V12s and their mysterious coil packs...
03-02-2018, 04:20 PM
#1
Junior Member
Thread Starter
V12s and their mysterious coil packs...
Upfront...NO mine are not bad. But it IS getting time for a set of plugs. Other than a set of BMC air filters this car is bone stock.
QUESTION #1: HOW exactly does the coil pack fire the plugs? (READ, before posting obligatory smart a$$ answer) While I am reasonable certain that the coil fires off multiple sparks per combustion stroke...do the two plugs fire simultaneously, or is one followed by the other or (like on my Moto Guzzi) the plug closest to the exhaust valve only fires on closed throttle, sitting idle under load?
QUESTION #2: IF they fire simultaneously, seems to me the plugs should be indexed. Are they indexed from the factory? Because once I pull them, there will be no way to know. Does Benz offer a "shim kit" for the gasket seat plugs? OR...suggestions?
QUESTION #3: IF both plugs fire simultaneously, why not gap one at .022 and the other (pointing at the intake valve) at .025? Seems that this would be a good way to get the best of both arguments for a slightly closed gap VS a stock gap. (there is a HUGE thread elsewhere on this forum on this argument)
Let the opinions fly!
QUESTION #1: HOW exactly does the coil pack fire the plugs? (READ, before posting obligatory smart a$$ answer) While I am reasonable certain that the coil fires off multiple sparks per combustion stroke...do the two plugs fire simultaneously, or is one followed by the other or (like on my Moto Guzzi) the plug closest to the exhaust valve only fires on closed throttle, sitting idle under load?
QUESTION #2: IF they fire simultaneously, seems to me the plugs should be indexed. Are they indexed from the factory? Because once I pull them, there will be no way to know. Does Benz offer a "shim kit" for the gasket seat plugs? OR...suggestions?
QUESTION #3: IF both plugs fire simultaneously, why not gap one at .022 and the other (pointing at the intake valve) at .025? Seems that this would be a good way to get the best of both arguments for a slightly closed gap VS a stock gap. (there is a HUGE thread elsewhere on this forum on this argument)
Let the opinions fly!
