CHEAP NGK SPARK PLUGS OF THE WRONG HEAT RANGE CAUSE PROBLEMS!

CHEAP NGK SPARK PLUGS OF THE WRONG HEAT RANGE CAUSE PROBLEMS
We see and hear of people who have put BCR8ES or very similar spark plugs in there Cooper S R53 and had problems with misfire/spluttering/holding back etc or other running problems . These may have been included with a pulley upgrade . The facts are these are a very cheap Copper Core Large electrode plug of too Colder heat range.
1) NGK are a great brand, but these are £1.50 each copper core plugs that have soft ( fast wearing) electrodes. The wear rate is reduced by using wide electrodes, the downside is the quality/voltage of the spark is much inferior.
2) The number (‘8′ in this case) is the heat range .The higher the number the colder the plug . Note you need the correct heat range whereby the plug loses( or keeps) just the right amount of heat to maintain optimum plug tip temperature . A higher number is not a better plug ! Most heat ranges are the same or similar price within a certain model of plug anyway . Too low a heat range and yes the plug tip could get too hot and in extreme circumstances could melt and drop off (Not good), but equally too cold a plug doesn’t get enough tip temperature to burn off the fuel . This results in plug fouling/misfire. Normally this will occur on a colder ie not fully warmed up engine. Maybe worse on a cold morning or when sitting in traffic . ie when internal engine temps are lower than average…
The answer is to use only the correct heat range , std is 6 but 7 is correct for almost all modified R53s ( inc our GTT 400bhp car). Also you need smaller electrodes for higher voltage spark and more ‘space’ for flame spread . And finally those tips need to be hardest material AND on both electrodes ( Double Iridium) . IX is the only range that give this . Laser Iridium are lower spec, and Laser Plarinum one lower again . The cheap copper core plugs we see are inferior even to the std 4 electrode types! We have offered only one plug since 2003 …The right one and best one! When we fit these plugs we ALWAYS apply a little copperslip to the threads and a little di-electric grease to the nipples…..We also tighten the plugs up to correct tightness so they don’t come loose a few thousand miles later then rip the remaining threads out of the head !…You have been warned