Bosch plugs do multiple sparks by virtue of the fact that they are high resistance, thus dribble your spark energy out slowly. This makes them good for some turbo engines 'coz if the spark gets "blown out" there's still charge in the wires for it to re-establish itself. However, they will make weak plug wires etc flash over 'coz the spark tries to find an easier route. Many are the cars that don't seem to like them, Fords and Dodges seem to be in this category. I believe this is because they have relatively high ignition output from the factory, in the 30KV plus range which is reckoned to be HEI when upgrading. Additionally, if you read up about the benefits of plug indexing, and then look at a Bosch +4... you'll notice that whatever you do, it shrouds the spark.
As pointed out, the mileage interval possible on the +4s is partly due to the fact that they have 4x more "edge" for the spark to start from, and also because lower ignition energy density from the higher resistance means that gap erosion is less severe.
Platinum is a good catalyst for many reactions, this makes it good in a motor right? Not really, it will decompose ethanol vapor into water and CO2 while glowing red, it will also catalyze H2 into H2O and glow red... This often happens BEFORE the correct ignition point in a hot motor, thus you get preignition issues. Therefore, platinum plugs may run poorly in combo with E10 or higher, or with a HHO or other hydrogen assist system.
__________________
I remember The RoadWarrior..To understand who he was, you have to go back to another time..the world was powered by the black fuel & the desert sprouted great cities..Gone now, swept away..two mighty warrior tribes went to war & touched off a blaze which engulfed them all. Without fuel, they were nothing..thundering machines sputtered & stopped..Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice
|