductor which links the outer terminal of the plug (on to which the plug lead and cap are Clipped) and the centre electrode Visable Inside the hollow shank Reaching out towards the centre electrode from the rim of the plug tip Is Ihe side electrode The spark plug gap is the space between the tips of the two electrodes
Car Spark Plug Length Differance
There are two main types of spark plug,The most common type has a small metal compression washer or gasket to seal the plug tightly to the cylinder head. The other type has a taper seat machined on it which mates wIth a seat around the spark plug hole In the cylinder head. Each of these two basic types of plug can have up to four further design variations. The reach of a plug refers to the length of the thread shank and determines the perssion of the plug tip inside the cornbustion chamber it is vital to have plugs of the correct reach too long a shank might allow the piston to toch the plug tip And too short a shank will result in poor ignition.
Car Spark Plug 4 Side Electrodes
A plugs temperature range denotes the ability of the plug's center electrode to conduct away heat a cold plug cools faster than a hot plug as it has a shorter heat path between the Ihe center electrode and metal body To provide radio suppression Interlerence some plugs have an electrical resistor inside the cermaic body for example Champion's RN9Y plug IS Identical in operation 10 the N9Y type but the A In the code denotes that it has a resistor Finally, there can be some variation in plug lip design A few models have up 10 four side electrodes for better sparking The type of plug that a car needs wllI normally be given in the owner's handbook or workshop manual Always use that type or the exact equivalent from another plug maker's range.