The piston engines used in airplanes also have two plugs per cylinder, for the same reason. The ignition system uses two very powerful magnetos, one hooked up to the top plugs and the other to the bottom plugs in each cylinder. Same for a top fuel motor putting out 8000 hp at 9000 rpm, or 1000 hp per cylinder. :shock: Sometimes the old technology is still the best.Rick said:Now if you want to get really dazed and confused, the Civic IMA has 2 spark plugs per cylinder, so a 4 cylinder engine uses 8 spark plugs....Ok I'll stop ranting now.
Because when you cut threads into any material the chances for it to "begin" at the same place are very slim.Holicow said:Why would the plugs be different in each cylinder?
You're absolutely right. THAT is the difference between the 4 spark-plugs.dan said:Hi everyone-
So maybe the difference in the plugs (A,B,C,D) is a 90 degree change in the angle of the direction of the gap in relation to the threads?
I used to think that too, until I started doing accident investigations. To be accurate: the reason for the twin magnetos is redundancy, sort of. Some "dual" magnetos are actually in one unit, and many of them are on a common drive that is much more likely to fail than an individual mag. So, not so redundant, but better than just one. Mags rarely fail.james said:That's only half the reason, though you do notice a distinct RPM drop when only one set is operating. The main reason, though, is redundancy