After
reading a recent article in a trade publication I decided to share some of the
facts with you. Spark plugs are not what they seem. Every time a new plug
catalogue comes out there are more and more weird and wonderful numbers in it,
most of these are for the new lean burn engines with extended service life. Once
over there were only a couple of popular plugs but today every car has its own
unique plug and only that one will do its job correctly. Heat ranges are a very
important part of keeping your plug life long and getting maximum out of the air
fuel mixture that is injected your engine.
Plug Gap
Plugs
have a space or air gap as it is called between the centre electrode and the
earth wire on the end. This gap is very important for good ignition of the
mixture in the cylinder. If this gap is wrong or the plug type is wrong this can
cause poor ignition and misfires, which in turn can cause poor performance and
high fuel consumption. The gap on modern plugs is getting wider. this is to help
ignite the leaner mixtures that are in use by manufacturers. The plug can manage
this because of the high outputs of the modern ignition system with their
frightening outputs.
Resistors
Resistors
have been around in plugs for a long time. Today’s car needs resistors not
just to meet the radio interference
legislation but also to
stop radiation causing problems with modern engine management systems.
Heat Range
Plugs
were first made with steel but the heat range was very poor, making it hard to
cover engine conditions fully as it warmed up. Also the spark plug range had to
be large to cover all the different engines. They were next made with copper
because of its ability to conduct heat and electricity well this was used to
increase the heat range of plugs. Now there are platinum tips. Platinum conducts
heat and electricity exceptionally well, this makes it possible to reduce the
size of the electrode and open the air gap to help ignite the lean fuel air
mixture in the cylinder
Electrodes
Spark
plug electrodes are made of all sorts of precious metals. Multiple electrodes
are a cheap way of extending service life, and with the new platinum
tips, this makes it possible to reduce the size of the electrode and open the
air gap . This helps
ignite
the fuel air in the cylinder. At the same time as increasing
the service life. Today's
plugs can last up to 100,000 miles.
